HT66F488_489v100.pdf

A/D 8-Bit Flash MCU with EEPROM
HT66F488/HT66F489
Revision: V1.00
Date: ������������������
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Table of Contents
Features............................................................................................................. 7
CPU Features.......................................................................................................................... 7
Peripheral Features.................................................................................................................. 7
General Description ......................................................................................... 8
Selection Table.................................................................................................. 8
Block Diagram................................................................................................... 9
Pin Assignment................................................................................................. 9
Pin Descriptions............................................................................................. 10
Absolute Maximum Ratings........................................................................... 13
D.C. Characteristics........................................................................................ 13
A.C. Characteristics........................................................................................ 15
LVR & LVD Characteristics............................................................................ 16
ADC Electrical Characteristics ..................................................................... 17
Power on Reset Electrical Characteristics................................................... 17
System Architecture....................................................................................... 18
Clocking and Pipelining.......................................................................................................... 18
Program Counter.................................................................................................................... 19
Stack...................................................................................................................................... 20
Arithmetic and Logic Unit – ALU............................................................................................ 20
Flash Program Memory.................................................................................. 21
Structure................................................................................................................................. 21
Special Vectors...................................................................................................................... 21
Look-up Table......................................................................................................................... 22
Table Program Example......................................................................................................... 22
In Circuit Programming.......................................................................................................... 23
On-Chip Debug Support – OCDS.......................................................................................... 24
RAM Data Memory.......................................................................................... 25
Structure................................................................................................................................. 25
General Purpose Data Memory ............................................................................................ 25
Special Purpose Data Memory ............................................................................................. 26
Special Function Register Description......................................................... 27
Indirect Addressing Register – IAR0, IAR1, IAR2.................................................................. 27
Memory Pointers – MP0, MP1L, MP1H, MP2L, MP2H.......................................................... 27
Accumulator – ACC................................................................................................................ 29
Program Counter Low Register – PCL................................................................................... 29
Look-up Table Registers – TBLP, TBHP, TBLH...................................................................... 29
Status Register – STATUS .................................................................................................... 29
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HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
EEPROM Data Memory................................................................................... 31
EEPROM Data Memory Structure......................................................................................... 31
EEPROM Registers............................................................................................................... 31
Reading Data from the EEPROM ......................................................................................... 33
Writing Data to the EEPROM................................................................................................. 33
Write Protection...................................................................................................................... 33
EEPROM Interrupt................................................................................................................. 33
Programming Considerations................................................................................................. 34
Oscillator......................................................................................................... 35
Oscillator Overview................................................................................................................ 35
System Clock Configurations................................................................................................. 35
External Crystal/Ceramic Oscillator – HXT............................................................................ 36
Internal RC Oscillator – HIRC................................................................................................ 37
External 32.768kHz Crystal Oscillator – LXT......................................................................... 37
Internal 32kHz Oscillator – LIRC............................................................................................ 38
Supplementary Oscillator....................................................................................................... 38
Operating Modes and System Clocks.......................................................... 39
System Clocks....................................................................................................................... 39
System Operation Modes....................................................................................................... 40
Control Register..................................................................................................................... 41
Fast Wake-up......................................................................................................................... 42
Operating Mode Switching .................................................................................................... 43
Standby Current Considerations............................................................................................ 45
Wake-up................................................................................................................................. 45
Programming Considerations................................................................................................. 46
Watchdog Timer.............................................................................................. 46
Watchdog Timer Clock Source............................................................................................... 46
Watchdog Timer Control Register.......................................................................................... 46
Watchdog Timer Operation.................................................................................................... 48
Reset and Initialisation................................................................................... 49
Reset Functions..................................................................................................................... 49
Reset Initial Conditions.......................................................................................................... 51
Input/Output Ports.......................................................................................... 54
Pull-high Resistors................................................................................................................. 55
Port A Wake-up...................................................................................................................... 55
I/O Port Control Registers...................................................................................................... 55
Pin-shared Functions............................................................................................................. 55
I/O Pin Structures................................................................................................................... 55
I/O Port source current selection............................................................................................ 57
Programming Considerations................................................................................................. 59
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HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Timer Modules – TM....................................................................................... 59
Introduction............................................................................................................................ 59
TM Operation......................................................................................................................... 60
TM Clock Source.................................................................................................................... 60
TM Interrupts.......................................................................................................................... 60
TM External Pins.................................................................................................................... 60
TM Input/Output Pin Control Register.................................................................................... 61
Programming Considerations................................................................................................. 63
Compact Type TM – CTM............................................................................... 64
Compact TM Operation.......................................................................................................... 64
Compact Type TM Register Description................................................................................ 65
Compact Type TM Operating Modes..................................................................................... 69
Standard Type TM – STM............................................................................... 75
Standard TM Operation.......................................................................................................... 75
Standard Type TM Register Description................................................................................ 76
Standard Type TM Operating Modes..................................................................................... 80
Periodic Type TM – PTM0, PTM1................................................................... 90
Periodic TM Operation........................................................................................................... 90
PTM register description........................................................................................................ 91
Periodic Type TM Operating Modes....................................................................................... 95
Analog to Digital Converter......................................................................... 104
A/D Overview....................................................................................................................... 104
A/D Converter Register Description..................................................................................... 104
A/D Converter Data Registers – ADRL, ADRH.................................................................... 105
A/D Converter Control Registers – ADCR0, ADCR1, ACERL.............................................. 105
A/D Operation...................................................................................................................... 108
A/D Input Pins.......................................................................................................................110
Summary of A/D Conversion Steps.......................................................................................110
Programming Considerations................................................................................................112
A/D Transfer Function...........................................................................................................112
A/D Programming Examples.................................................................................................113
Serial Interface Module – SIM.......................................................................115
SPI Interface.........................................................................................................................115
SPI Register..........................................................................................................................116
SPI Communication..............................................................................................................119
I2C Interface......................................................................................................................... 121
I2C Register.......................................................................................................................... 122
I2C Bus Communication....................................................................................................... 126
I2C Bus Start Signal.............................................................................................................. 127
Slave Address...................................................................................................................... 127
I2C Bus Read/Write Signal................................................................................................... 127
I2C Bus Slave Address Acknowledge Signal........................................................................ 127
I2C Bus Data and Acknowledge Signal................................................................................ 128
I2C Time-out Control............................................................................................................. 129
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HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
UART Module Serial Interface..................................................................... 131
UART External Interface...................................................................................................... 131
UART Data Transfer Scheme.............................................................................................. 132
UART Status and Control Registers.................................................................................... 132
Baud Rate Generator........................................................................................................... 138
Calculating the register and error values............................................................................. 138
UART Setup and Control..................................................................................................... 139
Managing receiver errors..................................................................................................... 143
UART Module Interrupt Structure......................................................................................... 144
Address detect mode........................................................................................................... 145
UART Module Power Down and Wake-up........................................................................... 146
Interrupts....................................................................................................... 146
Interrupt Registers................................................................................................................ 146
Interrupt Operation............................................................................................................... 154
External Interrupt.................................................................................................................. 155
Multi-function Interrupt......................................................................................................... 156
A/D Converter Interrupt........................................................................................................ 156
Time Base Interrupts............................................................................................................ 156
Serial Interface Module Interrupts........................................................................................ 157
EEPROM Interrupt............................................................................................................... 158
TM Interrupts........................................................................................................................ 158
LVD Interrupt ....................................................................................................................... 158
UART Interrupt..................................................................................................................... 158
Interrupt Wake-up Function.................................................................................................. 159
Programming Considerations............................................................................................... 159
Software LCD Driver..................................................................................... 160
LCD operation...................................................................................................................... 160
LCD Control Registers......................................................................................................... 160
LCD waveform..................................................................................................................... 165
Low Voltage Detector – LVD........................................................................ 167
LVD Register........................................................................................................................ 167
LVD Operation...................................................................................................................... 168
Configuration Option.................................................................................... 169
Application Circuit........................................................................................ 169
Instruction Set............................................................................................... 170
Introduction.......................................................................................................................... 170
Instruction Timing................................................................................................................. 170
Moving and Transferring Data.............................................................................................. 170
Arithmetic Operations........................................................................................................... 170
Logical and Rotate Operation.............................................................................................. 171
Branches and Control Transfer............................................................................................ 171
Bit Operations...................................................................................................................... 171
Table Read Operations........................................................................................................ 171
Other Operations.................................................................................................................. 171
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September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Instruction Set Summary............................................................................. 172
Table Conventions................................................................................................................ 172
Extended Instruction Set...................................................................................................... 174
Instruction Definition.................................................................................... 176
Extended Instruction Definition............................................................................................ 185
Package Information.................................................................................... 192
28-pin SOP (300mil) Outline Dimensions............................................................................ 193
28-pin SSOP (150mil) Outline Dimensions.......................................................................... 194
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September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Features
CPU Features
• Operating Voltage
♦♦
fSYS = 8MHz: 2.2V~5.5V
♦♦
fSYS = 10MHz: 2.7V~5.5V
♦♦
fSYS = 12MHz: 3.3V~5.5V
♦♦
fSYS = 16MHz: 4.5V~5.5V
• Up to 0.25μs instruction cycle with 16MHz system clock at VDD=5V
• Power down and wake-up functions to reduce power consumption
• Four Oscillators:
• External High Frequency Crystal – HXT
• External 32.768kHz Crystal-- LXT
• Internal High Frequency RC -- HIRC
• Internal 32kHz -- LIRC
• Fully intergrated internal 8MHz oscillator requires no external components
• Multi-mode operation: NORMAL, SLOW, IDLE and SLEEP
• All instructions executed in one to three instruction cycles
• Table read instructions
• 115 powerful instructions
• 8-level subroutine nesting
• Bit manipulation instruction
Peripheral Features
• Flash Program Memory: 8K×16 (HT66F489)/4K×16 (HT66F488)
• RAM Data Memory: 384×8
• EEPROM Memory: 64×8
• Watchdog Timer function
• 30 bidirectional I/O lines
• LED driver
• 1/3 Bias Software LCD
• Serial Interface Module – SIM for SPI or I2C
• UART Function
• Six pin-shared external interrupts
• Multiple Timer Module for time measure, input capture, compare match output, PWM output
function or single pulse output function
• Dual Time-Base functions for generation of fixed time interrupt signals
• 8-channel 12-bit resolution A/D converter
• Low voltage reset function
• Low voltage detector function
• Package: 28-pin SOP/SSOP
Rev. 1.00
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September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
General Description
The devices are 8-bit high performance RISC architecture microcontroller, designed especially for
applications that interface directly to analog signals, such as those from sensor. Offering users the
convenience of Flash Memory multi-programming features, this device also includes a wide range
of functions and features. Other memory includes an area of RAM Data Memory as well as an area
of EEPROM memory for storage of non-volatile data such as serial numbers, calibration data etc.
Analog features include a multi-channel 12-bit A/D converter. Multiple and extremely flexible Timer
Modules provide timing, pulse generation and PWM generation functions. Communication with
the outside world catered for by including fully integrated SPI, I2C and UART interface functions,
three popular interfaces which provide designers with a means of easy communication with external
peripheral hardware. Protective features such as an internal Watchdog Timer, Low Voltage Reset
and Low Voltage Detector coupled with excellent noise immunity and ESD protection ensure that
reliable operation is maintained in hostile electrical environments.
A full choice of HXT, LXT, HIRC and LIRC oscillator functions are provided including a fully
integrated system oscillator which requires no external components for its implementation. The
ability to operate and switch dynamically between a range of operating modes using different
clock sources gives users the ability to optimise microcontroller operation and minimize power
consumption.
The inclusion of flexible I/O programming features, Time-Base functions along with many
other features ensure that the device will find excellent use in applications such as sensor signal
processing, chargers, motor driving, industrial control, consumer product, subsystem controller, etc.
Selection Table
Most features are common to all devices, the main feature distinguishing them are Memory capacity
and whether EEPROM or not. The following table summarises the main features of each device.
Part No.
Program
Memory
HT66F488
4K×16
HT66F489
8K×16
Part No.
HT66F488
HT66F489
Rev. 1.00
Data
Memory
Data
EEPROM
I/O
R-type LCD
(1/3 Bias)
High Current
LED Output
384×8
64×8
26
6(SCOM/SSEG)
+20SSEG
26
Timer
Module
RTC
A/D
Interface
Stack
Package
10-bit CTM×1
16-bit STM×1
10-bit PTM×2
√
12-bit×8
SPI/I2C, UART
8
28SOP/SSOP
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September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Block Diagram
Watchdog
Timer
Flash/EEPROM
Programming Circuitry
(ICP)/OCDS
EEPROM
Data
Memory
Flash
Program
Memory
HXT/ LXT
Oscillators
Internal RC
Oscillators
Low
Voltage
Detect
8-bit
RISC
MCU
Core
Low
Voltage
Reset
RAM Data
Memory
Reset
Circuit
Interrupt
Controller
Time
Bases
12-bit A/D
Converter
SIM
UART
I/O
CTM
STM
PTMs
Software
LCD
Pin Assignment
PC4/AN4/SSEG22
1
28
PC5/AN5/INT3/SSEG21
PC3/AN3/SSEG23
2
27
PC6/AN6/VREF/INT2/SSEG20
PC0/AN2/SSEG26
3
26
PB1/PTCK0/INT1/AN7/SSEG17
PB7/STP/RX/AN1/SSEG27
4
25
PB2/CTP/INT0/SSEG16
PB6/STCK/TX/AN0/SSEG28
5
24
PB5/SSEG29
6
23
PB3/OSC2/XT2/SSEG15
PB4/OSC1/XT1/ICPCK/SSEG14
VSS/AVSS
7
22
VDD/AVDD
PD0/ICPDA/SCOM0/SSEG0
PD1/SCOM1/SSEG1
8
21
PA7/CTCK/SSEG13
9
20
PA6/PTCK1/SCS/SSEG12
PD2/SCOM2/SSEG2
10
19
PA5/PTP1/SCK/SCL/SSEG11
PD3/SCOM3/SSEG3
11
18
PA4/SDI/SDA/SSEG10
PD4/SCOM4/SSEG4
12
17
PA3/SDO/SSEG9
PD5/SCOM5/SSEG5
13
16
PA2/OCDSCK/SSEG8
PA0/OCDSDA/SSEG6
14
15
PA1/SSEG7
HT66F488/489
HT66V488/489
28 SOP-A/SSOP-A
Note: 1. If the pin-shared pin functions have multiple outputs simultaneously, the function used is determined by
the corresponding software control bit or configuration option.
2. AVDD&VDD means the VDD and AVDD are the double bonding. VSS&AVSS means the VSS and
AVSS are the double bonding.
3. HT66V488/489 is the EV chip, and the OCDSDA, OCDSCK pins are for EV chip only.
Rev. 1.00
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September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Pin Descriptions
Pin Name
PA0/OCDSDA/
SSEG6
PA1/SSEG7
PA2/OCDSCK/
SSEG8
PA3/SDO/SSEG9
PA4/SDI/SDA/
SSEG10
Function
OPT
I/T
PA0
PAWU
PAPU
ST
CMOS General purpose I/O. Register enable pull-up and wake-up
OCDSDA
—
ST
CMOS OCDS Data/Address pin, for EV chip only
SSEG6
SLCDC2
—
CMOS Software LCD SEG output
PA1
PAWU
PAPU
ST
CMOS General purpose I/O. Register enable pull-up and wake-up
SSEG7
SLCDC2
—
CMOS Software LCD SEG output
PA2
PAWU
PAPU
ST
CMOS General purpose I/O. Register enable pull-up and wake-up
OCDSCK
—
ST
SSEG8
SLCDC2
—
CMOS Software LCD SEG output
PA3
PAWU
PAPU
ST
CMOS General purpose I/O. Register enable pull-up and wake-up
—
—
CMOS SPI Data output
SLCDC2
—
CMOS Software LCD SEG output
PA4
PAWU
PAPU
ST
CMOS General purpose I/O. Register enable pull-up and wake-up
SDI
—
ST
SDA
—
ST
NMOS I2C Data
CMOS Software LCD SEG output
PA5
ST
CMOS General purpose I/O. Register enable pull-up and wake-up
PTP1
TMPC0
ST
CMOS PTM1 input/output
SCK
—
ST
CMOS SPI Serial Clock
SCL
—
ST
NMOS I2C Clock
—
CMOS Software LCD SEG output
CMOS General purpose I/O. Register enable pull-up and wake-up
PA6
PAWU
PAPU
ST
PTCK1
—
ST
SCS
—
ST
CMOS SPI slaver selection
PB2/CTP/INT0/
SSEG16
PTM1 input
—
CMOS Software LCD SEG output
PA7
ST
CMOS General purpose I/O. Register enable pull-up and wake-up
CTCK
—
ST
—
CTM input
—
CMOS Software LCD SEG output
PB0
PBPU
ST
CMOS General purpose I/O. Register enable pull-up.
PTP0
TMPC0
ST
CMOS PTM0 output
INT4
—
ST
—
External interrupt input
—
CMOS Software LCD SEG output
CMOS General purpose I/O. Register enable pull-up.
PB1
PBPU
ST
PTCK0
—
ST
—
PTM0 input
INT1
—
ST
—
External interrupt input
AN7
ACERL
AN
—
ADC input
SSEG17 SLCDC3
—
CMOS Software LCD SEG output
PB2
PBPU
ST
CMOS General purpose I/O. Register enable pull-up.
CTP
TMPC0
ST
CMOS CTM output
INT0
—
ST
SSEG16 SLCDC3
Rev. 1.00
—
PAWU
PAPU
SSEG18 SLCDC3
PB1/PTCK0/
INT1/AN7/
SSEG17
SPI Data input
—
SSEG13 SLCDC2
PB0/PTP0/INT4/
SSEG18
—
PAWU
PAPU
SSEG12 SLCDC2
PA7/CTCK/
SSEG13
OCDS Clock pin, for EV chip only.
SDO
SSEG11 SLCDC2
PA6/PTCK1/SCS/
SSEG12
—
Description
SSEG9
SSEG10 SLCDC2
PA5/PTP1/SCK/
SCL/SSEG11
O/T
—
—
External interrupt input
CMOS Software LCD SEG output
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September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Pin Name
PB3/OSC2/XT2/
SSEG15
Function
OPT
I/T
PB3
PBPU
ST
OSC2
CO
—
HXT
HXT pin
XT2
CO
—
LXT
LXT pin
SSEG15 SLCDC3
PB4/OSC1/
XT1/ICPCK/
SSEG14
PB7/STP/RX/
AN1/SSEG27
PC0/AN2/
SSEG26
PC1/SSEG25
PC2/SSEG24
PC3/AN3/
SSEG23
PC4/AN4/
SSEG22
PC5/AN5/INT3/
SSEG21
Rev. 1.00
CMOS General purpose I/O. Register enable pull-up.
ST
CO
HXT
—
HXT pin
XT1
CO
LXT
—
LXT pin
ICPCK
—
ST
—
ICP Clock pin
—
CMOS Software LCD SEG output
ST
CMOS General purpose I/O. Register enable pull-up.
—
CMOS Software LCD SEG output
PBPU
ST
CMOS General purpose I/O. Register enable pull-up.
STCK
—
ST
TX
—
—
AN0
ACERL
AN
SSEG28 SLCDC4
—
CMOS Software LCD SEG output
PB5
PBPU
SSEG29 SLCDC4
—
STM input
CMOS UART data transmission output
—
ADC input
PB7
PBPU
ST
CMOS General purpose I/O. Register enable pull-up.
STP
TMPC0
ST
CMOS STM input/output
RX
—
ST
AN1
ACERL
AN
SSEG27 SLCDC4
—
CMOS Software LCD SEG output
CMOS General purpose I/O. Register enable pull-up.
—
UART data received input
—
ADC input
PC0
PCPU
ST
AN2
ACERL
AN
SSEG26 SLCDC4
—
CMOS Software LCD SEG output
ST
CMOS General purpose I/O. Register enable pull-up.
—
CMOS Software LCD SEG output
ST
CMOS General purpose I/O. Register enable pull-up.
PC1
PCPU
SSEG25 SLCDC4
PC2
PCPU
SSEG24 SLCDC4
—
ADC input
—
CMOS Software LCD SEG output
PC3
PCPU
ST
CMOS General purpose I/O. Register enable pull-up.
AN3
ACERL
AN
SSEG23 SLCDC4
—
CMOS Software LCD SEG output
CMOS General purpose I/O. Register enable pull-up.
—
ADC input
PC4
PCPU
ST
AN4
ACERL
AN
SSEG22 SLCDC4
—
CMOS Software LCD SEG output
CMOS General purpose I/O. Register enable pull-up.
—
ADC input
PC5
PCPU
ST
AN5
ACERL
AN
—
ADC input
INT3
—
ST
—
External interrupt input
—
CMOS Software LCD SEG output
CMOS General purpose I/O. Register enable pull-up.
PC6
PCPU
ST
AN6
ACERL
AN
—
ADC input
VREF
ADCR1
AN
—
ADC Reference voltage input
INT2
—
ST
—
External interrupt input
SSEG20 SLCDC3
PC7/INT5/
SSEG19
CMOS Software LCD SEG output
PBPU
SSEG21 SLCDC3
PC6/AN6/VREF/
INT2/SSEG20
—
PB4
PB6
PB6/STCK/TX/
AN0/SSEG28
Description
OSC1
SSEG14 SLCDC3
PB5/SSEG29
O/T
CMOS General purpose I/O. Register enable pull-up.
—
CMOS Software LCD SEG output
PC7
PCPU
ST
CMOS General purpose I/O. Register enable pull-up.
INT5
—
ST
SSEG19 SLCDC3
—
—
External interrupt input
CMOS Software LCD SEG output
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September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Pin Name
PD0/ICPDA/
SCOM0/SSEG0
PD1/SCOM1/
SSEG1
PD2/SCOM2/
SSEG2
PD3/SCOM3/
SSEG3
PD4/SCOM4/
SSEG4
PD5/SCOM5/
SSEG5
VDD/AVDD
VSS/AVSS
Function
OPT
I/T
PD0
PDPU
ST
CMOS General purpose I/O. Register enable pull-up.
O/T
Description
ICPDA
—
ST
CMOS ICP Data/Address pin
SCOM0
SLCDC0
SLCDC1
—
CMOS Software LCD COM output
SSEG0
SLCDC0
SLCDC1
—
CMOS Software LCD SEG output
PD1
PDPU
ST
CMOS General purpose I/O. Register enable pull-up.
SCOM1
SLCDC0
SLCDC1
—
CMOS Software LCD COM output
SSEG1
SLCDC0
SLCDC1
—
CMOS Software LCD SEG output
PD2
PDPU
ST
CMOS General purpose I/O. Register enable pull-up.
SCOM2
SLCDC0
SLCDC1
—
CMOS Software LCD COM output
SSEG2
SLCDC0
SLCDC1
—
CMOS Software LCD SEG output
PD3
PDPU
ST
CMOS General purpose I/O. Register enable pull-up.
SCOM3
SLCDC0
SLCDC1
—
CMOS Software LCD COM output
SSEG3
SLCDC0
SLCDC1
—
CMOS Software LCD SEG output
PD4
PDPU
ST
CMOS General purpose I/O. Register enable pull-up.
SCOM4
SLCDC1
—
CMOS Software LCD COM output
SSEG4
SLCDC1
—
CMOS Software LCD SEG output
PD5
PDPU
ST
CMOS General purpose I/O. Register enable pull-up.
SCOM5
SLCDC1
—
CMOS Software LCD COM output
SSEG5
SLCDC1
—
CMOS Software LCD SEG output
VDD
—
PWR
—
Positive Power Supply
AVDD
—
PWR
—
Analog Positive Power Supply
VSS
—
PWR
—
Negative Power Supply. Ground
AVSS
—
PWR
—
Analog Negative Power Supply
Note: I/T: Input type;
O/T: Output type
OP: Optional by configuration option (CO) or register option
PWR: Power;
CO: Configuration option; ST: Schmitt Trigger input
CMOS: CMOS output;
AN: Analog input pin
HXT: High frequency crystal oscillator
LXT: Low frequency crystal oscillator
*: VDD is the device power supply while AVDD is the ADC power supply. The AVDD pin is bonded
together internally with VDD.
**: VSS is the device ground pin while AVSS is the ADC ground pin. The AVSS pin is bonded together
internally with VSS.
Note: 1. This Pin Description Summary table describes all resources which may not be connected to external pins.
2. For 28-SKDIP/SOP package PB0, PC1, PC2 and PC7 are not bonded to external pins and should be
properly configured to avoid a floating condition which will result in additional current leakage.
Rev. 1.00
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September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Absolute Maximum Ratings
Supply Voltage ..................................................................................................VSS−0.3V to VSS+6.0V
Input Voltage .................................................................................................... VSS−0.3V to VDD+0.3V
Storage Temperature ...................................................................................................... 50˚C to 125˚C
Operating Temperature . ................................................................................................... 40˚C to 85˚C
IOH Total .................................................................................................................................... -150mA
IOL Total ..................................................................................................................................... 100mA
Total Power Dissipation ........................................................................................................... 500mW
Note: T hese are stress ratings only. Stresses exceeding the range specified under “Absolute
Maximum Ratings” may cause substantial damage to these devices. Functional operation of
these devices at other conditions beyond those listed in the specification is not implied and
prolonged exposure to extreme conditions may affect devices reliability.
D.C. Characteristics
Ta=25°C
Symbol
VDD
Parameter
Operating Voltage
(HXT)
Operating Voltage
(HIRC)
Test Conditons
Min.
Typ.
Max.
Unit
fSYS=8MHz
2.2
—
5.5
V
fSYS=10MHz
2.7
—
5.5
V
fSYS=12MHz
3.3
—
5.5
V
fSYS=16MHz
4.5
—
5.5
V
—
fSYS=8MHz
2.2
—
5.5
V
3V
No load, fSYS= fH =8MHz
ADC off, WDT enable
—
1.0
1.5
mA
—
2.5
4.0
mA
No load, fSYS= fH =10MHz
ADC off, WDT enable
—
1.2
2.0
mA
—
2.8
4.5
mA
5V
No load, fSYS= fH =12MHz
ADC off, WDT enable
—
3.5
5.5
mA
5V
No load, fSYS= fH =16MHz
ADC off, WDT enable
—
4.5
7.0
mA
—
1.2
2.0
mA
—
2.8
4.5
mA
5V
No load, fSYS= fH/2,
ADC off, WDT enable
—
2.1
3.3
mA
5V
No load, fSYS= fH/4,
ADC off, WDT enable
—
1.6
2.5
mA
5V
No load, fSYS= fH/8,
ADC off, WDT enable
—
1.2
2.5
mA
5V
No load, fSYS= fH/16
ADC off, WDT enable
—
1.1
2.0
mA
5V
No load, fSYS= fH/32,
ADC off, WDT enable
—
1.0
2.0
mA
5V
No load, fSYS= fH/64,
ADC off, WDT enable
—
1.0
2.0
mA
—
5V
3V
Operating Current, Normal Mode,
fSYS =fH (HXT), fS =fLIRC
Operating Current, Normal Mode,
fSYS=fH(HIRC), fS=fLXT or fLIRC
IDD
Operating Current, Slow Mode 1
fH =12MHz (HXT), fS =fLIRC
Rev. 1.00
Conditons
VDD
5V
3V
5V
No load, fSYS= fH =8MHz
ADC off, WDT enable
13
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Symbol
Parameter
Test Conditons
3V
IDD
ISTB
Operating Current, Slow Mode 0
fSYS=fS=fLXT
VIL
VIH
IOL
5V
3V
5V
Operating Current, Slow Mode 0
fSYS=fS=fLIRC
3V
Standby Current, IDLE Mode
(fSYS=off, fS=fSUB= fLIRC)
3V
Standby Current, SLEEP Mode
(fSYS=off, fS=fSUB= fLIRC)
3V
Standby Current, SLEEP Mode
fSYS=12MHz (HXT),
fSYS =off, fS=fSUB= fLIRC
Input Low Voltage for I/O Ports
Input High Voltage for I/O Ports
I/O Port Sink Current
Large Sink I/O (PD)
I/O Port Sink Current
(PA, PB, PC)
5V
5V
5V
—
IBIAS
Bias current for LCD
Unit
No load, ADC off,
WDT enable, LXTLP=0
—
15
25
μA
—
30
50
μA
No load, ADC off,
WDT enable, LXTLP=1
—
10
20
μA
—
25
45
μA
No load, ADC off,
WDT enable
—
10
20
μA
—
20
40
μA
No load, system HALT,
IDLEN=1, WDT enable
—
1.3
3.0
μA
—
2.2
5.0
μA
No load, system HALT,
IDLEN=0, WDT enable
—
1.3
3.0
μA
—
2.2
5.0
μA
—
65
95
μA
No load, system HALT,
ADC off, WDT enable
—
0
—
1.5
V
—
0
—
0.2VDD
V
5V
—
3.5
—
5
V
—
—
0.8VDD
—
VDD
V
200
—
mA
5V
VOL=1.5V
120
3V
VOH=0.1VDD
15
30
—
mA
5V
VOH=0.1VDD
30
60
—
mA
3V
VOL=0.1VDD
15
30
—
mA
5V
VOL=0.1VDD
30
60
—
mA
VOH=0.9VDD, select full source
current option
-3.0
-6.0
—
mA
VOH=0.9VDD, select 10/22 full
source current option
-1.5
-3.0
—
mA
VOH=0.9VDD, select 7/22 full
source current option
-1.0
-2.0
—
mA
VOH=0.9VDD, select 4/22 full
source current option
-0.8
-1.5
—
mA
VOH=0.9VDD, select full source
current option
-9.0
-18.0
—
mA
VOH=0.9VDD, select 10/22 full
source current option
-4.0
-8.0
—
mA
VOH=0.9VDD, select 7/22 full
source current option
-3.0
-6.0
—
mA
VOH=0.9VDD, select 4/22 full
source current option
-2.0
-3.6
—
mA
20
60
100
kΩ
I/O Port Source Current
(PA, PB, PC, PD)
Pull-high Resistance
Max.
—
5V
RPH
Typ.
5V
3V
IOH
Min.
Conditons
VDD
3V
—
5V
5V
10
30
50
kΩ
ISEL[1:0]=00
4.2
8.3
13
μA
ISEL[1:0]=01
8.3
16.7
25
μA
ISEL[1:0]=10
25
50
75
μA
ISEL[1:0]=11
50
100
150
μA
VSEG_H
1/3 bias LCD SEG output (SEG_H) 2.2~5.5V No load
0.645
0.67
0.695
VDD
VSEG_L
1/3 bias LCD SEG output (SEG_L) 2.2~5.5V No load
0.305
0.33
0.355
VDD
Rev. 1.00
14
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
A.C. Characteristics
Ta=25°C
Symbol
Parameter
System clock (HXT)
fSYS
System clock (LIRC)
tSST
tRSTD
Min.
Typ.
2.2V~5.5V
0.4
2.7V~5.5V
0.4
3.3V~5.5V
Conditions
—
4.5V~5.5V
System clock (HIRC)
System clock (LXT)
tTIMER
Test Conditons
VDD
xTCKn Input Pin Minimun Pulse width
System Start-up Timer Period
(wake up from HALT)
5V
—
5V
—
Unit
—
8
MHz
—
10
MHz
0.4
—
12
MHz
0.4
—
16
MHz
-2%
8
2%
MHz
—
32768
—
Hz
-10%
32
+10%
kHz
-50%
32
+60%
kHz
0.06
0.15
0.3
μs
fSYS=HXT
128
—
—
tSYS
fSYS=LXT
128
—
—
tSYS
fSYS=HIRC
16
—
—
tSYS
fSYS=LIRC
2
—
—
tSYS
Ta=0°C~70°C
—
Ta=25°C
2.2V~5.5V Ta=-40°C~85°C
—
Max.
—
System Start-up Timer Period
(wake up from HALT, fSYS on at HALT)
—
—
2
—
—
tSYS
System Reset Delay Time
(POR, LVR, LVR S/W, WDT S/W reset)
—
—
25
50
100
ms
System Reset Delay Time
(WDT reset)
—
—
8.3
16.7
33.3
ms
tINT
Interrupt Minimum Pulse Width
—
—
1
3.3
5
μs
tLVR
Low Voltage width to reset
—
—
120
240
480
μs
tSRESET
Software Reset width to reset
—
—
45
90
120
μs
tEERD
EEPROM Read Time
—
—
1
2
4
tSYS
tEEWR
EEPROM Write Time
—
—
1
2
4
ms
Note: tSYS=1/fSYS
Rev. 1.00
15
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
LVR & LVD Characteristics
Ta=25°C
Symbol
VLVR
VLVD
ILVR
Parameter
Low Voltage Reset Voltage
Low Voltage Detector Voltage
Additional Power
Consumption if LVR is Used
Test Conditions
—
—
3V
5V
3V
ILVD
Additional Power
Consumption if LVD is Used
Conditions
VDD
5V
3V
5V
Min.
Typ.
LVR Enable, 2.10V option
2.10
LVR Enable, 2.55V option
2.55
LVR Enable, 3.15V option
-5%
3.15
Max.
Unit
V
+5%
V
V
LVR Enable, 3.80V option
3.80
V
LVDEN = 1, VLVD = 2.0V
2.0
V
LVDEN = 1, VLVD = 2.2V
2.2
V
LVDEN = 1, VLVD = 2.4V
2.4
V
LVDEN = 1, VLVD = 2.7V
LVDEN = 1, VLVD = 3.0V
-5%
2.7
3.0
+5%
V
V
LVDEN = 1, VLVD = 3.3V
3.3
LVDEN = 1, VLVD = 3.6V
3.6
V
LVDEN = 1, VLVD = 4.0V
4.0
V
LVR disable→LVR enable
LVD disable→LVD enable
(LVR disable)
LVD disable→LVD enable
(LVR enable)
V
—
30
45
—
60
90
μA
μA
─
40
60
μA
─
75
115
μA
─
30
45
μA
─
60
90
μA
tLVR
Low Voltage Width to Reset
—
—
120
240
480
μs
tLVD
Low Voltage Width to Interrupt
—
—
65
125
250
μs
—
LVD disable→LVD enable
(LVR enable)
—
—
15
μs
—
LVD disable→LVD enable
(LVR disable)
—
—
200
μs
tLVDS
Rev. 1.00
LVDO stable time
16
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
ADC Electrical Characteristics
Ta=25°C
Symbol
Test Conditons
Parameter
Min. Typ.
VDD
Conditons
2.7V~5.5V
—
0
3V/5V
—
2.0
Max.
Unit
—
AVDD/VREF
V
—
AVDD+0.1
V
tAD
VAD
ADC Input Voltage
VREF
ADC Reference Voltage
tADC
A/D Conversion Time
2.7V~5.5V 12-bit ADC
—
16
—
tAD
A/D Clock Period
2.7V~5.5V
—
0.5
—
10
μs
tON2ST
A/D Converter On-to-Start Time
2.7V~5.5V
—
2
—
—
μs
DNL1
A/D Differential Non-linearity
3V/5V
VREF=VDD, tAD=0.5μs
Ta=25°C
-3
—
+3
LSB
DNL2
A/D Differential Non-linearity
3V/5V
VREF=VDD, tAD=0.5μs
Ta=-40°C ~ 85°C
-4
—
+4
LSB
INL1
A/D Integral Non-linearity
3V/5V
VREF=VDD, tAD=0.5μs
Ta=25°C
-4
—
+4
LSB
INL2
A/D Integral Non-linearity
3V/5V
VREF=VDD, tAD=0.5μs
Ta=-40°C ~ 85°C
-6
—
+6
LSB
IADC
Additonal Power consumption if A/D
Converter is used
3V
—
1.0
2.0
mA
—
1.5
3.0
mA
tBGS
VBG turn on stable time
—
—
10
—
—
ms
VBG
Bandgap reference with buffer voltage
—
—
+5%
V
IBG
Additional power consumption if
reference with buffer is used
—
—
300
μA
No load, tAD=0.5μs
5V
-5% 1.25
—
200
Power on Reset Electrical Characteristics
Ta = 25°C
Symbol
Test Conditions
Parameter
VDD
Conditions
Min.
Typ.
Max.
Unit
VPOR
VDD Start Voltage to Ensure Power-on Reset
─
─
─
─
100
mV
RRVDD
VDD Rising Rate to Ensure Power-on Reset
─
─
0.035
─
─
V/ms
tPOR
Minimum time for VDD Stays at VPOR to
ensure Power-on Reset
─
─
10
─
─
ms
Rev. 1.00
17
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
System Architecture
A key factor in the high-performance features of the Holtek range of microcontrollers is attributed
to their internal system architecture. The device takes advantage of the usual features found within
RISC microcontrollers providing increased speed of operation and Periodic performance. The
pipelining scheme is implemented in such a way that instruction fetching and instruction execution are
overlapped, hence instructions are effectively executed in one cycle, with the exception of branch or
call instructions. An 8-bit wide ALU is used in practically all instruction set operations, which carries
out arithmetic operations, logic operations, rotation, increment, decrement, branch decisions, etc.
The internal data path is simplified by moving data through the Accumulator and the ALU. Certain
internal registers are implemented in the Data Memory and can be directly or indirectly addressed.
The simple addressing methods of these registers along with additional architectural features ensure
that a minimum of external components is required to provide a functional I/O and A/D control
system with maximum reliability and flexibility. This makes the device suitable for low-cost,
high-volume production for controller applications.
Clocking and Pipelining
The main system clock, derived from either a HXT, LXT, HIRC or LIRC oscillator is subdivided
into four internally generated non-overlapping clocks, T1~T4. The Program Counter is incremented
at the beginning of the T1 clock during which time a new instruction is fetched. The remaining
T2~T4 clocks carry out the decoding and execution functions. In this way, one T1~T4 clock
cycle forms one instruction cycle. Although the fetching and execution of instructions takes place
in consecutive instruction cycles, the pipelining structure of the microcontroller ensures that
instructions are effectively executed in one instruction cycle. The exception to this are instructions
where the contents of the Program Counter are changed, such as subroutine calls or jumps, in which
case the instruction will take one more instruction cycle to execute.


   
   
System Clock and Pipelining
Rev. 1.00
18
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
For instructions involving branches, such as jump or call instructions, two machine cycles are
required to complete instruction execution. An extra cycle is required as the program takes one
cycle to first obtain the actual jump or call address and then another cycle to actually execute the
branch. The requirement for this extra cycle should be taken into account by programmers in timing
sensitive applications.
  
    
 Instruction Fetching
Program Counter
During program execution, the Program Counter is used to keep track of the address of the
next instruction to be executed. It is automatically incremented by one each time an instruction
is executed except for instructions, such as “JMP” or “CALL” that demand a jump to a nonconsecutive Program Memory address. Only the lower 8 bits, known as the Program Counter Low
Register, are directly addressable by the application program.
When executing instructions requiring jumps to non-consecutive addresses such as a jump
instruction, a subroutine call, interrupt or reset, etc., the microcontroller manages program control
by loading the required address into the Program Counter. For conditional skip instructions, once
the condition has been met, the next instruction, which has already been fetched during the present
instruction execution, is discarded and a dummy cycle takes its place while the correct instruction is
obtained.
Device
Program Counter
Program Counter High byte
PCL Register
HT66F488
PC11~PC8
PCL7~PCL0
HT66F489
PC12~PC8
PCL7~PCL0
The lower byte of the Program Counter, known as the Program Counter Low register or PCL, is
available for program control and is a readable and writeable register. By transferring data directly
into this register, a short program jump can be executed directly, however, as only this low byte
is available for manipulation, the jumps are limited to the present page of memory, that is 256
locations. When such program jumps are executed it should also be noted that a dummy cycle
will be inserted. Manipulating the PCL register may cause program branching, so an extra cycle is
needed to pre-fetch.
Rev. 1.00
19
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Stack
This is a special part of the memory which is used to save the contents of the Program Counter
only. The stack is neither part of the data nor part of the program space, and is neither readable nor
writeable. The activated level is indexed by the Stack Pointer, and is neither readable nor writeable.
At a subroutine call or interrupt acknowledge signal, the contents of the Program Counter are pushed
onto the stack. At the end of a subroutine or an interrupt routine, signaled by a return instruction,
RET or RETI, the Program Counter is restored to its previous value from the stack. After a device
reset, the Stack Pointer will point to the top of the stack.
If the stack is full and an enabled interrupt takes place, the interrupt request flag will be recorded
but the acknowledge signal will be inhibited. When the Stack Pointer is decremented, by RET or
RETI, the interrupt will be serviced. This feature prevents stack overflow allowing the programmer
to use the structure more easily. However, when the stack is full, a CALL subroutine instruction can
still be executed which will result in a stack overflow. Precautions should be taken to avoid such
cases which might cause unpredictable program branching. If the stack is overflow, the first Program
Counter save in the stack will be lost.
P ro g ra m
T o p o f S ta c k
S ta c k L e v e l 1
S ta c k L e v e l 2
S ta c k
P o in te r
B o tto m
C o u n te r
S ta c k L e v e l 3
o f S ta c k
P ro g ra m
M e m o ry
S ta c k L e v e l 8
Arithmetic and Logic Unit – ALU
The arithmetic-logic unit or ALU is a critical area of the microcontroller that carries out arithmetic
and logic operations of the instruction set. Connected to the main microcontroller data bus, the ALU
receives related instruction codes and performs the required arithmetic or logical operations after
which the result will be placed in the specified register. As these ALU calculation or operations may
result in carry, borrow or other status changes, the status register will be correspondingly updated to
reflect these changes. The ALU supports the following functions:
• Arithmetic operations: ADD, ADDM, ADC, ADCM, SUB, SUBM, SBC, SBCM, DAA, LADD,
LADDM, LADC, LADCM, LSUB, LSUBM, LSBC, LSBCM, LDAA
• Logic operations: AND, OR, XOR, ANDM, ORM, XORM, CPL, CPLA, LAND, LANDM,
LOR, LORM, LXOR, LXORM, LCPL, LCPLA
• Rotation: RRA, RR, RRCA, RRC, RLA, RL, RLCA, RLC, LRR, LRRA, LRRCA, LRRC,
LRLA, LRLCA, LRLC
• Increment and Decrement: INCA, INC, DECA, DEC, LINCA, LINC, LDECA, LDEC
• Branch decision: JMP, SZ, SZA, SNZ, SIZ, SDZ, SIZA, SDZA, CALL, RET, RETI, LSNZ, LSZ,
LSZA, LSIZ, LSDZ, LSIZA, LSDZA
Rev. 1.00
20
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Flash Program Memory
The Program Memory is the location where the user code or program is stored. For this device the
Program Memory is Flash type, which means it can be programmed and re-programmed a large
number of times, allowing the user the convenience of code modification on the same device.
By using the appropriate programming tools, this Flash device offers users the flexibility to
conveniently debug and develop their applications while also offering a means of field programming
and updating.
Structure
The Program Memory has a capacity of 4K×16 bits to 8K×16 bits. The Program Memory is
addressed by the Program Counter and also contains data, table information and interrupt entries.
Table data, which can be setup in any location within the Program Memory, is addressed by a
separate table pointer register.
Device
Capacity
HT66F488
4K×16
HT66F489
8K×16
HT66F489
HT66F488
0000H
0000H
Reset
0004H
Interrupt Vector
Interrupt Vector
003CH
003CH
0FFFH
Reset
0004H
16 bits
1FFFH
16 bits
Program Memory Structure
Special Vectors
Within the Program Memory, certain locations are reserved for the reset and interrupts. The location
000H is reserved for use by the device reset for program initialisation. After a device reset is
initiated, the program will jump to this location and begin execution.
Rev. 1.00
21
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Look-up Table
Any location within the Program Memory can be defined as a look-up table where programmers can
store fixed data. To use the look-up table, the table pointer must first be setup by placing the address
of the look up data to be retrieved in the table pointer register, TBLP and TBHP. These registers
define the total address of the look-up table.
After setting up the table pointer, the table data can be retrieved from the Program Memory using
the “TABRD [m]” or “TABRDL [m]” instructions respectively when the memory [m] is located
in sector 0. If the memory [m] is located in other sectors, the table data can be retrieved from the
Program Memory using the “LTABRD [m]” or “LTABRDL [m]” instructions respectively. When the
instruction is executed, the lower order table byte from the Program Memory will be transferred to
the user defined Data Memory register [m] as specified in the instruction. The higher order table data
byte from the Program Memory will be transferred to the TBLH special register. Any unused bits in
this transferred higher order byte will be read as 0.
The accompanying diagram illustrates the addressing data flow of the look-up table.
A d d re s s
L a s t p a g e o r
T B H P R e g is te r
T B L P R e g is te r
D a ta
1 6 b its
R e g is te r T B L H
U s e r S e le c te d
R e g is te r
H ig h B y te
L o w B y te
Table Program Example
The following example shows how the table pointer and table data is defined and retrieved from the
microcontroller. This example uses raw table data located in the Program Memory which is stored
there using the ORG statement. The value at this ORG statement is “F00H” which refers to the start
address of the last page within the 4K words Program Memory of the HT66F488 device. The table
pointer is setup here to have an initial value of “06H”. This will ensure that the first data read from
the data table will be at the Program Memory address “F06H” or 6 locations after the start of the
present page. Note that the value for the table pointer is referenced to the first address of the last
page if the “TABRDL [m]” or “LTABRDL [m]” instruction is being used. The high byte of the table
data which in this case is equal to zero will be transferred to the TBLH register automatically when
the “TABRDL [m]” or “LTABRDL [m]” instruction is executed.
Because the TBLH register a read/write register and can be restored, care should be taken to ensure
its protection if both the main routine and Interrupt Service Routine use table read instructions. If
using the table read instructions, the Interrupt Service Routines may change the value of the TBLH
and subsequently cause errors if used again by the main routine. As a rule it is recommended that
simultaneous use of the table read instructions should be avoided. However, in situations where
simultaneous use cannot be avoided, the interrupts should be disabled prior to the execution of any
main routine table-read instructions. Note that all table related instructions require two instruction
cycles to complete their operation.
Rev. 1.00
22
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Table Read Program Example
tempreg1 db ? ; temporary register #1
tempreg2 db ? ; temporary register #2
:
:
mov a,06h ; initialise low table pointer - note that this address is referenced
mov tblp,a ; to the last page
:
:
tabrdl tempreg1 ; transfers value in table referenced by table pointer data at program
; memory address “F06H” transferred to tempreg1 and TBLH
dec tblp ; reduce value of table pointer by one
tabrdl tempreg2 ; transfers value in table referenced by table pointer
; data at program memory address “F05H” transferred to
; tempreg2 and TBLH
; in this example the data “1AH” is transferred to tempreg1 and data “0FH”
; to register tempreg2
:
:
org F00h; sets initial address of program memory
dc 00Ah, 00Bh, 00Ch, 00Dh, 00Eh, 00Fh, 01Ah, 01Bh
:
:
In Circuit Programming
The provision of Flash type Program Memory provides the user with a means of convenient and easy
upgrades and modifications to their programs on the same device. As an additional convenience,
Holtek has provided a means of programming the microcontroller in-circuit using a 4-pin interface.
This provides manufacturers with the possibility of manufacturing their circuit boards complete with
a programmed or un-programmed microcontroller, and then programming or upgrading the program
at a later stage. This enables product manufacturers to easily keep their manufactured products
supplied with the latest program releases without removal and re-insertion of the device.
The Holtek Flash MCU to Writer Programming Pin correspondence table is as follows:
Holtek Write Pins
MCU Programming Pins
ICPDA
PD0
Programming Serial Data
Function
ICPCK
PB4
Programming Serial Clock
VDD
VDD
Power Supply
VSS
VSS
Ground
The Program Memory and EEPROM data memory can both be programmed serially in-circuit using
this 4-wire interface. Data is downloaded and uploaded serially on a single pin with an additional
line for the clock. Two additional lines are required for the power supply and ground. The technical
details regarding the in-circuit programming of the device are beyond the scope of this document
and will be supplied in supplementary literature.
During the programming process, the user must take care to ensure that no other outputs are
connected to the PD0 and PB4 pins.
Rev. 1.00
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A/D 8-Bit Flash MCU with EEPROM
  Note: * may be resistor or capacitor. The resistance of * must be greater than 1k or the capacitance
of * must be less than 1nF.
On-Chip Debug Support – OCDS
There is an EV chip, HT66V488/489, which is used to emulate the HT66F488/HT66F489 device.
This EV chip device also provides an “On-Chip Debug” function to debug the device during the
development process. The EV chip and the actual MCU devices are almost functionally compatible
except for the “On-Chip Debug” function. Users can use the EV chip device to emulate the real chip
device behavior by connecting the OCDSDA and OCDSCK pins to the Holtek HT-IDE development
tools. The OCDSDA pin is the OCDS Data/Address input/output pin while the OCDSCK pin is the
OCDS clock input pin. When users use the EV chip for debugging, other functions which are shared
with the OCDSDA and OCDSCK pins in the actual MCU device will have no effect in the EV chip.
For a more detailed OCDS description, refer to the corresponding document named “Holtek e-Link
for 8-bit MCU OCDS User’s Guide”.
Rev. 1.00
Holtek e-Link Pins
EV Chip Pins
OCDSDA
OCDSDA
OCDS Data/Address input/output
OCDSCK
OCDSCK
OCDS Clock input
VDD
VDD
Power Supply
GND
VSS
Ground
24
Pin Description
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
RAM Data Memory
The Data Memory is an 8-bit wide RAM internal memory and is the location where temporary
information is stored.
Divided into two types, the first of Data Memory is an area of RAM where special function registers
are located. These registers have fixed locations and are necessary for correct operation of the
device. Many of these registers can be read from and written to directly under program control,
however, some remain protected from user manipulation. The second area of Data Memory is
reserved for general purpose use. All locations within this area are read and write accessible under
program control.
Structure
The Data Memory is divided into several sectors, all of which are implemented in 8-bit wide
Memory. Each of the Data Memory sectors is categorized into two types, the Special Purpose Data
Memory and the General Purpose Data Memory.
The start address of the Special Purpose Data Memory for all devices is the address 00H while the
start address of the General Purpose Data Memory is the address 80H. The Special Purpose Data
Memory registers are accessible in all sectors, with the exception of the EEC register at address
40H, which is only accessible in Sector 1.
Device
HT66F488
HT66F489
Capacity
Sectors
General Purpose: 384×8
0: 80H~FFH
1: 80H~FFH
2: 80H~FFH
00H
Sector 0
Special
Purpose
Data Memory
40H in sector 1
7FH
80H
General
Purpose
Data Memory
FFH
Sector 0
Sector 1
Sector 2
Data Memory Structure
General Purpose Data Memory
There are 384 bytes of general purpose memory which are arranged in 80H~FFH of Sector 0~Sector
2. All microcontroller programs require an area of read/write memory where temporary data can be
stored and retrieved for use later. It is this area of RAM memory that is known as General Purpose
Data Memory. The general purpose data memory is fully accessible by the user program for both
read and writing operations. By using the "SET [m].i" and "CLR [m].i" instructions individual
bits can be set or reset under program control giving the user a large range of flexibility for bit
manipulation in the Data Memory.
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A/D 8-Bit Flash MCU with EEPROM
Special Purpose Data Memory
This area of Data Memory is where registers, necessary for the correct operation of the
microcontroller, are stored. They are overlapped in any sector. Most of the registers are both
readable and writable but some are protected and are readable only, the details of which are located
under the relevant Special Function Register section. Note that for locations that are unused before
80H, any read instruction to these addresses will return the value "00H".
00H
01H
0�H
03H
0�H
0�H
06H
07H
08H
09H
0AH
0BH
0CH
0DH
0EH
0FH
10H
11H
1�H
13H
1�H
1�H
16H
17H
18H
19H
1AH
1BH
1CH
1DH
1EH
1FH
�0H
�1H
��H
�3H
��H
��H
�6H
�7H
�8H
�9H
�AH
�BH
�CH
�DH
�EH
�FH
30H
31H
3�H
33H
3�H
3�H
36H
37H
38H
39H
3AH
3BH
3CH
3DH
3EH
3FH
�ecto� 0~�
IAR0
MP0
IAR1
MP1L
MP1H
ACC
PCL
TBLP
TBLH
TBHP
�TATU�
�MOD
IAR�
MP�L
MP�H
Unused
INTC0
INTC1
INTC�
INTC3
MFI0
MFI1
MFI�
Unused
PAWU
PAPU
PA
PAC
PBPU
PB
PBC
PCPU
PC
PCC
PDPU
PD
PDC
IOHR0
IOHR1
Unused
ADRL
ADRH
ADCR0
ADCR1
ACERL
TMPC0
CTMC0
CTMC1
CTMDL
CTMDH
CTMAL
CTMAH
�TMC0
�TMC1
�TMDL
�TMDH
�TMAL
�TMAH
�TMRP
�IMTOC
�IMC0
�IMC1
�IMD
�IMC�/�IMA
�ecto� 0� � �ecto� 1
EEC
�0H Unused
�1H
EEA
��H
EED
�3H
PTM0C0
��H
PTM0C1
PTM0DL
��H
�6H
PTM0DH
�7H
PTM0AL
�8H
PTM0AH
�9H
PTM0RPL
PTM0RPH
�AH
�BH
PTM1C0
�CH
PTM1C1
�DH
PTM1DL
�EH
PTM1DH
PTM1AL
�FH
�0H
PTM1AH
PTM1RPL
�1H
��H
PTM1RPH
�3H
INTEG0
��H
INTEG1
��H
WDTC
�6H
TBC
�7H
CTRL
�8H
LVRC
�9H
LVDC
Unused
�AH
�BH
U�R
�CH
UCR1
�DH
UCR�
�EH
BRG
�FH
TXR/RXR
60H
�LCDC0
61H
�LCDC1
�LCDC�
6�H
63H
�LCDC3
6�H
�LCDC�
6�H
Unused
66H
Unused
67H
Unused
68H
IOHR�
69H
IOHR3
6AH
Unused
6BH
Unused
Unused
6CH
6DH
Unused
Unused
6EH
Unused
6FH
70H
Unused
71H
Unused
7�H
Unused
73H
Unused
7�H
Unused
7�H
Unused
76H
Unused
77H
Unused
78H
Unused
79H
Unused
7AH
Unused
7BH
Unused
7CH
Unused
7DH
Unused
7EH
Unused
7FH
Unused
: Unused� �ead as 00H
Special Purpose Data Memory
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A/D 8-Bit Flash MCU with EEPROM
Special Function Register Description
Most of the Special Function Register details will be described in the relevant functional sections,
however several registers require a separate description in this section.
Indirect Addressing Register – IAR0, IAR1, IAR2
The Indirect Addressing Registers, IAR0, IAR1 and IAR2, although having their locations in normal
RAM register space, do not actually physically exist as normal registers. The method of indirect
addressing for RAM data manipulation uses these Indirect Addressing Registers and Memory
Pointers, in contrast to direct memory addressing, where the actual memory address is specified.
Actions on the IAR0, IAR1 and IAR2 registers will result in no actual read or write operation to
these registers but rather to the memory location specified by their corresponding Memory Pointers,
MP0, MP1L/MP1H or MP2L/MP2H. Acting as a pair, IAR0 and MP0 can together access data
only from Sector 0 while the IAR1 register together with MP1L/MP1H register pair and IAR2
register together with MP2L/MP2H register pair can access data from any Data Memory sector. As
the Indirect Addressing Registers are not physically implemented, reading the Indirect Addressing
Registers indirectly will return a result of “00H” and writing to the registers indirectly will result in
no operation.
Memory Pointers – MP0, MP1L, MP1H, MP2L, MP2H
Five Memory Pointers, known as MP0, MP1L, MP1H, MP2L and MP2H, are provided. These
Memory Pointers are physically implemented in the Data Memory and can be manipulated in the
same way as normal registers providing a convenient way with which to address and track data.
When any operation to the relevant Indirect Addressing Registers is carried out, the actual address
that the microcontroller is directed to is the address specified by the related Memory Pointer. MP0,
together with Indirect Addressing Register, IAR0, are used to access data from Sector 0, while
MP1L/MP1H together with IAR1 and MP2L/MP2H together with IAR2 are used to access data
from all data sectors according to the corresponding MP1H or MP2H register. Direct Addressing can
be used in all data sectors using the corresponding instruction which can address all available data
memory space.
The following example shows how to clear a sector of four Data Memory locations already defined
as locations adres1 to adres4.
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A/D 8-Bit Flash MCU with EEPROM
Indirect Addressing Program Example 1
data.section ‘data’
adres1 db?
adres2 db?
adres3 db?
adres4 db?
block db?
code.section at 0 code
org 00h
start:
mov a, 04h;
mov block, a
mov a, offset adres1 ;
mov mp0, a ;
loop:
clr IAR0 ;
inc mp0;
sdz block;
jmp loop
continue:
setup size of block
Accumulator loaded with first RAM address
setup memory pointer with first RAM address
clear the data at address defined by MP0
increment memory pointer
check if last memory location has been cleared
Indirect Addressing Program Example 2
data .section at 01F0H ´data´
adres1 db ?
adres2 db ?
adres3 db ?
adres4 db ?
block db ?
code .section at 0 ´code´
org00h
start:
mov a,04h;
mov block,a
mov a, 01h;
mov mp1h, a
mov a,offset adres1 ;
mov mp1l,a ;
loop:
clr IAR1 ;
inc mp1l ;
sdz block ;
jmp loop
continue:
setup size of block
setup the memory sector
Accumulator loaded with first RAM address
setup memory pointer with first RAM address
clear the data at address defined by MP1L
increment memory pointer MP1L
check if last memory location has been cleared
The important point to note here is that in the example shown above, no reference is made to specific
Data Memory addresses.
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Accumulator – ACC
The Accumulator is central to the operation of any microcontroller and is closely related with
operations carried out by the ALU. The Accumulator is the place where all intermediate results
from the ALU are stored. Without the Accumulator it would be necessary to write the result of
each calculation or logical operation such as addition, subtraction, shift, etc., to the Data Memory
resulting in higher programming and timing overheads. Data transfer operations usually involve
the temporary storage function of the Accumulator; for example, when transferring data between
one user-defined register and another, it is necessary to do this by passing the data through the
Accumulator as no direct transfer between two registers is permitted.
Program Counter Low Register – PCL
To provide additional program control functions, the low byte of the Program Counter is made
accessible to programmers by locating it within the Special Purpose area of the Data Memory. By
manipulating this register, direct jumps to other program locations are easily implemented. Loading
a value directly into this PCL register will cause a jump to the specified Program Memory location,
however, as the register is only 8-bit wide, only jumps within the current Program Memory page are
permitted. When such operations are used, note that a dummy cycle will be inserted.
Look-up Table Registers – TBLP, TBHP, TBLH
These three special function registers are used to control operation of the look-up table which is
stored in the Program Memory. TBLP and TBHP are the table pointers and indicate the location
where the table data is located. Their value must be setup before any table read commands are
executed. Their value can be changed, for example using the “INC” or “DEC” instructions, allowing
for easy table data pointing and reading. TBLH is the location where the high order byte of the table
data is stored after a table read data instruction has been executed. Note that the lower order table
data byte is transferred to a user defined location.
Status Register – STATUS
This 8-bit register contains the SC flag, CZ flag, zero flag (Z), carry flag (C), auxiliary carry flag (AC),
overflow flag (OV), power down flag (PDF), and watchdog time-out flag (TO). These arithmetic/
logical operation and system management flags are used to record the status and operation of the
microcontroller.
With the exception of the TO and PDF flags, bits in the status register can be altered by instructions
like most other registers. Any data written into the status register will not change the TO or PDF flag.
In addition, operations related to the status register may give different results due to the different
instruction operations. The TO flag can be affected only by a system power-up, a WDT time-out or
by executing the “CLR WDT” or “HALT” instruction. The PDF flag is affected only by executing
the “HALT” or “CLR WDT” instruction or during a system power-up.
The Z, OV, AC, C, SC and CZ flags generally reflect the status of the latest operations.
• SC is the result of the “XOR” operation which is performed by the OV flag and the MSB of the
current instruction operation result.
• CZ is the operational result of different flags for different instuctions. Refer to register definitions
for more details.
• C is set if an operation results in a carry during an addition operation or if a borrow does not take
place during a subtraction operation; otherwise C is cleared. C is also affected by a rotate through
carry instruction.
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A/D 8-Bit Flash MCU with EEPROM
• AC is set if an operation results in a carry out of the low nibbles in addition, or no borrow from
the high nibble into the low nibble in subtraction; otherwise AC is cleared.
• Z is set if the result of an arithmetic or logical operation is zero; otherwise Z is cleared.
• OV is set if an operation results in a carry into the highest-order bit but not a carry out of the
highest-order bit, or vice versa; otherwise OV is cleared.
• PDF is cleared by a system power-up or executing the “CLR WDT” instruction. PDF is set by
executing the “HALT” instruction.
• TO is cleared by a system power-up or executing the “CLR WDT” or “HALT” instruction. TO is
set by a WDT time-out.
In addition, on entering an interrupt sequence or executing a subroutine call, the status register will
not be pushed onto the stack automatically. If the contents of the status registers are important and if
the subroutine can corrupt the status register, precautions must be taken to correctly save it.
STATUS Register
Bit
7
6
5
4
3
2
1
0
Name
SC
CZ
TO
PDF
OV
Z
AC
C
R/W
R/W
R/W
R
R
R/W
R/W
R/W
R/W
POR
x
x
0
0
x
x
x
x
“x” unknown
Bit 7SC: The result of the “XOR” operation which is performed by the OV flag and the
MSB of the instruction operation result.
Bit 6CZ: The the operational result of different flags for different instructions.
For SUB/SUBM/LSUB/LSUBM instructions, the CZ flag is equal to the Z flag.
For SBC/SBCM/LSBC/LSBCM instructions, the CZ flag is the “AND” operation
result which is performed by the previous operation CZ flag and current operation zero
flag.
For other instructions, the CZ flag will not be affected.
Bit 5TO: Watchdog Time-Out flag
0: After power up or executing the “CLR WDT” or “HALT” instruction
1: A watchdog time-out occurred.
Bit 4PDF: Power down flag
0: After power up or executing the “CLR WDT” instruction
1: By executing the “HALT” instruction
Bit 3OV: Overflow flag
0: No overflow
1: An operation results in a carry into the highest-order bit but not a carry out of the
highest-order bit or vice versa.
Bit 2Z: Zero flag
0: The result of an arithmetic or logical operation is not zero
1: The result of an arithmetic or logical operation is zero
Bit 1AC: Auxiliary flag
0: No auxiliary carry
1: An operation results in a carry out of the low nibbles in addition, or no borrow
from the high nibble into the low nibble in subtraction
Bit 0C: Carry flag
0: No carry-out
1: An operation results in a carry during an addition operation or if a borrow does
not take place during a subtraction operation
C is also affected by a rotate through carry instruction.
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A/D 8-Bit Flash MCU with EEPROM
EEPROM Data Memory
One of the special features in the device is its internal EEPROM Data Memory. EEPROM, which
stands for Electrically Erasable Programmable Read Only Memory, is by its nature a non-volatile
form of memory, with data retention even when its power supply is removed. By incorporating
this kind of data memory, a whole new host of application possibilities are made available to the
designer. The availability of EEPROM storage allows information such as product identification
numbers, calibration values, specific user data, system setup data or other product information to
be stored directly within the product microcontroller. The process of reading and writing data to the
EEPROM memory has been reduced to a very trivial affair.
EEPROM Data Memory Structure
The EEPROM Data Memory capacity is 64×8 bits for the device. Unlike the Program Memory
and RAM Data Memory, the EEPROM Data Memory is not directly mapped into memory space
and is therefore not directly addressable in the same way as the other types of memory. Read and
Write operations to the EEPROM are carried out in single byte operations using an address and data
register in Sector 0 and a single control register in Sector 1.
EEPROM Registers
Three registers control the overall operation of the internal EEPROM Data Memory. These are the
address register, EEA, the data register, EED and a single control register, EEC. As both the EEA
and EED registers are located in all sectors, they can be directly accessed in the same was as any
other Special Function Register. The EEC register however, being located in Sector 1, cannot be
directly addressed directly and can only be read from or written to indirectly using the MP1L/MP1H
or MP2L/MP2H Memory Pointer and Indirect Addressing Register, IAR1 or IAR2. Because the
EEC control register is located at address 40H in Sector 1, the MP1L or MP2L Memory Pointer low
byte must first be set to the value 40H and the MP1H or MP2H Memory Pointer high byte set to the
value 01H before any operations on the EEC register are executed.
Register
Name
Bit
7
6
5
4
3
2
1
0
EEA
—
—
D5
D4
D3
D2
D1
D0
EED
D7
D6
D5
D4
D3
D2
D1
D0
EEC
—
—
—
—
WREN
WR
RDEN
RD
EEPROM Control Registers List
EEA Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
D5
D4
D3
D2
D1
D0
R/W
—
—
R/W
R/W
R/W
R/W
R/W
R/W
POR
—
—
0
0
0
0
0
0
Bit 7~6
Unimplemented, read as “0”
Bit 5~0D5~D0: Data EEPROM address
Data EEPROM address bit 5 ~ bit 0
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EED Register
Bit
7
6
5
4
3
2
1
0
Name
D7
D6
D5
D4
D3
D2
D1
D0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7~0D7~D0: Data EEPROM data
Data EEPROM data bit 7 ~ bit 0
EEC Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
WREN
WR
RDEN
RD
R/W
—
—
—
—
R/W
R/W
R/W
R/W
POR
—
—
—
—
0
0
0
0
Bit 7~4
Unimplemented, read as “0”
Bit 3WREN: Data EEPROM Write Enable
0: Disable
1: Enable
This is the Data EEPROM Write Enable Bit which must be set high before Data
EEPROM write operations are carried out. Clearing this bit to zero will inhibit Data
EEPROM write operations.
Bit 2WR: EEPROM Write Control
0: Write cycle has finished
1: Activate a write cycle
This is the Data EEPROM Write Control Bit and when set high by the application
program will activate a write cycle. This bit will be automatically reset to zero by the
hardware after the write cycle has finished. Setting this bit high will have no effect if
the WREN has not first been set high.
Bit 1RDEN: Data EEPROM Read Enable
0: Disable
1: Enable
This is the Data EEPROM Read Enable Bit which must be set high before Data
EEPROM read operations are carried out. Clearing this bit to zero will inhibit Data
EEPROM read operations.
Bit 0RD: EEPROM Read Control
0: Read cycle has finished
1: Activate a read cycle
This is the Data EEPROM Read Control Bit and when set high by the application
program will activate a read cycle. This bit will be automatically reset to zero by the
hardware after the read cycle has finished. Setting this bit high will have no effect if
the RDEN has not first been set high.
Note: The WREN, WR, RDEN and RD can not be set to “1” at the same time in one instruction. The
WR and RD can not be set to “1” at the same time.
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A/D 8-Bit Flash MCU with EEPROM
Reading Data from the EEPROM
To read data from the EEPROM, the read enable bit, RDEN, in the EEC register must first be set
high to enable the read function. The EEPROM address of the data to be read must then be placed
in the EEA register. If the RD bit in the EEC register is now set high, a read cycle will be initiated.
Setting the RD bit high will not initiate a read operation if the RDEN bit has not been set. When
the read cycle terminates, the RD bit will be automatically cleared to zero, after which the data can
be read from the EED register. The data will remain in the EED register until another read or write
operation is executed. The application program can poll the RD bit to determine when the data is
valid for reading.
Writing Data to the EEPROM
The EEPROM address of the data to be written must first be placed in the EEA register and the data
placed in the EED register. To write data to the EEPROM, the write enable bit, WREN, in the EEC
register must first be set high to enable the write function. After this, the WR bit in the EEC register
must be immediately set high to initiate a write cycle. These two instructions must be executed
consecutively. The global interrupt bit EMI should also first be cleared before implementing any
write operations, and then set again after the write cycle has started. Setting the WR bit high will not
initiate a write cycle if the WREN bit has not been set. As the EEPROM write cycle is controlled
using an internal timer whose operation is asynchronous to microcontroller system clock, a certain
time will elapse before the data will have been written into the EEPROM. Detecting when the write
cycle has finished can be implemented either by polling the WR bit in the EEC register or by using
the EEPROM interrupt. When the write cycle terminates, the WR bit will be automatically cleared
to zero by the microcontroller, informing the user that the data has been written to the EEPROM.
The application program can therefore poll the WR bit to determine when the write cycle has ended.
Write Protection
Protection against inadvertent write operation is provided in several ways. After the device is
powered-on the Write Enable bit in the control register will be cleared preventing any write
operations. Also at power-on MP1L/MP1H and MP2L/MP2H will be reset to zero, which means
that Data Memory Sector 0 will be selected. As the EEPROM control register is located in Sector 1,
this adds a further measure of protection against spurious write operations. During normal program
operation, ensuring that the Write Enable bit in the control register is cleared will safeguard against
incorrect write operations.
EEPROM Interrupt
The EEPROM write interrupt is generated when an EEPROM write cycle has ended. The EEPROM
interrupt must first be enabled by setting the DEE bit in the relevant interrupt register. When an
EEPROM write cycle ends, the DEF request flag will be set. If the global and EEPROM interrupts
are enabled and the stack is not full, a jump to the associated Interrupt vector will take place. When
the interrupt is serviced the EEPROM interrupt flag will be automatically reset. More details can be
obtained in the Interrupt section.
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Programming Considerations
Care must be taken that data is not inadvertently written to the EEPROM. Protection can be Periodic
by ensuring that the Write Enable bit is normally cleared to zero when not writing. Also the Bank
Pointer could be normally cleared to zero as this would inhibit access to Bank 1where the EEPROM
control register exist. Although certainly not necessary, consideration might be given in the
application program to the checking of the validity of new write data by a simple read back process.
When writing data the WR bit must be set high immediately after the WREN bit has been set high,
to ensure the write cycle executes correctly. The global interrupt bit EMI should also be cleared
before a write cycle is executed and then re-enabled after the write cycle starts. Note that the device
should not enter the IDLE or SLEEP mode until the EEPROM read or write operation is totally
complete. Otherwise, the EEPROM read or write operation will fail.
Programming Examples
Reading data from the EEPROM - polling method
MOV A, EEPROM_ADRES MOV EEA, A
MOV A, 040H
MOV MP1L, A
MOV A, 01H
MOV MP1H, A
SET IAR1.1
SET IAR1.0 BACK:
SZ IAR1.0
JMP BACK
CLR IAR1
CLR BP
MOV A, EED
MOV READ_DATA, A
; user defined address
; setup memory pointer MP1L
; MP1 points to EEC register
; setup memory pointer MP1H
; set RDEN bit, enable read operations
; start Read Cycle - set RD bit
; check for read cycle end
; disable EEPROM read/write
; move read data to register
Writing Data to the EEPROM - polling method
MOV A, EEPROM_ADRES
MOV EEA, A
MOV A, EEPROM_DATA
MOV EED, A
MOV A, 040H
MOV MP1L, A
MOV A, 01H
MOV MP1H, A
CLR EMI
SET IAR1.3
SET IAR1.2
SET EMI
BACK:
SZ IAR1.2
JMP BACK
CLR IAR1
CLR MP1H
Rev. 1.00
; user defined address
; user defined data
; setup memory pointer MP1L
; MP1 points to EEC register
; setup memory pointer MP1H
;
;
;
;
diable global interrupt
set WREN bit, enable write operations
start Write Cycle - set WR bit
enable global interrupt
; check for write cycle end
; disable EEPROM write
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A/D 8-Bit Flash MCU with EEPROM
Oscillator
Various oscillator options offer the user a wide range of functions according to their various
application requirements. The flexible features of the oscillator functions ensure that the best
optimisation can be achieved in terms of speed and power saving. Oscillator selections and operation
are selected through a combination of configuration options and registers.
Oscillator Overview
In addition to being the source of the main system clock the oscillators also provide clock sources
for the Watchdog Timer and Time Base Interrupts. The external oscillators requiring some external
components as well as fully integrated internal oscillators requiring no external components are
provided to form a wide range of both fast and slow system oscillators. All oscillator options
are selected through the configuration options. The higher frequency oscillator provides higher
performance but carry with it the disadvantage of higher power requirements, while the opposite
is of course true for the lower frequency oscillators. With the capability of dynamically switching
between fast and slow system clock, the device has the flexibility to optimize the performance/
power ratio, a feature especially important in power sensitive portable applications.
Name
Freq.
Pins
External Crystal
Type
HXT
400kHz~20MHz
OSC1/OSC2
Internal High Speed RC
HIRC
8MHz
—
External low speed Crystal
LXT
32.768kHz
XT1/XT2
Internal Low Speed RC
LIRC
32kHz
—
Oscillator Types
System Clock Configurations
There are four methods of generating the system clock, two high speed oscillators and two low speed
oscillators. The high speed oscillators are the external crystal oscillator and the internal 8MHz RC
oscillator. The low speed oscillators are the external 32.768kHz crystal oscillator and internal 32kHz
RC oscillator. Selecting whether the low or high speed oscillator is used as the system oscillator is
implemented using the HLCLK bit and CKS2 ~ CKS0 bits in the SMOD register and as the system
clock can be dynamically selected.
The actual source clock used for each of the high speed and the low speed oscillators is chosen
via configuration options. The frequency of the slow speed or high speed system clock is also
determined using the HLCLK bit and CKS2 ~ CKS0 bits in the SMOD register. Note that two
oscillator selections must be made namely one high speed and one low speed system oscillators. It is
not possible to choose a no-oscillator selection for either the high or low speed oscillator.
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A/D 8-Bit Flash MCU with EEPROM
High Speed Oscillators
HXT
fH
6-stage Prescaler
HIRC
fH/2
fH/4
High Speed Oscillator
Configuration Option
fH/8
fH/16
Low Speed Oscillators
LXT
fH/32
fH/64
fL
fL
fSYS
LIRC
fSUB
Low Speed Oscillator
Configuration Option
HLCLK,
CKS2~CKS0 bits
Fast Wake-up from SLEEP Mode or
IDLE Mode Control (for HXT only)
Note: The OSC1/XT1 and OSC2/XT2 share the same pins, so the HXT oscillator and the LXT
oscillator can not be selected at the same time.
System Clock Configurations
External Crystal/Ceramic Oscillator – HXT
The External Crystal/Ceramic System Oscillator is one of the high frequency oscillator choices,
which is selected via configuration option. For most crystal oscillator configurations, the simple
connection of a crystal across OSC1 and OSC2 will create the necessary phase shift and feedback for
oscillation, without requiring external capacitors. However, for some crystal types and frequencies,
to ensure oscillation, it may be necessary to add two small value capacitors, C1 and C2. Using a
ceramic resonator will usually require two small value capacitors, C1 and C2, to be connected as
shown for oscillation to occur. The values of C1 and C2 should be selected in consultation with the
crystal or resonator manufacturer’s specification.
For oscillator stability and to minimise the effects of noise and crosstalk, it is important to ensure
that the crystal and any associated resistors and capacitors along with interconnecting lines are all
located as close to the MCU as possible.
   Crystal/Resonator Oscillator – HXT
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Crystal Oscillator C1 and C2 Values
Crystal Frequency
C1
C2
12MHz
0pF
0pF
8MHz
0pF
0pF
4MHz
0pF
0pF
1MHz
100pF
100pF
Note: C1 and C2 values are for guidance only.
Crystal Recommended Capacitor Values
Internal RC Oscillator – HIRC
The internal RC oscillator is a fully integrated system oscillator requiring no external components.
The internal RC oscillator has a fixed frequency of 8MHz. Device trimming during the
manufacturing process and the inclusion of internal frequency compensation circuits are used to
ensure that the influence of the power supply voltage, temperature and process variations on the
oscillation frequency are minimised. As a result, at a power supply of 5V and at temperature of 25°C
degrees, the fixed oscillation frequency of the HIRC will have a tolerance within 2%. PB3 and PB4
can be used as normal I/O pins.
External 32.768kHz Crystal Oscillator – LXT
The External 32.768kHz Crystal System Oscillator is one of the low frequency oscillator choices,
which is selected via configuration option. This clock source has a fixed frequency of 32.768kHz
and requires a 32.768kHz crystal to be connected between pins XT1 and XT2. The external resistor
and capacitor components connected to the 32.768kHz crystal are necessary to provide oscillation.
For applications where precise frequencies are essential, these components may be required to
provide frequency compensation due to different crystal manufacturing tolerances. During power-up
there is a time delay associated with the LXT oscillator waiting for it to start-up.
When the microcontroller enters the SLEEP or IDLE Mode, the system clock is switched off to stop
microcontroller activity and to conserve power. However, in many microcontroller applications
it may be necessary to keep the internal timers operational even when the microcontroller is in
the SLEEP or IDLE Mode. To do this, another clock, independent of the system clock, must be
provided.
However, for some crystals, to ensure oscillation and accurate frequency generation, it is necessary
to add two small value external capacitors, C1 and C2. The exact values of C1 and C2 should
be selected in consultation with the crystal or resonator manufacturer specification. The external
parallel feedback resistor, Rp, is required.
Some configuration options determine if the XT1/XT2 pins are used for the LXT/HXT oscillator or
as I/O pins.
• If the LXT oscillator is not used for any clock source, the XT1/XT2 pins can be used as normal I/
O pins or HXT oscillator.
• If the LXT oscillator is used for any clock source, the 32.768kHz crystal should be connected to
the XT1/XT2 pins.
For oscillator stability and to minimise the effects of noise and crosstalk, it is important to ensure
that the crystal and any associated resistors and capacitors along with interconnecting lines are all
located as close to the MCU as possible.
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A/D 8-Bit Flash MCU with EEPROM
­   
   ­ External LXT Oscillator
LXT Oscillator C1 and C2 Values
Crystal Frequency
C1
C2
32.768kHz
10pF
10pF
Note: 1. C1 and C2 values are for guidance only.
2. RP=5MΩ~10MΩ is recommended.
32.768kHz Crystal Recommended Capacitor Values
LXT Oscillator Low Power Function
The LXT oscillator can function in one of two modes, the Quick Start Mode and the Low Power
Mode. The mode selection is executed using the LXTLP bit in the TBC register.
LXTLP
LXT Mode
0
Quick Start Mode
1
Low Power Mode
After power on, the LXTLP bit will be automatically cleared to zero ensuring that the LXT oscillator
is in the Quick Start operating mode. In the Quick Start Mode the LXT oscillator will power up
and stabilise quickly. However, after the LXT oscillator has fully powered up it can be placed
into the Low-power mode by setting the LXTLP bit high. The oscillator will continue to run but
with reduced current consumption, as the higher current consumption is only required during the
LXT oscillator start-up. In power sensitive applications, such as battery applications, where power
consumption must be kept to a minimum, it is therefore recommended that the application program
sets the LXTLP bit high about 2 seconds after power-on.
It should be noted that, no matter what condition the LXTLP bit is set to, the LXT oscillator will
always function normally, the only difference is that it will take more time to start up if in the Lowpower mode.
Internal 32kHz Oscillator – LIRC
The Internal 32kHz System Oscillator is the low frequency oscillator. It is a fully integrated
RC oscillator with a typical frequency of 32kHz at 5V, requiring no external components for its
implementation. Device trimming during the manufacturing process and the inclusion of internal
frequency compensation circuits are used to ensure that the influence of the power supply voltage,
temperature and process variations on the oscillation frequency are minimised. As a result, at a
power supply of 5V and at a temperature of 25°C degrees, the fixed oscillation frequency of 32kHz
will have a tolerance within 10%.
Supplementary Oscillator
The low speed oscillator, in addition to providing a system clock source is also used to provide
a clock source to two other device functions. These are the Watchdog Timer and the Time Base
Interrupts.
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Operating Modes and System Clocks
Present day applications require that their microcontrollers have high performance but often still
demand that they consume as little power as possible, conflicting requirements that are especially
true in battery powered portable applications. The fast clocks required for high performance will
by their nature increase current consumption and of course vice-versa, lower speed clocks reduce
current consumption. As Holtek has provided this device with both high and low speed clock
sources and the means to switch between them dynamically, the user can optimise the operation of
their microcontroller to achieve the best performance/power ratio.
System Clocks
The device has many different clock sources for both the CPU and peripheral function operation.
By providing the user with a wide range of clock options using configuration options and register
programming, a clock system can be configured to obtain maximum application performance.
The main system clock, can come from either a high frequency, fH, or a low frequency, fL, and is
selected using the HLCLK bit and CKS2~CKS0 bits in the SMOD register. The high speed system
clock can be sourced from either an HXT or HIRC oscillator, selected via a configuration option.
The low speed system clock source can be sourced from internal clock fL. If fL is selected then it
can be sourced by either the LXT or LIRC oscillator, selected via a configuration option. The other
choice, which is a divided version of the high speed system oscillator has a range of fH/2~fH/64.
There are two additional internal clocks for the peripheral circuits, the substitute clock, fSUB, and
the Time Base clock, fTBC. Each of these internal clocks is sourced by the LIRC or LXT oscillator.
The fSUB clock is used to provide a substitute clock for the microcontroller just after a wake-up has
occurred to enable faster wake-up times. The fSUB is used for the Watchdog Timer while the fTBC
provides the clock for the Time base and TMs.
High Speed Oscillators
HXT
fH
6-stage Prescaler
HIRC
fH/2
fH/4
High Speed Oscillator
Configuration Option
fH/8
fH/16
Low Speed Oscillators
LXT
fH/32
fH/64
fL
fL
fSYS
LIRC
fSUB
Low Speed Oscillator
Configuration Option
HLCLK,
CKS2~CKS0 bits
Fast Wake-up from SLEEP Mode or
IDLE Mode Control (for HXT only)
fSUB
WDT
fTBC
fTB
fSYS/4
Time Base
TBCK
System Clock Configurations
Note: When the system clock source fSYS is switched to fL from fH, the high speed oscillation will
stop to conserve the power. Thus there is no fH~fH/64 for peripheral circuit to use.
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System Operation Modes
There are 6 different modes of operation for the microcontroller, each one with its own special
characteristics and which can be chosen according to the specific performance and power
requirements of the application. There are three modes allowing normal operation of the
microcontroller, the NORMAL, SLOW0 and SLOW1 Mode. The remaining three modes, the
SLEEP, IDLE0 and IDLE1 Modes are used when the microcontroller CPU is switched off to
conserve power.
Operating
Mode
Description
CPU
fSYS
fSUB
fTBC
NORMAL mode
On
fH~fH/64
On
On
SLOW0 mode
On
fL
On
On
SLOW1 mode
On
fH/2~fH/64
On
On
ILDE0 mode
Off
Off
On
On
IDLE1 mode
Off
On
On
On
SLEEP mode
Off
Off
On
Off
NORMAL Mode
As the name suggests this is one of the main operating modes where the microcontroller has all of
its functions operational and where the system clock is provided by one of the high speed oscillators.
This mode operates allowing the microcontroller to operate normally with a clock source will come
from one of the high speed oscillators, HXT or HIRC.
SLOW0 Mode
This is also a mode where the microcontroller operates normally although now with a slower speed
clock source. The clock source used will be from the low speed oscillator LIRC or LXT. Running
the microcontroller in this mode allows it to run with much lower operating currents. In the SLOW
Mode 0, the fH is off.
SLOW1 Mode
This is also a mode where the microcontroller operates normally although now with a slower speed
clock source. The high speed oscillator will however first be divided by a ratio ranging from 2 to 64,
the actual ratio being selected by the CKS2~CKS0 bits in the SMOD register. Although a high speed
oscillator is used, running the microcontroller at a divided clock ratio reduces the operating current.
SLEEP Mode
The SLEEP Mode is entered when an HALT instruction is executed and the IDLEN bit in the SMOD
register is low. In the SLEEP mode the CPU will be stopped. However the fSUB clock will continue
to operate as the Watchdog Timer clock.
IDLE0 Mode
The IDLE0 Mode is entered when a HALT instruction is executed and when the IDLEN bit in the
SMOD register is high and the FSYSON bit in the CTRL register is low. In the IDLE0 Mode the
system oscillator will be inhibited from driving the CPU but some peripheral functions will remain
operational such as the Watchdog Timer and TMs. In the IDLE0 Mode, the system oscillator will be
stopped.
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IDLE1 Mode
The IDLE1 Mode is entered when a HALT instruction is executed and when the IDLEN bit in the
SMOD register is high and the FSYSON bit in the CTRL register is high. In the IDLE1 Mode the
system oscillator will be inhibited from driving the CPU but may continue to provide a clock source
to keep some peripheral functions operational such as the Watchdog Timer and TMs. In the IDLE1
Mode, the system oscillator will continue to run, and this system oscillator may be high speed or low
speed system oscillator. In the IDLE1 Mode the Watchdog Timer clock, fSUB, will be on.
Control Register
A single register, SMOD, is used for overall control of the internal clocks within the device.
SMOD Register
Bit
7
6
5
4
3
2
1
0
Name
CKS2
CKS1
CKS0
FSTEN
LTO
HTO
IDLEN
HLCLK
R/W
R/W
R/W
R/W
R/W
R
R
R/W
R/W
POR
0
0
0
0
0
0
1
1
Bit 7 ~ 5
CKS2 ~ CKS0: The system clock selection bits when HLCLK=0
000: fL (LIRC or LXT)
001: fL (LIRC or LXT)
010: fH/64
011: fH/32
100: fH/16
101: fH/8
110: fH/4
111: fH/2
These three bits are used to select which clock is used as the system clock source. In
addition to the system clock source, which can be the LIRC or LXT, a divided version
of the high speed system oscillator can also be chosen as the system clock source.
Bit 4FSTEN: Fast Wake-up Control (only for HXT)
0: Disable
1: Enable
This is the Fast Wake-up Control bit which determines if the fSUB clock source is
initially used after the device wakes up. When the bit is high, the fSUB clock source can
be used as a temporary system clock to provide a faster wake up time as the fSUB clock
is available.
Bit 3LTO: Low speed system oscillator ready flag
0: Not ready
1: Ready
This is the low speed system oscillator ready flag which indicates when the low speed
system oscillator is stable after power on reset.
Bit 2HTO: High speed system oscillator ready flag
0: Not ready
1: Ready
This is the high speed system oscillator ready flag which indicates when the high speed
system oscillator is stable. This flag is cleared to “0” by hardware when the device is
powered on and then changes to a high level after the high speed system oscillator is
stable. Therefore this flag will always be read as “1” by the application program after
device power-on. The flag will be low when in the SLEEP, IDLE0 or SLOW0 Mode,
but after power on reset or a wake-up has occurred, the flag will change to a high level
after 128 clock cycles if the HXT oscillator is used and after 15~16 clock cycles if the
HIRC oscillator is used.
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A/D 8-Bit Flash MCU with EEPROM
Bit 1IDLEN: IDLE Mode Control
0: Disable
1: Enable
This is the IDLE Mode Control bit and determines what happens when the HALT
instruction is executed. If this bit is high, when a HALT instruction is executed the
device will enter the IDLE Mode. In the IDLE1 Mode the CPU will stop running
but the system clock will continue to keep the peripheral functions operational, if
FSYSON bit is high. If FSYSON bit is low, the CPU and the system clock will all stop
in IDLE0 mode. If the bit is low the device will enter the SLEEP Mode when a HALT
instruction is executed.
Bit 0HLCLK: System Clock Selection
0: fH/2 ~ fH/64 or fL
1: fH
This bit is used to select if the fH clock or the fH/2 ~ fH/64 or fL clock is used as the
system clock. When the bit is high the fH clock will be selected and if low the fH/2 ~
fH/64 or fL clock will be selected. When system clock switches from the fH clock to the
fL clock and the fH clock will be automatically switched off to conserve power.
CTRL Register
Bit
7
6
5
4
3
2
1
0
Name
FSYSON
—
—
—
—
LVRF
LRF
WRF
R/W
R/W
—
—
—
—
R/W
R/W
R/W
POR
0
—
—
—
—
0
0
0
Bit 7
FSYSON: fSYS Control IDLE Mode
0: Disable
1: Enable
Bit 6~ 3
Unimplemented, read as “0”
Bit 2LVRF: LVR function reset flag
Describe elsewhere
Bit 1LRF: LVRC register software reset flag
Describe elsewhere
Bit 0WRF: WDTC register software reset flag
Describe elsewhere
Fast Wake-up
To minimise power consumption the device can enter the SLEEP or IDLE0 Mode, where the system
clock source to the device will be stopped. However when the device is woken up again, it can take
a considerable time for the original system oscillator to restart, stabilise and allow normal operation
to resume. To ensure the device is up and running as fast as possible a Fast Wake-up function is
provided, which allows fSUB, to act as a temporary clock to first drive the system until the original
system oscillator has stabilised. The temporary clock is sourced by the LIRC or LXT oscillator. As
the clock source for the Fast Wake-up function is fSUB, the Fast Wake-up function is only available
in the SLEEP and IDLE0 modes. The Fast Wake-up enable/disable function is controlled using the
FSTEN bit in the SMOD register.
If the HXT oscillator is selected as the NORMAL Mode system clock, and if the Fast Wake-up
function is enabled, then it will take one to two tSUB clock cycles for the system to wake-up. The
system will then initially run under the fSUB clock source until 128 HXT clock cycles have elapsed,
at which point the HTO flag will switch high and the system will switch over to operating from the
HXT oscillator.
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A/D 8-Bit Flash MCU with EEPROM
If the HIRC oscillators or LIRC oscillator is used as the system oscillator then it will take 15~16
clock cycles or 1~2 cycles to wake up the system from the SLEEP or IDLE0 Mode. The Fast Wake-up
bit, FSTEN will have no effect in these cases.
System
Oscillator
FSTEN Bit
Wake-up Time
(SLEEP Mode)
Wake-up Time
(IDLE0 Mode)
Wake-up Time
(IDLE1 Mode)
0
128 HXT cycles
1~2 HXT cycles
1
1~2 fSUB cycles
(System runs with fSUB first for 128 HXT cycles and
then switches over to run with the HXT clock)
1~2 HXT cycles
HIRC
×
15~16 HIRC cycles
1~2 HIRC cycles
LIRC
×
1~2 LIRC cycles
1~2 LIRC cycles
LXT
×
128 LXT cycles
1~2 LXT cycles
HXT
Wake-up Times
Operating Mode Switching
The device can switch between operating modes dynamically allowing the user to select the best
performance/power ratio for the present task in hand. In this way microcontroller operations that
do not require high performance can be executed using slower clocks thus requiring less operating
current and prolonging battery life in portable applications.
In simple terms, Mode Switching between the NORMAL Mode and SLOW Mode is executed
using the HLCLK bit and CKS2~CKS0 bits in the SMOD register while Mode Switching from the
NORMAL/SLOW Modes to the SLEEP/IDLE Modes is executed via the HALT instruction. When
a HALT instruction is executed, whether the device enters the IDLE Mode or the SLEEP Mode is
determined by the condition of the IDLEN bit in the SMOD register and FSYSON in the CTRL
register.
When the HLCLK bit switches to a low level, which implies that clock source is switched from the
high speed clock source, fH, to the clock source, fH/2~fH/64 or fL. If the clock is from the fL, the high
speed clock source will stop running to conserve power. When this happens it must be noted that the
fH/16 and fH/64 internal clock sources will also stop running, which may affect the operation of other
internal functions such as the TMs. The accompanying flowchart shows what happens when the
device moves between the various operating modes.
NORMAL Mode to SLOW0 Mode Switching
When running in the NORMAL Mode, which uses the high speed system oscillator, and therefore
consumes more power, the system clock can switch to run in the SLOW0 Mode by setting the
HLCLK bit to “0” and setting the CKS2~CKS0 bits to “000” or “001” in the SMOD register.This
will then use the low speed system oscillator which will consume less power. Users may decide to
do this for certain operations which do not require high performance and can subsequently reduce
power consumption. The SLOW Mode is sourced from the LIRC or LXT oscillator and therefore
requires these oscillators to be stable before full mode switching occurs. This is monitored using the
LTO bit in the SMOD register.
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NORMAL Mode to SLOW1 Mode Switching
When running in the NORMAL Mode, which uses the high speed system oscillator, and therefore
consumes more power, the system clock can switch to run in the SLOW1 Mode by setting the
HLCLK bit to “0” and setting the CKS2~CKS0 bits to “010”, “011”, “100”, “101”, “110” or
“111” in the SMOD register.This will then use a divided clock of the high speed system oscillator
which can reduce the operating current. The SLOW1 Mode is still sourced from the HIRC or HXT
oscillator and therefore requires less time for full mode switching.
SLOW0 Mode to NORMAL Mode Switching
In SLOW0 Mode the system uses LIRC or LXT low speed system oscillator. To switch back to the
NORMAL Mode, where the high speed system oscillator is used, the HLCLK bit should be set to “1”.
As a certain amount of time will be required for the high frequency clock to stabilise, the status of
the HTO bit is checked. The amount of time required for high speed system oscillator stabilization
depends upon which high speed system oscillator type is used.
SLOW1 Mode to NORMAL Mode Switching
In SLOW1 Mode the system still uses high speed system oscillator. To switch back to the NORMAL
Mode, where also the high speed system oscillator is used, the HLCLK bit should be set to “1”. As
the two modes both use the high speed system oscillator, therefore requires less time for full mode
switching.
Entering the SLEEP Mode
There is only one way for the device to enter the SLEEP Mode and that is to execute the “HALT”
instruction in the application program with the IDLEN bit in SMOD register equal to “0” and the
WDT on. When this instruction is executed under the conditions described above, the following will
occur:
• The system clock and Time Base clock will be stopped and the application program will stop at
the “HALT” instruction, but the WDT will remain with the clock source coming from the fSUB
clock.
• The Data Memory contents and registers will maintain their present condition.
• The WDT will be cleared and resume counting.
• The I/O ports will maintain their present conditions.
• In the status register, the Power Down flag, PDF, will be set and the Watchdog time-out flag, TO,
will be cleared.
Entering the IDLE0 Mode
There is only one way for the device to enter the IDLE0 Mode and that is to execute the “HALT”
instruction in the application program with the IDLEN bit in SMOD register equal to “1” and the
FSYSON bit in CTRL register equal to “0”. When this instruction is executed under the conditions
described above, the following will occur:
• The system clock will be stopped and the application program will stop at the “HALT” instruction,
but the Time Base clock fTBC and the fSUB clock will be on.
• The Data Memory contents and registers will maintain their present condition.
• The WDT will be cleared and resume counting.
• The I/O ports will maintain their present conditions.
• In the status register, the Power Down flag, PDF, will be set and the Watchdog time-out flag, TO,
will be cleared.
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Entering the IDLE1 Mode
There is only one way for the device to enter the IDLE1 Mode and that is to execute the “HALT”
instruction in the application program with the IDLEN bit in SMOD register equal to “1” and the
FSYSON bit in CTRL register equal to “1”. When this instruction is executed under the conditions
described above, the following will occur:
• The system clock and Time Base clock and fSUB will be on and the application program will stop
at the “HALT” instruction.
• The Data Memory contents and registers will maintain their present condition.
• The WDT will be cleared and resume counting.
• The I/O ports will maintain their present conditions.
• In the status register, the Power Down flag, PDF, will be set and the Watchdog time-out flag, TO,
will be cleared.
Standby Current Considerations
As the main reason for entering the SLEEP or IDLE Mode is to keep the current consumption of the
device to as low a value as possible, perhaps only in the order of several micro-amps except in the
IDLE1 Mode, there are other considerations which must also be taken into account by the circuit
designer if the power consumption is to be minimised. Special attention must be made to the I/O pins
on the device. All high-impedance input pins must be connected to either a fixed high or low level as
any floating input pins could create internal oscillations and result in increased current consumption.
This also applies to devices which have different package types, as there may be unbonbed pins.
These must either be setup as outputs or if setup as inputs must have pull-high resistors connected.
Care must also be taken with the loads, which are connected to I/O pins, which are setup as
outputs. These should be placed in a condition in which minimum current is drawn or connected
only to external circuits that do not draw current, such as other CMOS inputs. In the IDLE1 Mode
the system oscillator is on, if the system oscillator is from the high speed system oscillator, the
additional standby current will also be perhaps in the order of several hundred micro-amps.
Wake-up
After the system enters the SLEEP or IDLE Mode, it can be woken up from one of various sources
listed as follows:
• An external falling edge on Port A
• A system interrupt
• A WDT overflow
If the device is woken up by a WDT overflow, a Watchdog Timer reset will be initiated. Although
both of these wake-up methods will initiate a reset operation, the actual source of the wake-up can
be determined by examining the TO and PDF flags. The PDF flag is cleared by a system power-up or
executing the clear Watchdog Timer instructions and is set when executing the “HALT” instruction.
The TO flag is set if a WDT time-out occurs, and causes a wake-up that only resets the Program
Counter and Stack Pointer, the other flags remain in their original status.
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A/D 8-Bit Flash MCU with EEPROM
Each pin on Port A can be setup using the PAWU register to permit a negative transition on the pin
to wake-up the system. When a Port A pin wake-up occurs, the program will resume execution at
the instruction following the “HALT” instruction. If the system is woken up by an interrupt, then
two possible situations may occur. The first is where the related interrupt is disabled or the interrupt
is enabled but the stack is full, in which case the program will resume execution at the instruction
following the “HALT” instruction. In this situation, the interrupt which woke-up the device will not
be immediately serviced, but will rather be serviced later when the related interrupt is finally enabled
or when a stack level becomes free. The other situation is where the related interrupt is enabled and
the stack is not full, in which case the regular interrupt response takes place. If an interrupt request
flag is set high before entering the SLEEP or IDLE Mode, the wake-up function of the related
interrupt will be disabled.
Programming Considerations
The high speed and low speed oscillators both use the same SST counter. For example, if the system
is woken up from the SLEEP Mode and the HIRC oscillators need to start-up from an off state.
• If the device is woken up from the SLEEP Mode to NORMAL Mode, and the system clock
source is from HXT oscillator and FSTEN is “1”, the system clock can be switched to the LIRC
or LXT oscillator after wake up.
• There are peripheral functions, such as TMs, for which the fSYS is used. If the system clock source
is switched from fH to fL, the clock source to the peripheral functions mentioned above will
change accordingly.
Watchdog Timer
The Watchdog Timer is provided to prevent program malfunctions or sequences from jumping to
unknown locations, due to certain uncontrollable external events such as electrical noise.
Watchdog Timer Clock Source
The Watchdog Timer clock source is provided by the fSUB clock. The fSUB clock can be sourced from
either the LIRC or LXT oscillator selected by a configuration option. The LIRC internal oscillator
has an approximate frequency of 32kHz and this specified internal clock period can vary with VDD,
temperature and process variations. The LXT oscillator is supplied by an external 32.768 kHz
crystal. The Watchdog Timer source clock is then subdivided by a ratio of 28 to 218 to give longer
timeouts, the actual value being chosen using the WS2~WS0 bits in the WDTC register.
Watchdog Timer Control Register
A single register, WDTC, controls the required timeout period as well as the enable or reset
operation.
Rev. 1.00
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A/D 8-Bit Flash MCU with EEPROM
WDTC Register
Bit
7
6
5
4
3
2
1
0
Name
WE4
WE3
WE2
WE1
WE0
WS2
WS1
WS0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
1
0
1
0
0
1
1
Bit 7~ 3
WE4 ~ WE0: WDT function software control
10101/01010: WDT enable
Other values: Reset MCU
When these bits are changed to any other values by the environmental noise to reset
the microcontroller, the reset operation will be activated after 2~3 tSUB clock cycles
and the WRF bit in the CTRL register will be set to 1to indicate the reset source.
Bit 2~ 0
WS2 ~ WS0: WDT Time-out period selection
000: 28/fSUB
001: 210/fSUB
010: 212/fSUB
011: 214/fSUB
100: 215/fSUB
101: 216/fSUB
110: 217/fSUB
111: 218/fSUB
These three bits determine the division ratio of the Watchdog Timer sourece clock,
which in turn determines the timeout period.
CTRL Register
Bit
7
6
5
4
3
2
Name
FSYSON
—
—
—
—
R/W
R/W
—
—
—
—
POR
0
—
—
—
—
Bit 7
FSYSON: fSYS Control IDLE Mode
Describe elsewhere
Bit 6~ 3
Unimplemented, read as “0”
1
0
LVRF
LRF
WRF
R/W
R/W
R/W
0
0
0
Bit 2LVRF: LVR function reset flag
Describe elsewhere
Bit 1LRF: LVRC register software reset flag
Describe elsewhere
Bit 0WRF: WDTC register software reset flag
0: Not occur
1: Occurred
This bit is set to 1 by the WDTC Control register software reset and cleared by the
application program. Note that this bit can only be cleared to 0 by the application
program.
Rev. 1.00
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A/D 8-Bit Flash MCU with EEPROM
Watchdog Timer Operation
The Watchdog Timer operates by providing a device reset when its timer overflows. This means
that in the application program and during normal operation the user has to strategically clear the
Watchdog Timer before it overflows to prevent the Watchdog Timer from executing a reset. This is
done using the clear watchdog instructions. If the program malfunctions for whatever reason, jumps
to an unknown location, or enters an endless loop, the clear WDT instructions will not be executed
in the correct manner, in which case the Watchdog Timer will overflow and reset the device. With
regard to the Watchdog Timer enable/reset function, there are five bits, WE4~WE0, in the WDTC
register to additional enable and reset control of the Watchdog Timer.
WE4 ~ WE0 Bits
WDT Function
10101B/01010B
Enable
Any other value
Reset MCU
Watchdog Timer Enable/Reset Control
Under normal program operation, a Watchdog Timer time-out will initialise a device reset and set
the status bit TO. However, if the system is in the SLEEP or IDLE Mode, when a Watchdog Timer
time-out occurs, the TO bit in the status register will be set and only the Program Counter and Stack
Pointer will be reset. Three methods can be adopted to clear the contents of the Watchdog Timer.
The first is a WDT reset, which means a value other than 01010B and 10101B is written into the
WE4~WE0 bit locations, the second is using the Watchdog Timer software clear instructions and the
third is via a HALT instruction. There is only one method of using software instruction to clear the
Watchdog Timer. That is to use the single “CLR WDT” instruction to clear the WDT.
The maximum time-out period is when the 218 division ratio is selected. As an example, with a 32
kHz LIRC oscillator as its source clock, this will give a maximum watchdog period of around 8
seconds for the 218 division ratio, and a minimum timeout of 7.8ms for the 28 division ration.
WDTC Register WE4~WE0 bits
Reset MCU
CLR
“CLR WDT”Instruction
LXT
LIRC
M
U
X
fSUB
Configuration option
8-stage Divider
fSUB/28
WS2~WS0
(fSUB/28 ~ fSUB/218)
WDT Prescaler
8-to-1 MUX
WDT Time-out
(28/fSUB ~ 218/fSUB)
Watchdog Timer
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A/D 8-Bit Flash MCU with EEPROM
Reset and Initialisation
A reset function is a fundamental part of any microcontroller ensuring that the device can be set
to some predetermined condition irrespective of outside parameters. The most important reset
condition is after power is first applied to the microcontroller. In this case, internal circuitry will
ensure that the microcontroller, after a short delay, will be in a well defined state and ready to
execute the first program instruction. After this power-on reset, certain important internal registers
will be set to defined states before the program commences. One of these registers is the Program
Counter, which will be reset to zero forcing the microcontroller to begin program execution from the
lowest Program Memory address.
Another type of reset is when the Watchdog Timer overflows and resets the microcontroller. All
types of reset operations result in different register conditions being setup. Another reset exists in the
form of a Low Voltage Reset, LVR, where a full reset is implemented in situations where the power
supply voltage falls below a certain threshold.
Reset Functions
There are several ways in which a microcontroller reset can occur, through events occurring both
internally and externally:
Power-on Reset
The most fundamental and unavoidable reset is the one that occurs after power is first applied to
the microcontroller. As well as ensuring that the Program Memory begins execution from the first
memory address, a power-on reset also ensures that certain other registers are preset to known
conditions. All the I/O port and port control registers will power up in a high condition ensuring that
all pins will be first set to inputs.
Note: tRSTD is power-on delay, typical time=50ms
Power-On Reset Timing Chart
Low Voltage Reset – LVR
The microcontroller contains a low voltage reset circuit in order to monitor the supply voltage of
the device, which is always enabled selected by the configuration option. If the supply voltage of
the device drops to within a range of 0.9V~VLVR such as might occur when changing the battery, the
LVR will automatically reset the device internally and the LVRF bit in the CTRL register will also
be set to1. For a valid LVR signal, a low voltage, i.e., a voltage in the range between 0.9V~ VLVR
must exist for greater than the value tLVR specified in the A.C. characteristics. If the low voltage
state does not exceed this value, the LVR will ignore the low supply voltage and will not perform a
reset function. The actual VLVR can be selected by the LVS7~LVS0 bits in the LVRC register. If the
LVS7~LVS0 bits are changed to some certain values by the environmental noise, the LVR will reset
the device after 2~3 LIRC/LXT clock cycles. When this happens, the LRF bit in the CTRL register
will be set to 1. After power on the register will have the value of 01010101B. Note that the LVR
function will be automatically disabled when the device enters the power down mode.
Note:tRSTD is power-on delay, typical time=50ms
Low Voltage Reset Timing Chart
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A/D 8-Bit Flash MCU with EEPROM
• LVRC Register
Bit
7
6
5
4
3
2
1
0
Name
LVS7
LVS6
LVS5
LVS4
LVS3
LVS2
LVS1
LVS0
R/W
R/W
R/W
R/W
R/W
R
R
R/W
R/W
POR
0
1
0
1
0
1
0
1
Bit 7 ~ 0
LVS7 ~ LVS0: LVR Voltage Select control
01010101: 2.1V
00110011: 2.55V
10011001: 3.15V
10101010: 3.8V
Other values: MCU reset – register is reset to POR value
When an actual low voltage condition occurs, as specified by one of the four defined
LVR voltage values above, an MCU reset will be generated. The reset operation will
be activated after 2~3 LIRC/LXT clock cycles. In this situation this register contents
will remain the same after such a reset occurs.
• CTRL Register
Bit
7
6
5
4
3
2
1
0
Name
FSYSON
—
—
—
—
LVRF
LRF
WRF
R/W
R/W
—
—
—
—
R/W
R/W
R/W
POR
0
—
—
—
—
0
0
0
Bit 7
FSYSON: fSYS Control IDLE Mode
Describe elsewhere
Bit 6~ 3
Unimplemented, read as “0”
Bit 2LVRF: LVR function reset flag
0: Not occur
1: Occurred
This bit is set to 1 when a specific Low Voltage Reset situation condition occurs. This
bit can only be cleared to zero by the application program.
Bit 1LRF: LVRC register software reset flag
0: Not occur
1: Occurred
This bit is set to 1 if the LVRC register contains any non defined LVR voltage register
values. This in effect acts like a software reset function. This bit can only be cleared to
zero by the application program.
Bit 0WRF: WDTC register software reset flag
Describe elsewhere
Watchdog Time-out Reset during Normal Operation
The Watchdog time-out Reset during normal operation is the same as an LVR reset except that the
Watchdog time-out flag TO will be set to “1”.
Note: tRSTD is power-on delay, typical time=16.7ms
WDT Time-out Reset during Normal Operation Timing Chart
Rev. 1.00
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HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Watchdog Time-out Reset during SLEEP or IDLE Mode
The Watchdog time-out Reset during SLEEP or IDLE Mode is a little different from other kinds
of reset. Most of the conditions remain unchanged except that the Program Counter and the Stack
Pointer will be cleared to “0” and the TO flag will be set to “1”. Refer to the A.C. Characteristics for
tSST details.
Note: The tSST is 15~16 clock cycles if the system clock source is provided by the HIRC. The tSST is 128 clock cycles for HXT/LXT. The tSST is 1~2 clock cycles for the LIRC.
WDT Time-out Reset during SLEEP or IDLE Timing Chart
Reset Initial Conditions
The different types of reset described affect the reset flags in different ways. These flags, known
as PDF and TO are located in the status register and are controlled by various microcontroller
operations, such as the SLEEP or IDLE Mode function or Watchdog Timer. The reset flags are
shown in the table:
TO
PDF
RESET Conditions
0
0
Power-on reset
u
u
LVR reset during NORMAL or SLOW Mode operation
1
u
WDT time-out reset during NORMAL or SLOW Mode operation
1
1
WDT time-out reset during IDLE or SLEEP Mode operation
Note: “u” stands for unchanged
The following table indicates the way in which the various components of the microcontroller are
affected after a power-on reset occurs.
Item
Condition After RESET
Program Counter
Reset to zero
Interrupts
All interrupts will be disabled
WDT
Clear after reset, WDT begins counting
Timer Modules
Timer Modules will be turned off
Input/Output Ports
I/O ports will be setup as inputs
Stack Pointer
Stack Pointer will point to the top of the stack
The different kinds of resets all affect the internal registers of the microcontroller in different ways.
To ensure reliable continuation of normal program execution after a reset occurs, it is important to
know what condition the microcontroller is in after a particular reset occurs. The following table
describes how each type of reset affects each of the microcontroller internal registers. Note that
where more than one package type exists the table will reflect the situation for the larger package
type.
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A/D 8-Bit Flash MCU with EEPROM
Register
Reset
(Power On)
WDT Time-out
(Normal Operation)
LVR Reset
WDT Time-out
(HALT)
IAR0
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
MP0
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
IAR1
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
MP1L
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
MP1H
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
IAR2
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
MP2L
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
MP2H
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
ACC
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
PCL
0000 0000
0000 0000
0000 0000
0000 0000
TBLP
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
TBLH
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
TBHP
---x xxxx
---u uuuu
---u uuuu
---u uuuu
STATUS
xx00 xxxx
uu1u uuuu
uuuu uuuu
u u 11 u u u u
SMOD
0 0 0 0 0 0 11
0 0 0 0 0 0 11
0 0 0 0 0 0 11
uuuu uuuu
INTEG0
0000 0000
0000 0000
0000 0000
uuuu uuuu
INTEG1
---- 0000
---- 0000
---- 0000
---- uuuu
WDTC
0 1 0 1 0 0 11
0 1 0 1 0 0 11
0 1 0 1 0 0 11
uuuu uuuu
TBC
0 0 11 0 111
0 0 11 0 111
0 0 11 0 111
uuuu uuuu
INTC0
-000 0000
-000 0000
-000 0000
-uuu uuuu
INTC1
0000 0000
0000 0000
0000 0000
uuuu uuuu
INTC2
0000 0000
0000 0000
0000 0000
uuuu uuuu
INTC3
0000 0000
0000 0000
0000 0000
uuuu uuuu
MFI0
--00 --00
--00 --00
--00 --00
--uu --uu
MFI1
0-00 --00
0-00 --00
0-00 --00
u-uu --uu
MFI2
0000 0000
0000 0000
0000 0000
uuuu uuuu
PAWU
0000 0000
0000 0000
0000 0000
uuuu uuuu
PAPU
0000 0000
0000 0000
0000 0000
uuuu uuuu
PA
1111 1111
1111 1111
1111 1111
uuuu uuuu
PAC
1111 1111
1111 1111
1111 1111
uuuu uuuu
PBPU
0000 0000
0000 0000
0000 0000
uuuu uuu0
PB
1111 1111
1111 1111
1111 1111
uuuu uuuu
PBC
1111 1111
1111 1111
1111 1111
uuuu uuuu
PCPU
0000 0000
0000 000
0000 0000
uuuu uuuu
PC
1111 1111
1111 1111
1111 1111
uuuu uuuu
PCC
1111 1111
1111 1111
1111 1111
uuuu uuuu
PDPU
--00 0000
--00 0000
--00 0000
--uu uuuu
PD
- - 11 1111
- - 11 1111
- - 11 1111
--uu uuuu
PDC
- - 11 1111
- - 11 1111
- - 11 1111
--uu uuuu
IOHR0
0000 0000
0000 0000
0000 0000
uuuu uuuu
IOHR1
0000 0000
0000 0000
0000 0000
uuuu uuuu
IOHR2
0000 0000
0000 0000
0000 0000
uuuu uuuu
IOHR3
0000 0000
0000 0000
0000 0000
uuuu uuuu
CTRL
0--- -000
0--- -000
0--- -000
u--- -uuu
LVRC
0101 0101
0101 0101
uuuu uuuu
uuuu uuuu
ADRL(ADRFS=0)
xxxx ----
xxxx ----
xxxx ----
uuuu ----
ADRL(ADRFS=1)
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
ADRH(ADRFS=0)
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
Rev. 1.00
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HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Register
Reset
(Power On)
WDT Time-out
(Normal Operation)
LVR Reset
WDT Time-out
(HALT)
ADRH(ADRFS=1)
---- xxxx
---- xxxx
---- xxxx
---- uuuu
ADCR0
0 11 0 - 0 0 0
0 11 0 - 0 0 0
0 11 0 - 0 0 0
uuuu -uuu
ADCR1
00--0000
00-- 0000
00-- 0000
uu-- uuuu
ACERL
1111 1111
1111 1111
1111 1111
uuuu uuuu
TMPC0
-0-0 -0-0
-0-0 -0-0
-0-0 -0-0
-u-u -u-u
EEA
--00 0000
--00 0000
--00 0000
--uu uuuu
EED
0000 0000
0000 0000
0000 0000
uuuu uuuu
EEC
---- 0000
---- 0000
---- 0000
---- uuuu
CTMC0
0000 0000
0000 0000
0000 0000
uuuu uuuu
CTMC1
0000 0000
0000 0000
0000 0000
uuuu uuuu
CTMDL
0000 0000
0000 0000
0000 0000
uuuu uuuu
CTMDH
---- --00
---- --00
---- --00
---- --uu
CTMAL
0000 0000
0000 0000
0000 0000
uuuu uuuu
CTMAH
---- --00
---- --00
---- --00
---- --uu
STMC0
0000 0---
0000 0---
0000 0---
uuuu u---
STMC1
0000 0000
0000 0000
0000 0000
uuuu uuuu
STMDL
0000 0000
0000 0000
0000 0000
uuuu uuuu
STMDH
0000 0000
0000 0000
0000 0000
uuuu uuuu
STMAL
0000 0000
0000 0000
0000 0000
uuuu uuuu
STMAH
0000 0000
0000 0000
0000 0000
uuuu uuuu
STMRP
0000 0000
0000 0000
0000 0000
uuuu uuuu
PTM0C0
0000 0---
0000 0---
0000 0---
uuuu u---
PTM0C1
0000 0000
0000 0000
0000 0000
uuuu uuuu
PTM0DL
0000 0000
0000 0000
0000 0000
uuuu uuuu
PTM0DH
---- --00
---- --00
---- --00
---- --uu
PTM0AL
0000 0000
0000 0000
0000 0000
uuuu uuuu
PTM0AH
---- --00
---- --00
---- --00
---- --uu
PTM0RPL
0000 0000
0000 0000
0000 0000
uuuu uuuu
PTM0RPH
---- --00
---- --00
---- --00
---- --uu
PTM1C0
0000 0---
0000 0---
0000 0---
uuuu u---
PTM1C1
0000 0000
0000 0000
0000 0000
uuuu uuuu
PTM1DL
0000 0000
0000 0000
0000 0000
uuuu uuuu
PTM1DH
---- --00
---- --00
---- --00
---- --uu
PTM1AL
0000 0000
0000 0000
0000 0000
uuuu uuuu
PTM1AH
---- --00
---- --00
---- --00
---- --uu
PTM1RPL
0000 0000
0000 0000
0000 0000
uuuu uuuu
PTM1RPH
---- --00
---- --00
---- --00
---- --uu
SIMTOC
0000 0000
0000 0000
0000 0000
uuuu uuuu
SIMC0
111 - 0 0 0 0
111 - 0 0 0 0
111 - 0 0 0 0
uuu- uuuu
SIMC1
1000 0001
1000 0001
1000 0001
uuuu uuuu
SIMD
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
SIMA
0000 000-
0000 000-
0000 000-
uuuu uuuu
SIMC2
0000 0000
0000 0000
0000 0000
uuuu uuuu
LVDC
--00 -000
--00 -000
--00 -000
--uu -uuu
USR
0 0 0 0 1 0 11
0 0 0 0 1 0 11
0 0 0 0 1 0 11
uuuu uuuu
UCR1
0000 00x0
0000 00x0
0000 00x0
uuuu uuuu
UCR2
0000 0000
0000 0000
0000 0000
uuuu uuuu
BRG
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
Rev. 1.00
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HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Reset
(Power On)
WDT Time-out
(Normal Operation)
LVR Reset
WDT Time-out
(HALT)
TXR/RXR
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
SLCDC0
0000 0000
0000 0000
0000 0000
uuuu uuuu
SLCDC1
0000 0000
0000 0000
0000 0000
uuuu uuuu
SLCDC2
0000 0000
0000 0000
0000 0000
uuuu uuuu
SLCDC3
0000 0000
0000 0000
0000 0000
uuuu uuuu
SLCDC4
0000 0000
0000 0000
0000 0000
uuuu uuuu
Register
Note: "-" not implement
"u" stands for "unchanged"
"x" stands for "unknown"
Input/Output Ports
Holtek microcontrollers offer considerable flexibility on their I/O ports. With the input or output
designation of every pin fully under user program control, pull-high selections for all ports and
wake-up selections on certain pins, the user is provided with an I/O structure to meet the needs of a
wide range of application possibilities.
The device provides bidirectional input/output lines labeled with port names PA~PD. These I/O
ports are mapped to the RAM Data Memory with specific addresses as shown in the Special Purpose
Data Memory table. All of these I/O ports can be used for input and output operations. For input
operation, these ports are non-latching, which means the inputs must be ready at the T2 rising edge
of instruction “MOV A, [m]”, where m denotes the port address. For output operation, all the data is
latched and remains unchanged until the output latch is rewritten.
Bit
Register
Name
7
6
5
4
3
2
1
0
PAWU
PAWU7
PAWU6
PAWU5
PAWU4
PAWU3
PAWU2
PAWU1
PAWU0
PAPU
PAPU7
PAPU6
PAPU5
PAPU4
PAPU3
PAPU2
PAPU1
PAPU0
PA
PA7
PA6
PA5
PA4
PA3
PA2
PA1
PA0
PAC
PAC7
PAC6
PAC5
PAC4
PAC3
PAC2
PAC1
PAC0
PBPU
PBPU7
PBPU6
PBPU5
PBPU4
PBPU3
PBPU2
PBPU1
PBPU0
PB
PB7
PB 6
PB 5
PB4
PB3
PB2
PB1
PB0
PBC
PBC7
PBC6
PBC5
PBC4
PBC3
PBC2
PBC1
PBC0
PCPU
PCPU7
PCPU6
PCPU5
PCPU4
PCPU3
PCPU2
PCPU1
PCPU0
PC
PC7
PC6
PC5
PC4
PC3
PC2
PC1
PC0
PCC
PCC7
PCC6
PCC5
PCC4
PCC3
PCC2
PCC1
PCC0
PDPU0
PDPU
—
—
PDPU5
PDPU4
PDPU3
PDPU2
PDPU1
PD
—
—
PD5
PD4
PD3
PD2
PD1
PD0
PDC
—
—
PDC5
PDC4
PDC3
PDC2
PDC1
PDC0
I/O Control Register List
PAPUn, PBPUn, PCPUn, PDPUn: I/O Port Pull-High Control
0: Disable
1: Enable
PAWUn: I/O Port A bit 7 ~ bit 0 Wake Up Control
0: Disable
1: Enable
PACn, PBCn, PCCn, PDCn: I/O Port Input/Output Control
0: Output
1: Input
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Pull-high Resistors
Many product applications require pull-high resistors for their switch inputs usually requiring the
use of an external resistor. To eliminate the need for these external resistors, all I/O pins, when
configured as an input have the capability of being connected to an internal pull-high resistor. These
pull-high resistors are selected using registers PAPU~PDPU, and are implemented using weak
PMOS transistors.
Port A Wake-up
The HALT instruction forces the microcontroller into the SLEEP or IDLE Mode which preserves
power, a feature that is important for battery and other low-power applications. Various methods
exist to wake-up the microcontroller, one of which is to change the logic condition on one of the Port
A pins from high to low. This function is especially suitable for applications that can be woken up
via external switches. Each pin on Port A can be selected individually to have this wake-up feature
using the PAWU register.
I/O Port Control Registers
Each I/O port has its own control register known as PAC~PDC, to control the input/output
configuration. With this control register, each CMOS output or input can be reconfigured
dynamically under software control. Each pin of the I/O ports is directly mapped to a bit in its
associated port control register. For the I/O pin to function as an input, the corresponding bit of the
control register must be written as a “1”. This will then allow the logic state of the input pin to be
directly read by instructions. When the corresponding bit of the control register is written as a “0”,
the I/O pin will be setup as a CMOS output. If the pin is currently setup as an output, instructions
can still be used to read the output register. However, it should be noted that the program will in fact
only read the status of the output data latch and not the actual logic status of the output pin.
Pin-shared Functions
The flexibility of the microcontroller range is greatly enhanced by the use of pins that have more
than one function. Limited numbers of pins can force serious design constraints on designers but by
supplying pins with multi-functions, many of these difficulties can be overcome. For some pins, the
chosen function of the multi-function I/O pins is set by configuration options while for others the
function is set by application program control.
I/O Pin Structures
The accompanying diagrams illustrate the internal structures of some generic I/O pin types. As
the exact logical construction of the I/O pin will differ from these drawings, they are supplied as a
guide only to assist with the functional understanding of the I/O pins. The wide range of pin-shared
structures does not permit all types to be shown.
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A/D 8-Bit Flash MCU with EEPROM
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I/O Port source current selection
The PA~PD input/output ports have programmable source current functions. Four levels of source
current can be selected by the registers.
IOHR0 Register
Bit
7
6
5
4
3
2
1
0
Name
IOHS31
IOHS30
IOHS21
IOHS20
IOHS11
IOHS10
IOHS01
IOHS00
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7~6IOHS31~IOHS30: PA3 source current output selection bit
00: Full source current output
01: 10/22 full source current output
10: 7/22 full source current output
11: 4/22 full source current output
Bit 5~4IOHS21~IOHS20: PA2 source current output selection bit
00: Full source current output
01: 10/22 full source current output
10: 7/22 full source current output
11: 4/22 full source current output
Bit 3~2IOHS11~IOHS10: PA1 source current output selection bit
00: Full source current output
01: 10/22 full source current output
10: 7/22 full source current output
11: 4/22 full source current output
Bit 1~0IOHS01~IOHS00: PA0 source current output selection bit
00: Full source current output
01: 10/22 full source current output
10: 7/22 full source current output
11: 4/22 full source current output
IOHR1 Register
Bit
7
6
5
4
3
2
1
0
Name
IOHS71
IOHS70
IOHS61
IOHS60
IOHS51
IOHS50
IOHS41
IOHS40
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7~6IOHS71~IOHS70: PA7 source current output selection bit
00: Full source current output
01: 10/22 full source current output
10: 7/22 full source current output
11: 4/22 full source current output
Bit 5~4IOHS61~IOHS60: PA6 source current output selection bit
00: Full source current output
01: 10/22 full source current output
10: 7/22 full source current output
11: 4/22 full source current output
Bit 3~2IOHS51~IOHS50: PA5 source current output selection bit
00: Full source current output
01: 10/22 full source current output
10: 7/22 full source current output
11: 4/22 full source current output
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Bit 1~0IOHS41~IOHS40: PA4 source current output selection bit
00: Full source current output
01: 10/22 full source current output
10: 7/22 full source current output
11: 4/22 full source current output
IOHR2 Register
Bit
7
6
5
4
3
2
1
0
Name
IOHSB1
IOHSB0
IOHSA1
IOHSA0
IOHS91
IOHS90
IOHS81
IOHS80
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7~6IOHSB1~IOHSB0: PC4~PC7 source current output selection bit
00: Full source current output
01: 10/22 full source current output
10: 7/22 full source current output
11: 4/22 full source current output
Bit 5~4IOHSA1~IOHSA0: PC0~PC3 source current output selection bit
00: Full source current output
01: 10/22 full source current output
10: 7/22 full source current output
11: 4/22 full source current output
Bit 3~2IOHS91~IOHS90: PB4~PB7 source current output selection bit
00: Full source current output
01: 10/22 full source current output
10: 7/22 full source current output
11: 4/22 full source current output
Bit 1~0IOHS81~IOHS80: PB0~PB3 source current output selection bit
00: Full source current output
01: 10/22 full source current output
10: 7/22 full source current output
11: 4/22 full source current output
IOHR3 Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
IOHSD1
IOHSD0
IOHSC1
IOHSC0
R/W
—
—
—
—
R/W
R/W
R/W
R/W
POR
—
—
—
—
0
0
0
0
Bit 7~4
Unimplemented, read as “0”
Bit 3~2IOHSD1~IOHSD0: PD4~PD5 source current output selection bit
00: Full source current output
01: 10/22 full source current output
10: 7/22 full source current output
11: 4/22 full source current output
Bit 1~0IOHSC1~IOHSC0: PD0~PD3 source current output selection bit
00: Full source current output
01: 10/22 full source current output
10: 7/22 full source current output
11: 4/22 full source current output
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Programming Considerations
Within the user program, one of the first things to consider is port initialisation. After a reset, all of
the I/O data and port control registers will be set high. This means that all I/O pins will default to
an input state, the level of which depends on the other connected circuitry and whether pull-high
selections have been chosen. If the port control registers, PAC~PDC, are then programmed to setup
some pins as outputs, these output pins will have an initial high output value unless the associated
port data registers, PA~PD, are first programmed. Selecting which pins are inputs and which are
outputs can be achieved byte-wide by loading the correct values into the appropriate port control
register or by programming individual bits in the port control register using the “SET [m].i” and
“CLR [m].i” instructions. Note that when using these bit control instructions, a read-modify-write
operation takes place. The microcontroller must first read in the data on the entire port, modify it to
the required new bit values and then rewrite this data back to the output ports.
Port A has the additional capability of providing wake-up functions. When the device is in the
SLEEP or IDLE Mode, various methods are available to wake the device up. One of these is a high
to low transition of any of the Port A pins. Single or multiple pins on Port A can be setup to have this
function.
Timer Modules – TM
One of the most fundamental functions in any microcontroller device is the ability to control and
measure time. To implement time related functions the device includes several Timer Modules,
abbreviated to the name TM. The TMs are multi-purpose timing units and serve to provide
operations such as Timer/Counter, Input Capture, Compare Match Output and Single Pulse Output
as well as being the functional unit for the generation of PWM signals. Each of the TMs has two
individual interrupts. The addition of input and output pins for each TM ensures that users are
provided with timing units with a wide and flexible range of features.
The common features of the different TM types are described here with more detailed information
provided in the individual Compact, Standard and Periodic TM sections.
Introduction
The device contains a 10-bit Compact TM-CTM, a 16-bit Standard TM-STM and two10-bit Periodic
TMs- PTM0 and PTM1. Although similar in nature, the different TM types vary in their feature
complexity. The common features to the Compact, Standard and Periodic TMs will be described in
this section and the detailed operation will be described in corresponding sections. The main features
and differences between the three types of TMs are summarised in the accompanying table.
CTM
STM
Timer/Counter
Function
√
√
PTM
√
I/P Capture
—
√
√
Compare Match Output
√
√
√
PWM Channels
1
1
1
Single Pulse Output
PWM Alignment
PWM Adjustment Period & Duty
—
1
1
Edge
Edge
Edge
Duty or Period
Duty or Period
Duty or Period
TM Function Summary
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TM Operation
The three different types of TMs offer a diverse range of functions, from simple timing operations
to PWM signal generation. The key to understanding how the TM operates is to see it in terms of
a free running counter whose value is then compared with the value of pre-programmed internal
comparators. When the free running counter has the same value as the pre-programmed comparator,
known as a compare match situation, a TM interrupt signal will be generated which can clear the
counter and perhaps also change the condition of the TM output pin. The internal TM counter is
driven by a user selectable clock source, which can be an internal clock or an external pin.
TM Clock Source
The clock source which drives the main counter in each TM can originate from various sources. The
selection of the required clock source is implemented using the xTnCK2~xTnCK0 bits in the TM
control registers. The clock source can be a ratio of either the system clock fSYS or the internal high
clock fH, the fTBC clock source or the external xTCKn pin. The xTCKn pin clock source is used to
allow an external signal to drive the TM as an external clock source or for event counting.
TM Interrupts
The Compact, Standard and Periodic type TMs each has two internal interrupts, the internal
comparator A or comparator P, which generate a TM interrupt when a compare match condition
occurs. When a TM interrupt is generated, it can be used to clear the counter and also to change the
state of the TM output pin. TM External Pins
Each of the TMs, irrespective of what type, has one TM input pin, with the label xTCKn. The TM
input pin, is essentially a clock source for the TM and is selected using the xTnCK2~xTnCK0 bits
in the xTMnC0 register. This external TM input pin allows an external clock source to drive the
internal TM. This external TM input pin is shared with other functions but will be connected to the
internal TM if selected using the xTnCK2~xTnCK0 bits. The TM input pin can be chosen to have
either a rising or falling active edge.
The TMs each have one output pin. When the TM is in the Compare Match Output Mode, these pins
can be controlled by the TM to switch to a high or low level or to toggle when a compare match
situation occurs. The external xTPn output pin is also the pin where the TM generates the PWM
output waveform. As the TM output pins are pin-shared with other function, the TM output function
must first be setup using registers. A single bit in one of the registers determines if its associated pin
is to be used as an external TM output pin or if it is to have another function. The number of output
pins for each TM type is different, the details are provided in the accompanying table.
TM Type
Pin
Input
Output
CTP
CTM
CTM
CTCK
STM
STM
STCK
STP
PTM0
PTCK0
PTP0
PTM1
PTCK1
PTP1
PTM
TM Input/Output pin
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A/D 8-Bit Flash MCU with EEPROM
TM Input/Output Pin Control Register
Selecting to have a TM input/output or whether to retain its other shared function is implemented
using one register, with a single bit in the register corresponding to a TM input/output pin. Setting
the bit high will setup the corresponding pin as a TM input/output, if reset to zero the pin will retain
its original other function.
TMPC0 Register
Bit
7
6
5
4
3
2
1
0
Name
—
PTP1CP0
—
PTP0CP0
—
STPCP0
—
CTPCP0
R/W
—
R/W
—
R/W
—
R/W
—
R/W
POR
—
0
—
0
—
0
—
0
Bit 7
Unimplemented, read as
Bit 6PTP1CP0: PTP1 pin Control
0: Normal I/O
1: PTP1 function
Bit 5
Unimplemented, read as
Bit 4PTP0CP0: PTP0 pin Control
0: Normal I/O
1: PTP0 function
Bit 3
Unimplemented, read as
Bit 2STPCP0: STP pin Control
0: Normal I/O
1: STP function
Bit 1
Unimplemented, read as
Bit 0CTPCP0: CTP pin Control
0: Normal I/O
1: CTP function
PB2 data bit
CTM Mode Controller
(CTM)
1
CTP
CTP
0
CTPCP0
CTM Function Pin Control Block Diagram
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PB7 data bit
1
STP
0
STPCP0
STPCP0
1
0
STM Mode Controller
(STM)
0
STP
STP
STM Function Pin Control Block Diagram
PB0 data bit
1
PTP0
0
PTP0CP0
PTP0CP0
1
0
PTM Mode Controller
(PTM0)
0
PTP0
PTP0
PA5 data bit
1
PTP1
0
PTP1CP0
PTP1CP0
1
0
PTM Mode Controller
(PTM1)
0
PTP1
PTP1
PTM0, PTM1 Function Pin Control Block Diagram
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Programming Considerations
The TM Counter Registers and the Capture/Compare CCRA or CCRP register, being either 10-bit or
16-bit, all have a low and high byte structure. The high bytes can be directly accessed, but as the low
bytes can only be accessed via an internal 8-bit buffer, reading or writing to these register pairs must
be carried out in a specific way. The important point to note is that data transfer to and from the 8-bit
buffer and its related low byte only takes place when a write or read operation to its corresponding
high byte is executed.
As the CCRA and CCRP registers are implemented in the way shown in the following diagram and
accessing this register is carried out in a specific way described above, it is recommended to use the
“MOV” instruction to access the CCRA or CCRP low byte register, named xTMnAL or PTMnRPL,
in the following access procedures. Accessing the CCRA or CCRP low byte register without
following these access procedures will result in unpredictable values.
TM Counter Register (Read only)
xTMnDL xTMnDH
8-bit
Buffer
xTMnAL xTMnAH
xTM CCRA Register (Read/Write)
PTMnRPL PTMnRPH
PTMn CCRP Register (Read/Write)
Data Bus
The following steps show the read and write procedures:
• Writing Data to CCRA or CCRP
♦♦
Step 1. Write data to Low Byte xTMnAL or PTMnRPL
––Note that here data is only written to the 8-bit buffer.
♦♦
Step 2. Write data to High Byte xTMnAH or PTMnRPH
––Here data is written directly to the high byte registers and simultaneously data is latched
from the 8-bit buffer to the Low Byte registers.
• Reading Data from the Counter Registers and CCRA or CCRP
Rev. 1.00
♦♦
Step 1. Read data from the High Byte xTMnDH, xTMnAH or PTMnRPH
––Here data is read directly from the High Byte registers and simultaneously data is latched
from the Low Byte register into the 8-bit buffer.
♦♦
Step 2. Read data from the Low Byte xTMnDL, xTMnAL or PTMnRPL
––This step reads data from the 8-bit buffer.
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Compact Type TM – CTM
Although the simplest form of the three TM types, the Compact TM type still contains three
operating modes, which are Compare Match Output, Timer/Event Counter and PWM Output modes.
The Compact TM can also be controlled with an external input pin and can drive one external output
pin.
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Compact TM Operation
At its core is a 10-bit count-up counter which is driven by a user selectable internal or external clock
source. There are also two internal comparators with the names, Comparator A and Comparator
P. These comparators will compare the value in the counter with CCRP and CCRA registers. The
CCRP is three bits wide whose value is compared with the highest three bits in the counter while the
CCRA is the ten bits and therefore compares with all counter bits.
The only way of changing the value of the 10-bit counter using the application program, is to
clear the counter by changing the CTON bit from low to high. The counter will also be cleared
automatically by a counter overflow or a compare match with one of its associated comparators.
When these conditions occur, a TM interrupt signal will also usually be generated. The Compact
Type TM can operate in a number of different operational modes, can be driven by different clock
sources including an input pin and can also control two output pins. All operating setup conditions
are selected using relevant internal registers.
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Compact Type TM Register Description
Overall operation of each Compact TM is controlled using several registers. A read only register
pair exists to store the internal counter 10-bit value, while a read/write register pair exists to store
the internal 10-bit CCRA value. The remaining two registers are control registers which setup the
different operating and control modes as well as the three CCRP bits.
Bit
Register
Name
7
6
5
4
3
2
1
0
CTMC0
CTPAU
CTCK2
CTCK1
CTCK0
CTON
CTRP2
CTRP1
CTRP0
CTMC1
CTM1
CTM0
CTIO1
CTIO0
CTOC
CTPOL
CTDPX
CTCCLR
CTMDL
D7
D6
D5
D4
D3
D2
D1
D0
CTMDH
—
—
—
—
—
—
D9
D8
CTMAL
D7
D6
D5
D4
D3
D2
D1
D0
CTMAH
—
—
—
—
—
—
D9
D8
Compact TM Register List
CTMC0 Register
Bit
7
6
5
4
3
2
1
0
Name
CTPAU
CTCK2
CTCK1
CTCK0
CTON
CTRP2
CTRP1
CTRP0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7CTPAU: CTM Counter Pause Control
0: Run
1: Pause
The counter can be paused by setting this bit high. Clearing the bit to zero restores
normal counter operation. When in a Pause condition the TM will remain powered up
and continue to consume power. The counter will retain its residual value when this bit
changes from low to high and resume counting from this value when the bit changes
to a low value again.
Bit 6 ~ 4
CTCK2 ~ CTCK0: Select CTM Counter clock
000: fSYS/4
001: fSYS
010: fH/16
011: fH/64
100: fTBC
101: fTBC
110: CTCK rising edge clock
111: CTCK falling edge clock
These three bits are used to select the clock source for the CTM. The external pin
clock source can be chosen to be active on the rising or falling edge. The clock source
fSYS is the system clock, while fH and fTBC are other internal clocks, the details of which
can be found in the oscillator section.
Bit 3CTON: CTM Counter On/Off Control
0: Off
1: On
This bit controls the overall on/off function of the TM. Setting the bit high enables the
counter to run, clearing the bit disables the TM. Clearing this bit to zero will stop the
counter from counting and turn off the TM which will reduce its power consumption.
When the bit changes state from low to high the internal counter value will be reset to
zero, however when the bit changes from high to low, the internal counter will retain
its residual value until the bit returns high again.
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If the TM is in the Compare Match Output Mode then the TM output pin will be reset
to its initial condition, as specified by the CTOC bit, when the CTON bit changes from
low to high.
Bit 2 ~ 0CTRP2~CTRP0: CTM CCRP 3-bit register, compared with the CTM Counter bit9~bit7
Comparator P Match Period
000: 1024 CTM clocks
001: 128 CTM clocks
010: 256 CTM clocks
011: 384 CTM clocks
100: 512 CTM clocks
101: 640 CTM clocks
110: 768 CTM clocks
111: 896 CTM clocks
These three bits are used to setup the value on the internal CCRP 3-bit register, which
are then compared with the internal counter's highest three bits. The result of this
comparison can be selected to clear the internal counter if the CTCCLR bit is set to
zero. Setting the CTCCLR bit to zero ensures that a compare match with the CCRP
values will reset the internal counter. As the CCRP bits are only compared with the
highest three counter bits, the compare values exist in 128 clock cycle multiples.
Clearing all three bits to zero is in effect allowing the counter to overflow at its
maximum value.
CTMC1 Register
Bit
7
6
5
4
3
2
1
0
Name
CTM1
CTM0
CTIO1
CTIO0
CTOC
CTPOL
CTDPX
CTCCLR
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7 ~ 6CTM1~CTM0: Select CTM Operating Mode
00: Compare Match Output Mode
01: Compare Match Output Mode
10: PWM Mode
11: Timer/Counter Mode
These bits setup the required operating mode for the TM. To ensure reliable operation
the TM should be switched off before any changes are made to the bits. In the Timer/
Counter Mode, the TM output pin control must be disabled.
Bit 5 ~ 4CTIO1~CTIO0: Select CTM output function
Compare Match Output Mode
00: No change
01: Output low
10: Output high
11: Toggle output
PWM Mode
00: PWM output inactive state
01: PWM output active state
10: PWM output
11: Undefined
Timer/counter Mode
Unused
These two bits are used to determine how the TM output pin changes state when a
certain condition is reached. The function that these bits select depends upon in which
mode the TM is running.
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In the Compare Match Output Mode, the CTIO1~CTIO0 bits determine how the TM
output pin changes state when a compare match occurs from the Comparator A. The
TM output pin can be setup to switch high, switch low or to toggle its present state
when a compare match occurs from the Comparator A. When the CTIO1~CTIO0 bits
are both zero, then no change will take place on the output. The initial value of the TM
output pin should be setup using the CTOC bit. Note that the output level requested by
the CTIO1~CTIO0 bits must be different from the initial value setup using the CTOC
bit otherwise no change will occur on the TM output pin when a compare match
occurs. After the TM output pin changes state it can be reset to its initial level by
changing the level of the CTON bit from low to high.
In the PWM Mode, the CTIO1 and CTIO0 bits determine how the TM output pin
changes state when a certain compare match condition occurs. The PWM output
function is modified by changing these two bits. It is necessary to change the values
of the CTIO1 and CTIO0 bits only after the TM has been switched off. Unpredictable
PWM outputs will occur if the CTIO1 and CTIO0 bits are changed when the TM is
running.
Bit 3CTOC: CTM Output control bit
Compare Match Output Mode
0: Initial low
1: Initial high
PWM Mode
0: Active low
1: Active high
This is the output control bit for the TM output pin. Its operation depends upon
whether TM is being used in the Compare Match Output Mode or in the PWM Mode.
It has no effect if the TM is in the Timer/Counter Mode. In the Compare Match Output
Mode it determines the logic level of the TM output pin before a compare match
occurs. In the PWM Mode it determines if the PWM signal is active high or active
low.
Bit 2CTPOL: CTM Output polarity Control
0: Non-invert
1: Invert
This bit controls the polarity of the TM output pin. When the bit is set high the TM
output pin will be inverted and not inverted when the bit is zero. It has no effect if the
TM is in the Timer/Counter Mode.
Bit 1CTDPX: CTM PWM period/duty Control
0: CCRP - period; CCRA - duty
1: CCRP - duty; CCRA - period
This bit, determines which of the CCRA and CCRP registers are used for period and
duty control of the PWM waveform.
Bit 0CTCCLR: Select CTM Counter clear condition
0: CTM Comparatror P match
1: CTM Comparatror A match
This bit is used to select the method which clears the counter. Remember that the
Compact TM contains two comparators, Comparator A and Comparator P, either of
which can be selected to clear the internal counter. With the CTCCLR bit set high,
the counter will be cleared when a compare match occurs from the Comparator A.
When the bit is low, the counter will be cleared when a compare match occurs from
the Comparator P or with a counter overflow. A counter overflow clearing method can
only be implemented if the CCRP bits are all cleared to zero. The CTCCLR bit is not
used in the PWM Mode.
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CTMDL Register
Bit
7
6
5
4
3
2
1
0
Name
D7
D6
D5
D4
D3
D2
D1
D0
R/W
R
R
R
R
R
R
R
R
POR
0
0
0
0
0
0
0
0
Bit 7 ~ 0D7~D0: CTM Counter Low Byte Register bit 7 ~ bit 0
CTM 10-bit Counter bit 7 ~ bit 0
CTMDH Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
—
—
D9
D8
R/W
—
—
—
—
—
—
R
R
POR
—
—
—
—
—
—
0
0
Bit 7 ~ 2
Unimplemented, read as “0”
Bit 1 ~ 0D9~D8: CTM Counter High Byte Register bit 1 ~ bit 0
CTM 10-bit Counter bit 9 ~ bit 8
CTMAL Register
Bit
7
6
5
4
3
2
1
0
Name
D7
D6
D5
D4
D3
D2
D1
D0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7 ~ 0D7~D0: CTM CCRA Low Byte Register bit 7 ~ bit 0
CTM 10-bit CCRA bit 7 ~ bit 0
CTMAH Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
—
—
D9
D8
R/W
—
—
—
—
—
—
R/W
R/W
POR
—
—
—
—
—
—
0
0
Bit 7 ~ 2
Unimplemented, read as “0”
Bit 1 ~ 0D9~D8: CTM CCRA High Byte Register bit 1 ~ bit 0
CTM 10-bit CCRA bit 9 ~ bit 8
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Compact Type TM Operating Modes
The Compact Type TM can operate in one of three operating modes, Compare Match Output Mode,
PWM Output Mode or Timer/Counter Mode. The operating mode is selected using the CTM1 and
CTM0 bits in the CTMC1 register.
Compare Match Output Mode
To select this mode, bits CTM1 and CTM0 in the CTMC1 register, should be set to 00 or 01
respectively. In this mode once the counter is enabled and running it can be cleared by three
methods. These are a counter overflow, a compare match from Comparator A and a compare match
from Comparator P. When the CTCCLR bit is low, there are two ways in which the counter can be
cleared. One is when a compare match from Comparator P, the other is when the CCRP bits are all
zero which allows the counter to overflow. Here both CTMAF and CTMPF interrupt request flags
for Comparator A and Comparator P respectively, will both be generated.
If the CTCCLR bit in the CTMC1 register is high then the counter will be cleared when a compare
match occurs from Comparator A. However, here only the CTMAF interrupt request flag will be
generated even if the value of the CCRP bits is less than that of the CCRA registers. Therefore when
CTCCLR is high no CTMPF interrupt request flag will be generated. If the CCRA bits are all zero,
the counter will overflow when its reaches its maximum 10-bit, 3FF Hex, value, however here the
CTMAF interrupt request flag will not be generated.
As the name of the mode suggests, after a comparison is made, the TM output pin, will change
state. The TM output pin condition however only changes state when a CTMAF interrupt request
flag is generated after a compare match occurs from Comparator A. The CTMPF interrupt request
flag, generated from a compare match occurs from Comparator P, will have no effect on the TM
output pin. The way in which the TM output pin changes state are determined by the condition of
the CTIO1 and CTIO0 bits in the CTMC1 register. The TM output pin can be selected using the
CTIO1 and CTIO0 bits to go high, to go low or to toggle from its present condition when a compare
match occurs from Comparator A. The initial condition of the TM output pin, which is setup after
the CTON bit changes from low to high, is setup using the CTOC bit. Note that if the CTIO1 and
CTIO0 bits are zero then no pin change will take place.
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A/D 8-Bit Flash MCU with EEPROM
Counter Value
0x3FF
CTCCLR = 0; CTM[1:0] = 00 / 01
Counter
overflow
CCRP > 0
Counter cleared by CCRP value
CCRP = 0
Counter
Reset
Resume
CCRP > 0
CCRP
Pause
CCRA
Stop
Time
CTON
CTPAU
CTPOL
CCRP Int.
Flag CTMPF
CCRA Int.
Flag CTMAF
CTM O/P Pin
Output Pin set
to Initial Level
Low if CTOC = 0
Output Toggle
with CTMAF flag
Now CTIO[1:0] = 10
Active High Output Select
Output not affected by
CTMAF flag. Remains High
until reset by CTON bit
Output inverts
when CTPOL is high
Output Pin
Reset to initial value
un-defined
Here CTIO[1:0] = 11
Toggle Output Select
Compare Match Output Mode – CTCCLR = 0
Note: 1. With CTCCLR = 0, a Comparator P match will clear the counter
2. The TM output pin controlled only by the CTMAF flag
3. The output pin reset to initial state by a CTON bit rising edge
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CTCCLR = 1; CTM[1:0] = 00 / 01
Counter Value
CCRA > 0
Counter cleared by CCRA value
0x3FF
Resume
CCRA
Pause
CCRP
CCRA = 0
Counter overflow
CCRA = 0
Stop
Counter Reset
Time
CTON
CTPAU
CTPOL
No CTMAF flag
generated on
CCRA overflow
CCRA Int.
Flag CTMAF
CCRP Int.
Flag CTMPF
CTM O/P Pin
Output does
not change
CTMPF not
generated
Output not affected by
Output Pin set
to Initial Level
Low if CTOC = 0
Output Toggle
with CTMAF flag
Output inverts
when CTPOL is high
Output Pin
Reset to initial value
CTMAF flag. Remains High
Now CTIO[1:0] = 10
Active High Output Select
until reset by CTON bit
un-defined
Here CTIO[1:0] = 11
Toggle Output Select
Compare Match Output Mode – CTCCLR = 1
Note: 1. With CTCCLR = 1, a Comparator A match will clear the counter
2. The TM output pin controlled only by the CTMAF flag
3. The output pin reset to initial state by a CTON rising edge
4. The CTMPF flags is not generated when CTCCLR = 1
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Timer/Counter Mode
To select this mode, bits CTM1 and CTM0 in the CTMC1 register should be set to 11 respectively.
The Timer/Counter Mode operates in an identical way to the Compare Match Output Mode
generating the same interrupt flags. The exception is that in the Timer/Counter Mode the TM output
pin is not used. Therefore the above description and Timing Diagrams for the Compare Match
Output Mode can be used to understand its function. As the TM output pin is not used in this mode,
the pin can be used as a normal I/O pin or other pin-shared function.
PWM Output Mode
To select this mode, bits CTM1 and CTM0 in the CTMC1 register should be set to 10 respectively.
The PWM function within the TM is useful for applications which require functions such as motor
control, heating control, illumination control etc. By providing a signal of fixed frequency but
of varying duty cycle on the TM output pin, a square wave AC waveform can be generated with
varying equivalent DC RMS values.
As both the period and duty cycle of the PWM waveform can be controlled, the choice of generated
waveform is extremely flexible. In the PWM mode, the CTCCLR bit has no effect as the PWM
period. Both of the CCRA and CCRP registers are used to generate the PWM waveform, one register
is used to clear the internal counter and thus control the PWM waveform frequency, while the other
one is used to control the duty cycle. Which register is used to control either frequency or duty cycle
is determined using the CTDPX bit in the CTMC1 register. The PWM waveform frequency and duty
cycle can therefore be controlled by the values in the CCRA and CCRP registers.
An interrupt flag, one for each of the CCRA and CCRP, will be generated when a compare match
occurs from either Comparator A or Comparator P. The CTOC bit In the CTMC1 register is used to
select the required polarity of the PWM waveform while the two CTIO1 and CTIO0 bits are used to
enable the PWM output or to force the TM output pin to a fixed high or low level. The CTPOL bit is
used to reverse the polarity of the PWM output waveform.
• CTM, PWM Mode, Edge-aligned Mode, CTDPX=0
CCRP
001b
010b
011b
100b
101b
110b
111b
000b
Period
128
256
384
512
640
768
896
1024
Duty
CCRA
If fSYS = 16MHz, TM clock source is fSYS/4, CCRP = 100b, CCRA =128,
The CTM PWM output frequency = (fSYS/4) /512 = fSYS/2048 = 7.8125 kHz, duty = 128/512 = 25%.
If the Duty value defined by the CCRA register is equal to or greater than the Period value, then the
PWM output duty is 100%.
• CTM, PWM Mode, Edge-aligned Mode, CTDPX=1
CCRP
001b
010b
011b
100b
Period
Duty
101b
110b
111b
000b
768
896
1024
CCRA
128
256
384
512
640
The PWM output period is determined by the CCRA register value together with the TM clock
while the PWM duty cycle is defined by the CCRP register value.
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A/D 8-Bit Flash MCU with EEPROM
Counter
Value
CTDPX=0;CTM[1:0]=10
Counter Cleared by CCRP
Counter reset when
CTON returns high
CCRP
Counter stop if
CTON bit low
Pause Resume
CCRA
Time
CTON
CTPAU
CTPOL
CCRA Int.
Flag CTMAF
CCRP Int.
Flag CTMPF
CTM O/P Pin
(CTOC=1)
CTM O/P Pin
(CTOC=0)
PWM Duty Cycle
set by CCRA
un-defined
PWM resumes
operation
Output Inverts
When CTPOL = 1
PWM Period
set by CCRP
PWM Mode – CTDPX = 0
Note: 1. Here CTDPX = 0 - Counter cleared by CCRP
2. A counter clear sets PWM Period
3. The internal PWM function continues running even when CTIO[1:0] = 00 or 01
4. The CTCCLR bit has no influence on PWM operation
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A/D 8-Bit Flash MCU with EEPROM
Counter
Value
CTDPX=1;CTM[1:0]=10
Counter Cleared by CCRA
Counter reset when
CTON returns high
CCRA
Counter stop if
CTON bit low
Pause Resume
CCRP
Time
CTON
CTPAU
CTPOL
CCRP Int.
Flag CTMPF
CCRA Int.
Flag CTMAF
CTM O/P Pin
(CTOC=1)
CTM O/P Pin
(CTOC=0)
PWM Duty Cycle
set by CCRP
un-defined
PWM
resumes
operation
Output Inverts
When CTPOL = 1
PWM Period
set by CCRA
PWM Mode – CTDPX = 1
Note: 1. Here CTDPX = 1 - Counter cleared by CCRA
2. A counter clear sets PWM Period
3. The internal PWM function continues even when CTIO[1:0] = 00 or 01
4. The CTCCLR bit has no influence on PWM operation
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A/D 8-Bit Flash MCU with EEPROM
Standard Type TM – STM
The Standard Type TM contains five operating modes, which are Compare Match Output, Timer/
Event Counter, Capture Input, Single Pulse Output and PWM Output modes. The Standard TM can
drive one external output pin.
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‚   Standard Type TM Block Diagram
Standard TM Operation
At its core is a 16-bit count-up counter which is driven by a user selectable internal clock source.
There are also two internal comparators with the names, Comparator A and Comparator P. These
comparators will compare the value in the counter with CCRP and CCRA registers. The CCRP is 8-bit
wide whose value is compared with the highest 8 bits in the counter while the CCRA is 16 bits and
therefore compares with all counter bits.
The only way of changing the value of the 16-bit counter using the application program, is to
clear the counter by changing the STON bit from low to high. The counter will also be cleared
automatically by a counter overflow or a compare match with one of its associated comparators.
When these conditions occur, a TM interrupt signal will also usually be generated. The Standard
Type TM can operate in a number of different operational modes, can be driven by different clock
sources including an input pin and can also control an output pin. All operating setup conditions are
selected using relevant internal registers.
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Standard Type TM Register Description
Overall operation of the Standard TM is controlled using series of registers. A read only register
pair exists to store the internal counter 16-bit value, while a read/write register pair exists to store
the internal 16-bit CCRA value. The remaining two registers are control registers which setup the
different operating and control modes as well as eight CCRP bits.
Bit
Register
Name
7
6
5
4
3
2
1
0
STMC0
STPAU
STCK2
STCK1
STCK0
STON
—
—
—
STMC1
STM1
STM0
STIO1
STIO0
STOC
STPOL
STDPX
STCCLR
STMDL
D7
D6
D5
D4
D3
D2
D1
D0
STMDH
D15
D14
D13
D12
D11
D10
D9
D8
STMAL
D7
D6
D5
D4
D3
D2
D1
D0
STMAH
D15
D14
D13
D12
D11
D10
D9
D8
STMRP
D7
D6
D5
D4
D3
D2
D1
D0
2
1
0
16-bit Standard TM Register List
STMC0 Register
Bit
7
6
5
4
3
Name
STPAU
STCK2
STCK1
STCK0
STON
—
—
—
R/W
R/W
R/W
R/W
R/W
R/W
—
—
—
POR
0
0
0
0
0
—
—
—
Bit 7STPAU: STM Counter Pause Control
0: Run
1: Pause
The counter can be paused by setting this bit high. Clearing the bit to zero restores
normal counter operation. When in a Pause condition the TM will remain powered up
and continue to consume power. The counter will retain its residual value when this bit
changes from low to high and resume counting from this value when the bit changes
to a low value again.
Bit 6 ~ 4
STCK2 ~ STCK0: Select STM Counter clock
000: fSYS/4
001: fSYS
010: fH/16
011: fH/64
100: fTBC
101: fTBC
110: STCK rising edge clock
111: STCK falling edge clock
These three bits are used to select the clock source for the TM. The external pin clock
source can be chosen to be active on the rising or falling edge. The clock source fSYS is
the system clock, while fH and fTBC are other internal clocks, the details of which can
be found in the oscillator section.
Bit 3STON: STM Counter On/Off Control
0: Off
1: On
This bit controls the overall on/off function of the TM. Setting the bit high enables the
counter to run, clearing the bit disables the TM. Clearing this bit to zero will stop the
counter from counting and turn off the TM which will reduce its power consumption.
When the bit changes state from low to high the internal counter value will be reset to
zero, however when the bit changes from high to low, the internal counter will retain
its residual value until the bit returns high again.
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If the TM is in the Compare Match Output Mode then the TM output pin will be reset
to its initial condition, as specified by the STOC bit, when the STON bit changes from
low to high.
Bit 2 ~ 0
Unimplemented, read as “0”
STMC1 Register
Bit
7
6
5
4
3
2
1
0
Name
STM1
STM0
STIO1
STIO0
STOC
STPOL
STDPX
STCCLR
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7 ~ 6STM1~STM0: Select STM Operating Mode
00: Compare Match Output Mode
01: Capture Input Mode
10: PWM Mode or Single Pulse Output Mode
11: Timer/Counter Mode
These bits setup the required operating mode for the TM. To ensure reliable operation
the TM should be switched off before any changes are made to the bits. In the Timer/
Counter Mode, the TM output pin control must be disabled.
Bit 5 ~ 4STIO1~STIO0: Select STM output function
Compare Match Output Mode
00: No change
01: Output low
10: Output high
11: Toggle output
PWM Mode/Single Pulse Output Mode
00: PWM output inactive state
01: PWM output active state
10: PWM output
11: Single pulse output
Capture Input Mode
00: Input capture at rising edge of STP
01: Input capture at falling edge of STP
10: Input capture at falling/rising edge of STP
11: Input capture disabled
Timer/counter Mode
Unused
These two bits are used to determine how the TM output pin changes state when a
certain condition is reached. The function that these bits select depends upon in which
mode the TM is running.
In the Compare Match Output Mode, the STIO1~STIO0 bits determine how the TM
output pin changes state when a compare match occurs from the Comparator A. The
TM output pin can be setup to switch high, switch low or to toggle its present state
when a compare match occurs from the Comparator A. When the STIO1~STIO0 bits
are both zero, then no change will take place on the output. The initial value of the TM
output pin should be setup using the STOC bit. Note that the output level requested by
the STIO1~STIO0 bits must be different from the initial value setup using the STOC
bit otherwise no change will occur on the TM output pin when a compare match
occurs. After the TM output pin changes state it can be reset to its initial level by
changing the level of the STON bit from low to high.
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In the PWM Mode, the STIO1 and STIO0 bits determine how the TM output pin
changes state when a certain compare match condition occurs. The PWM output
function is modified by changing these two bits. It is necessary to change the values
of the STIO1 and STIO0 bits only after the TM has been switched off. Unpredictable
PWM outputs will occur if the STIO1 and STIO0 bits are changed when the TM is
running.
Bit 3STOC: STM Output control bit
Compare Match Output Mode
0: Initial low
1: Initial high
PWM Mode/Single Pulse Output Mode
0: Active low
1: Active high
This is the output control bit for the TM output pin. Its operation depends upon
whether TM is being used in the Compare Match Output Mode or in the PWM Mode/
Single Pulse Output Mode. It has no effect if the TM is in the Timer/Counter Mode. In
the Compare Match Output Mode it determines the logic level of the TM output pin
before a compare match occurs. In the PWM Mode it determines if the PWM signal is
active high or active low.
Bit 2STPOL: STM Output polarity Control
0: Non-invert
1: Invert
This bit controls the polarity of the TM output pin. When the bit is set high the TM
output pin will be inverted and not inverted when the bit is zero. It has no effect if the
TM is in the Timer/Counter Mode.
Bit 1STDPX: STM PWM period/duty Control
0: CCRP - period; CCRA - duty
1: CCRP - duty; CCRA - period
This bit, determines which of the CCRA and CCRP registers are used for period and
duty control of the PWM waveform.
Bit 0STCCLR: Select STM Counter clear condition
0: TM Comparator P match
1: TM Comparator A match
This bit is used to select the method which clears the counter. Remember that the
Standard TM contains two comparators, Comparator A and Comparator P, either of
which can be selected to clear the internal counter. With the STCCLR bit set high,
the counter will be cleared when a compare match occurs from the Comparator A.
When the bit is low, the counter will be cleared when a compare match occurs from
the Comparator P or with a counter overflow. A counter overflow clearing method can
only be implemented if the CCRP bits are all cleared to zero. The STCCLR bit is not
used in the PWM, Single Pulse or Input Capture Mode.
Rev. 1.00
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A/D 8-Bit Flash MCU with EEPROM
STMDL Register
Bit
7
6
5
4
3
2
1
0
Name
D7
D6
D5
D4
D3
D2
D1
D0
R/W
R
R
R
R
R
R
R
R
POR
0
0
0
0
0
0
0
0
Bit 7 ~ 0D7~D0: STM Counter Low Byte Register bit 7 ~ bit 0
STM 16-bit Counter bit 7 ~ bit 0
STMDH Register
Bit
7
6
5
4
3
2
1
0
Name
D15
D14
D13
D12
D11
D10
D9
D8
R/W
R
R
R
R
R
R
R
R
POR
0
0
0
0
0
0
0
0
2
1
0
Bit 7 ~ 0D15~D8: STM Counter High Byte Register bit 7 ~ bit 0
STM 16-bit Counter bit 15 ~ bit 8
STMAL Register
Bit
7
6
5
4
3
Name
D7
D6
D5
D4
D3
D2
D1
D0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7 ~ 0D7~D0: STM CCRA Low Byte Register bit 7 ~ bit 0
STM 16-bit CCRA bit 7 ~ bit 0
STMAH Register
Bit
7
6
5
4
3
2
1
0
Name
D15
D14
D13
D12
D11
D10
D9
D8
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7 ~ 0D15~D8: STM CCRA High Byte Register bit 7 ~ bit 0
STM 16-bit CCRA bit 15 ~ bit 8
STMRP Register
Bit
7
6
5
4
3
2
1
0
Name
D7
D6
D5
D4
D3
D2
D1
D0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7 ~ 0STMRP: STM CCRP High Byte Register bit 7 ~ bit 0
STM CCRP 8-bit register, compared with the STM Counter bit 15 ~ bit 8. Comparator P
Match Period
0: 65536 STM clocks
1~255: 256 × (1~255) STM clocks
These eight bits are used to setup the value on the internal CCRP 8-bit register, which
are then compared with the internal counter's highest eight bits. The result of this
comparison can be selected to clear the internal counter if the STCCLR bit is set to
zero. Setting the STCCLR bit to zero ensures that a compare match with the CCRP
values will reset the internal counter. As the CCRP bits are only compared with the
highest eight counter bits, the compare values exist in 256 clock cycle multiples.
Clearing all eight bits to zero is in effect allowing the counter to overflow at its
maximum value.
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Standard Type TM Operating Modes
The Standard Type TM can operate in one of five operating modes, Compare Match Output Mode,
PWM Output Mode, Single Pulse Output Mode, Capture Input Mode or Timer/Counter Mode. The
operating mode is selected using the STM1 and STM0 bits in the STMC1 register.
Compare Match Output Mode
To select this mode, bits STM1 and STM0 in the STMC1 register, should be set to 00 respectively.
In this mode once the counter is enabled and running it can be cleared by three methods. These are
a counter overflow, a compare match from Comparator A and a compare match from Comparator P.
When the STCCLR bit is low, there are two ways in which the counter can be cleared. One is when
a compare match from Comparator P, the other is when the CCRP bits are all zero which allows the
counter to overflow. Here both STMAF and STMPF interrupt request flags for Comparator A and
Comparator P respectively, will both be generated.
If the STCCLR bit in the STMC1 register is high then the counter will be cleared when a compare
match occurs from Comparator A. However, here only the STMAF interrupt request flag will be
generated even if the value of the CCRP bits is less than that of the CCRA registers. Therefore when
STCCLR is high no STMPF interrupt request flag will be generated. In the Compare Match Output
Mode, the CCRA can not be set to “0”.
As the name of the mode suggests, after a comparison is made, the TM output pin, will change state.
The TM output pin condition however only changes state when a STMAF interrupt request flag is
generated after a compare match occurs from Comparator A. The STMPF interrupt request flag,
generated from a compare match occurs from Comparator P, will have no effect on the TM output
pin. The way in which the TM output pin changes state are determined by the condition of the
STIO1 and STIO0 bits in the STMC1 register. The TM output pin can be selected using the STIO1
and STIO0 bits to go high, to go low or to toggle from its present condition when a compare match
occurs from Comparator A. The initial condition of the TM output pin, which is setup after the
STON bit changes from low to high, is setup using the STOC bit. Note that if the STIO1 and STIO0
bits are zero then no pin change will take place.
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A/D 8-Bit Flash MCU with EEPROM
Counter Value
0xFFFF
STCCLR = 0; STM[1:0] = 00
Counter
overflow
CCRP > 0
Counter cleared by CCRP value
CCRP = 0
Counter
Reset
Resume
CCRP > 0
CCRP
Pause
CCRA
Stop
Time
STON
STPAU
STPOL
CCRP Int.
Flag STMPF
CCRA Int.
Flag STMAF
STM O/P Pin
Output Pin set
to Initial Level
Low if STOC = 0
Output Toggle
with STMAF flag
Now STIO[1:0] = 10
Active High Output Select
Output not affected by
STMAF flag. Remains High
until reset by STON bit
Output inverts
when STPOL is high
Output Pin
Reset to initial value
Output controlled
by other pin - shared function
Here STIO[1:0] = 11
Toggle Output Select
Compare Match Output Mode – STCCLR = 0
Note: 1. With STCCLR = 0 a Comparator P match will clear the counter
2. The TM output pin controlled only by the STMAF flag
3. The output pin reset to initial state by a STON bit rising edge
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STCCLR = 1; STM[1:0] = 00
Counter Value
CCRA > 0
Counter cleared by CCRA value
0xFFFF
Resume
CCRA
Pause
CCRP
CCRA = 0
Counter overflow
CCRA = 0
Stop
Counter Reset
Time
STON
STPAU
STPOL
No STMAF flag
generated on
CCRA overflow
CCRP Int.
Flag STMAF
CCRA Int.
Flag STMPF
STM O/P Pin
Output does
not change
STMPF not
generated
Output not affected by
Output Pin set
to Initial Level
Low if STOC = 0
Output Toggle
with STMAF flag
STMAF flag. Remains High
Now STIO[1:0] = 10
Active High Output Select
until reset by STON bit
Here STIO[1:0] = 11
Toggle Output Select
Output inverts
when STPOL is high
Output Pin
Reset to initial value
Output controlled
by other pin shared
function
-
Compare Match Output Mode – STCCLR = 1
Note: 1. With STCCLR = 1 a Comparator A match will clear the counter
2. The TM output pin controlled only by the STMAF flag
3. The output pin reset to initial state by a STON rising edge
4. The STMPF flags is not generated when STCCLR = 1
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Timer/Counter Mode
To select this mode, bits STM1 and STM0 in the STMC1 register should be set to 11 respectively.
The Timer/Counter Mode operates in an identical way to the Compare Match Output Mode
generating the same interrupt flags. The exception is that in the Timer/Counter Mode the TM output
pin is not used. Therefore the above description and Timing Diagrams for the Compare Match
Output Mode can be used to understand its function. As the TM output pin is not used in this mode,
the pin can be used as a normal I/O pin or other pin-shared function.
PWM Output Mode
To select this mode, bits STM1 and STM0 in the STMC1 register should be set to 10 respectively
and also the STIO1 and STIO0 bits should be set to 10 respectively. The PWM function within
the TM is useful for applications which require functions such as motor control, heating control,
illumination control etc. By providing a signal of fixed frequency but of varying duty cycle on the
TM output pin, a square wave AC waveform can be generated with varying equivalent DC RMS
values.
As both the period and duty cycle of the PWM waveform can be controlled, the choice of generated
waveform is extremely flexible. In the PWM mode, the STCCLR bit has no effect as the PWM
period. Both of the CCRA and CCRP registers are used to generate the PWM waveform, one register
is used to clear the internal counter and thus control the PWM waveform frequency, while the other
one is used to control the duty cycle. Which register is used to control either frequency or duty cycle
is determined using the STDPX bit in the STMC1 register.
The PWM waveform frequency and duty cycle can therefore be controlled by the values in the
CCRA and CCRP registers. An interrupt flag, one for each of the CCRA and CCRP, will be
generated when a compare match occurs from either Comparator A or Comparator P. The STOC bit
In the STMC1 register is used to select the required polarity of the PWM waveform while the two
STIO1 and STIO0 bits are used to enable the PWM output or to force the TM output pin to a fixed
high or low level. The STPOL bit is used to reverse the polarity of the PWM output waveform.
• 16-bit STM, PWM Mode, Edge-aligned Mode, STDPX=0
CCRP
1~255
0
Period
CCRP×256
65536
Duty
CCRA
If fSYS = 16MHz, TM clock source is fSYS/4, CCRP = 2 and CCRA =128,
The STM PWM output frequency = (fSYS/4) /512 = fSYS/2048 = 7.8125 kHz, duty = 128/512 = 25%.
If the Duty value defined by the CCRA register is equal to or greater than the Period value, then the
PWM output duty is 100%.
• 16-bit STM, PWM Mode, Edge-aligned Mode, STDPX=1
CCRP
1~255
Period
Duty
0
CCRA
CCRP×256
65536
The PWM output period is determined by the CCRA register value together with the TM clock
while the PWM duty cycle is defined by the (CCRP×256) except when the CCRP value is equal to 0.
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Counter
Value
STDPX=0;STM[1:0]=10
Counter Cleared by CCRP
Counter reset when
STON returns high
CCRP
Pause Resume
CCRA
Counter Stop If
STON bit low
Time
STON
STPAU
STPOL
CCRA Int.
Flag STMAF
CCRP Int.
Flag STMPF
STM O/P Pin
(STOC=1)
STM O/P Pin
(STOC=0)
PWM Duty Cycle
set by CCRA
Output controlled by
Other pin-shared function
PWM resumes
operation
Output Inverts
When STPOL = 1
PWM Period
set by CCRP
PWM Mode – STDPX=0
Note: 1. Here STDPX = 0 - Counter cleared by CCRP
2. A counter clear sets PWM Period
3. The internal PWM function continues running even when STIO[1:0] = 00 or 01
4. The STCCLR bit has no influence on PWM operation
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Counter
Value
STDPX=1;STM[1:0]=10
Counter Cleared by CCRA
Counter reset when
STON returns high
CCRA
Pause Resume
CCRP
Counter Stop If
STON bit low
Time
STON
STPAU
STPOL
CCRP Int.
Flag STMPF
CCRA Int.
Flag STMAF
STM O/P Pin
(STOC=1)
STM O/P Pin
(STOC=0)
PWM Duty Cycle
set by CCRP
Output controlled by
Other pin-shared function
PWM resumes
operation
Output Inverts
When STPOL = 1
PWM Period
set by CCRA
PWM Mode – STDPX=1
Note: 1. Here STDPX = 1 - Counter cleared by CCRA
2. A counter clear sets PWM Period
3. The internal PWM function continues even when STIO[1:0] = 00 or 01
4. The STCCLR bit has no influence on PWM operation
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Single Pulse Mode
To select this mode, bits STM1 and STM0 in the STMC1 register should be set to 10 respectively
and also the STIO1 and STIO0 bits should be set to 11 respectively. The Single Pulse Output Mode,
as the name suggests, will generate a single shot pulse on the TM output pin.
The trigger for the pulse output leading edge is a low to high transition of the STON bit, which can
be implemented using the application program. However in the Single Pulse Mode, the STON bit
can also be made to automatically change from low to high using the external STCK pin, which will
in turn initiate the Single Pulse output.
When the STON bit transitions to a high level, the counter will start running and the pulse leading
edge will be generated. The STON bit should remain high when the pulse is in its active state. The
generated pulse trailing edge will be generated when the STON bit is cleared to zero, which can be
implemented using the application program or when a compare match occurs from Comparator A.
            Single Pulse Generation
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Counter Value
STM [1:0] = 10 ; STIO [1:0] = 11
Counter stopped
by CCRA
Counter Reset when
STON returns high
CCRA
Pause
Counter Stops
by software
Resume
CCRP
Time
STON
Software
Trigger
Auto. set by
STCK pin
Cleared by
CCRA match
STCK pin
Software
Trigger
Software
Clear
Software
Trigger
Software
Trigger
STCK pin
Trigger
STPAU
STPOL
No CCRP Interrupts
generated
CCRP Int. Flag
STMPF
CCRA Int. Flag
STMAF
STM O/P Pin
(STOC=1)
STM O/P Pin
(STOC=0)
Output Inverts
when STPOL = 1
Pulse Width
set by CCRA
Single Pulse Mode
Note: 1. Counter stopped by CCRA match
2. CCRP is not used
3. The pulse is triggered by setting the STON bit high or STCK pin
4. In the Single Pulse Mode, STIO [1:0] must be set to “11” and can not be changed.
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However a compare match from Comparator A will also automatically clear the STON bit and thus
generate the Single Pulse output trailing edge. In this way the CCRA value can be used to control
the pulse width. A compare match from Comparator A will also generate a TM interrupt. The counter
can only be reset back to zero when the STON bit changes from low to high when the counter
restarts. In the Single Pulse Mode CCRP is not used. The STCCLR and STDPX bits are not used in
this Mode.
Capture Input Mode
To select this mode bits STM1 and STM0 in the STMC1 register should be set to 01 respectively.
This mode enables external signals to capture and store the present value of the internal counter
and can therefore be used for applications such as pulse width measurements. The external signal is
supplied on the STP pin, whose active edge can be either a rising edge, a falling edge or both rising
and falling edges; the active edge transition type is selected using the STIO1 and STIO0 bits in
the STMC1 register. The counter is started when the STON bit changes from low to high which is
initiated using the application program.
When the required edge transition appears on the STP pin the present value in the counter will be
latched into the CCRA registers and a TM interrupt generated. Irrespective of what events occur on
the STP pin the counter will continue to free run until the STON bit changes from high to low. When
a CCRP compare match occurs the counter will reset back to zero; in this way the CCRP value
can be used to control the maximum counter value. When a CCRP compare match occurs from
Comparator P, a TM interrupt will also be generated. Counting the number of overflow interrupt
signals from the CCRP can be a useful method in measuring long pulse widths. The STIO1 and
STIO0 bits can select the active trigger edge on the STP pin to be a rising edge, falling edge or both
edge types. If the STIO1 and STIO0 bits are both set high, then no capture operation will take place
irrespective of what happens on the STP pin, however it must be noted that the counter will continue
to run.
As the STP pin is pin shared with other functions, care must be taken if the TM is in the Input
Capture Mode. This is because if the pin is setup as an output, then any transitions on this pin may
cause an input capture operation to be executed. The STCCLR and STDPX bits are not used in this
Mode.
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Counter Value
STM [1:0] = 01
Counter cleared
by CCRP
Counter Counter
Reset
Stop
CCRP
YY
Pause
Resume
XX
Time
STON
STPAU
Active
edge
Active
edge
Active edge
STM capture pin
STP
CCRA Int. Flag
STMAF
CCRP Int. Flag
STMPF
CCRA
Value
STIO [1:0]
Value
XX
00 – Rising edge
YY
01 – Falling edge
XX
10 – Both edges
YY
11 – Disable Capture
Capture Input Mode
Note: 1. STM[1:0] = 01 and active edge set by the STIO[1:0] bits
2. A TM Capture input pin active edge transfers the counter value to CCRA
3. The STCCLR bit is not used
4. No output function - STOC and STPOL bits are not used
5. CCRP determines the counter value and the counter has a maximum count value when CCRP is equal to
zero.
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Periodic Type TM – PTM0, PTM1
The PTM contains five operating modes, which are Compare Match Output, Timer/Event Counter,
Capture Input, Single Pulse Output and PWM Output modes. The P-type TM can also be controlled
with an external input pin and can drive one output pins.
Periodic TM Operation
There are two P-type TMs, both are 10-bit wide. At the core is a 10 count-up counter which is
driven by a user selectable internal or external clock source. There are also two internal comparators
with the names, Comparator A and Comparator P. These comparators will compare the value in the
counter with CCRP and CCRA registers. The CCRP comparator is 10-bits wide.
The only way of changing the value of the 10 counter using the application program, is to clear the
counter by changing the PTnON bit from low to high. The counter will also be cleared automatically
by a counter overflow or a compare match with one of its associated comparators. When these
conditions occur, a TM interrupt signal will also usually be generated. The Periodic Type TM
can operate in a number of different operational modes, can be driven by different clock sources
including an input pin and can also control an output pin. All operating setup conditions are selected
using relevant internal registers.
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Periodic Type TM Block Diagram (n=0, 1)
Rev. 1.00
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PTM register description
Overall operation of the P-type TM is controlled using a series of registers. A read only register pair
exists to store the internal counter 10-bit value, while two read/write register pairs exist to store the
internal 10-bit CCRA/CCRP value. The remaining two registers are control registers which setup the
different operating and control modes.
Bit
Register
Name
7
6
5
4
3
2
1
0
PTMnC0
PTnPAU
PTnCK2
PTnCK1
PTnCK0
PTnON
—
—
—
PTMnC1
PTnM1
PTnM0
PTnIO1
PTnIO0
PTnOC
PTMnDL
D7
D6
D5
D4
D3
D2
D1
D0
PTMnDH
—
—
—
—
—
—
D9
D8
PTMnAL
D7
D6
D5
D4
D3
D2
D1
D0
PTnPOL PTnCKS PTnCCLR
PTMnAH
—
—
—
—
—
—
D9
D8
PTMnRPL
D7
D6
D5
D4
D3
D2
D1
D0
PTMnRPH
—
—
—
—
—
—
D9
D8
10-bit Periodic TM Register List (n=0, 1)
PTMnC0 Register
Bit
7
6
5
4
3
2
1
0
Name
PTnPAU
PTnCK2
PTnCK1
PTnCK0
PTnON
—
—
—
R/W
R/W
R/W
R/W
R/W
R/W
—
—
—
POR
0
0
0
0
0
—
—
—
Bit 7PTnPAU: PTMn Counter Pause Control
0: Run
1: Pause
The counter can be paused by setting this bit high. Clearing the bit to zero restores
normal counter operation. When in a Pause condition the TM will remain powered up
and continue to consume power. The counter will retain its residual value when this bit
changes from low to high and resume counting from this value when the bit changes
to a low value again.
Bit 6 ~4
Rev. 1.00
PTnCK2 ~ PTnCK0: Select PTMn Counter clock
000: fSYS/4
001: fSYS
010: fH/16
011: fH/64
100: fTBC
101: fTBC
110: PTCKn rising edge clock
111: PTCKn falling edge clock
These three bits are used to select the clock source for the TM. The external pin clock
source can be chosen to be active on the rising or falling edge. The clock source fSYS is
the system clock, while fH and fTBC are other internal clocks, the details of which can
be found in the oscillator section.
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Bit 3PTnON: PTMn Counter On/Off Control
0: Off
1: On
This bit controls the overall on/off function of the TM. Setting the bit high enables the
counter to run, clearing the bit disables the TM. Clearing this bit to zero will stop the
counter from counting and turn off the TM which will reduce its power consumption.
When the bit changes state from low to high the internal counter value will be reset to
zero, however when the bit changes from high to low, the internal counter will retain
its residual value until the bit returns high again. If the TM is in the Compare Match
Output Mode then the TM output pin will be reset to its initial condition, as specified
by the PTnOC bit, when the PTnON bit changes from low to high.
Bit 2~0
Unimplemented, read as“0”
PTMnC1 Register
Bit
7
6
5
4
3
2
1
0
Name
PTnM1
PTnM0
PTnIO1
PTnIO0
PTnOC
PTnPOL
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
PTnCKS PTnCCLR
Bit 7~6PTnM1~PTnM0: Select PTMn Operating Mode
00: Compare Match Output Mode
01: Capture Input Mode
10: PWM Mode or Single Pulse Output Mode
11: Timer/Counter Mode
These bits setup the required operating mode for the TM. To ensure reliable operation
the TM should be switched off before any changes are made to the PTnM1 and
PTnM0 bits. In the Timer/Counter Mode, the TM output pin control must be disabled.
Bit 5~4PTnIO1~PTnIO0: Select PTPn output function
Compare Match Output Mode
00: No change
01: Output low
10: Output high
11: Toggle output
PWM Mode/Single Pulse Output Mode
00: Force inactive state
01: Force active state
10: PWM output
11: Single pulse output
Capture Input Mode
00: Input capture at rising edge of PTPn or PTCKn
01: Input capture at falling edge of PTPn or PTCKn
10: Input capture at falling/rising edge of PTPn or PTCKn
11: Input capture disabled
Timer/counter Mode
Unused
These two bits are used to determine how the TM output pin changes state when
a certain condition is reached. The function that these bits select depends upon in
which mode the TM is running. In the Compare Match Output Mode, the PTnIO1 and
PTnIO0 bits determine how the TM output pin changes state when a compare match
occurs from the Comparator A. The TM output pin can be setup to switch high, switch
low or to toggle its present state when a compare match occurs from the Comparator A.
When the bits are both zero, then no change will take place on the output. The initial
value of the TM output pin should be setup using the PTnOC bit in the PTMnC1
register. Note that the output level requested by the PTnIO1 and PTnIO0 bits must be
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different from the initial value setup using the PTnOC bit otherwise no change will
occur on the TM output pin when a compare match occurs. After the TM output pin
changes state it can be reset to its initial level by changing the level of the PTnON bit
from low to high.
Bit 3PTnOC: PTPn Output control bit
Compare Match Output Mode
0: Initial low
1: Initial high
PWM Mode/Single Pulse Output Mode
0: Active low
1: Active high
This is the output control bit for the TM output pin. Its operation depends upon
whether TM is being used in the Compare Match Output Mode or in the PWM Mode/
Single Pulse Output Mode. It has no effect if the TM is in the Timer/Counter Mode. In
the Compare Match Output Mode it determines the logic level of the TM output pin
before a compare match occurs. In the PWM Mode it determines if the PWM signal is
active high or active low.
Bit 2PTnPOL: PTPn Output polarity control
0: Non-invert
1: Invert
This bit controls the polarity of the PTPn output pin. When the bit is set high the TM
output pin will be inverted and not inverted when the bit is zero. It has no effect if the
TM is in theTimer/Counter Mode.
Bit 1PTnCKS: Input Capture trigger source selection
0: External Clock source of Capture Input Mode comes from PTPn
1: External Clock source of Capture Input Mode comes from PTCKn
Bit 0PTnCCLR: Select PTMn Counter clear condition
0: PTMn Comparator P match
1: PTMn Comparator A match
This bit is used to select the method which clears the counter. Remember that the P-type
TM contains two comparators, Comparator A and Comparator P, either of which can
be selected to clear the internal counter. With the PTnCCLR bit set high, the counter
will be cleared when a compare match occurs from the Comparator A. When the bit is
low, the counter will be cleared when a compare match occurs from the Comparator
P or with a counter overflow. A counter overflow clearing method can only be
implemented if the CCRP bits are all cleared to zero. The PTnCCLR bit is not used in
the PWM, Single Pulse or Input Capture Mode.
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PTMnDL Register
Bit
7
6
5
4
3
2
1
0
Name
D7
D6
D5
D4
D3
D2
D1
D0
R/W
R
R
R
R
R
R
R
R
POR
0
0
0
0
0
0
0
0
Bit 7~0D7~D0: PTMn Counter Low Byte Register Bit 7~Bit 0
PTMn 10-bit Counter bit 7 ~ bit 0
PTMnDH Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
—
—
D9
D8
R/W
—
—
—
—
—
—
R
R
POR
—
—
—
—
—
—
0
0
Bit 7~2
Unimplemented, read as“0”
Bit 1~0D9~D8: PTMn Counter High Byte Register Bit 1~Bit 0
PTMn 10-bit Counter bit 9 ~ bit 8
PTMnAL Register
Bit
7
6
5
4
3
2
1
0
Name
D7
D6
D5
D4
D3
D2
D1
D0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7~0D7~D0: PTMn CCRA Low Byte Register bit 7~bit 0
PTMn 10-bit CCRA bit 7~bit 0
PTMnAH Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
—
—
D9
D8
R/W
—
—
—
—
—
—
R/W
R/W
POR
—
—
—
—
—
—
0
0
Bit 7~2
Unimplemented, read as“0”
Bit 1~0D9~D8: PTMn CCRA High Byte Register Bit 1~Bit 0
PTMn 10-bit CCRA bit 9 ~ bit 8
PTMnRPL Register (n=0, 1)
Bit
7
6
5
4
3
2
1
0
Name
D7
D6
D5
D4
D3
D2
D1
D0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7~0D7~D0: PTMn CCRP Register bit 7 ~ bit 0
PTMn 10-bit CCRP bit 7 ~ bit 0
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PTMnRPH Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
—
—
D9
D8
R/W
—
—
—
—
—
—
R/W
R/W
POR
—
—
—
—
—
—
0
0
Bit 7~2
Unimplemented, read as“0”
Bit 1~0D9~D8: PTMn CCRP Register bit 1 ~ bit 0
PTMn 10-bit CCRP bit 9 ~ bit 8
Periodic Type TM Operating Modes
The P-type TM can operate in one of five operating modes, Compare Match Output Mode, PWM
Output Mode, Single Pulse Output Mode, Capture Input Mode or Timer/Counter Mode. The
operating mode is selected using the PTnM1 and PTnM0 bits in the PTMnC1 register.
Compare Output Mode
To select this mode, bits PTnM1 and PTnM0 in the PTMnC1 register, should be set to 00
respectively. In this mode once the counter is enabled and running it can be cleared by three
methods. These are a counter overflow, a compare match from Comparator A and a compare match
from Comparator P. When the PTnCCLR bit is low, there are two ways in which the counter can be
cleared. One is when a compare match from Comparator P, the other is when the CCRP bits are all
zero which allows the counter to overflow. Here both PTMnAF and PTMnPF interrupt request flags
for Comparator A and Comparator P respectively, will both be generated.
If the PTnCCLR bit in the PTMnC1 register is high then the counter will be cleared when a compare
match occurs from Comparator A. However, here only the PTMnAF interrupt request flag will
be generated even if the value of the CCRP bits is less than that of the CCRA registers. Therefore
when PTnCCLR is high no PTMnPF interrupt request flag will be generated. In the Compare Match
Output Mode, the CCRA can not be set to “0”.
As the name of the mode suggests, after a comparison is made, the TM output pin, will change
state. The TM output pin condition however only changes state when a PTMnAF interrupt request
flag is generated after a compare match occurs from Comparator A. The PTMnPF interrupt request
flag, generated from a compare match occurs from Comparator P, will have no effect on the TM
output pin. The way in which the TM output pin changes state are determined by the condition of
the PTnIO1 and PTnIO0 bits in the PTMnC1 register. The TM output pin can be selected using
the PTnIO1 and PTnIO0 bits to go high, to go low or to toggle from its present condition when a
compare match occurs from Comparator A. The initial condition of the TM output pin, which is
setup after the PTnON bit changes from low to high, is setup using the PTnOC bit. Note that if the
PTnIO1 and PTnIO0 bits are zero then no pin change will take place.
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Counter Value
Counter overflow
CCRP=0
0x3FF
PTnCCLR = 0; PTnM [1:0] = 00
CCRP > 0
Counter cleared by CCRP value
CCRP > 0
Counter
Restart
Resume
CCRP
Pause
CCRA
Stop
Time
PTnON
PTnPAU
PTnPOL
CCRP Int. Flag
PTMnPF
CCRA Int. Flag
PTMnAF
PTM O/P
Pin
Output pin set to
initial Level Low
if PTnOC=0
Output not affected by
PTMnAF flag. Remains High
until reset by PTnON bit
Output Toggle with
PTMnAF flag
Here PTnIO [1:0] = 11
Toggle Output select
Note PTnIO [1:0] = 10
Active High Output select
Output Inverts
when PTnPOL is high
Output Pin
Reset to Initial value
un-defined
Compare Match Output Mode – PTnCCLR=0 (n=0, 1)
Note: 1. With PTnCCLR=0 a Comparator P match will clear the counter
2. The TM output pin is controlled only by the PTMnAF flag
3. The output pin is reset to itsinitial state by a PTnON bit rising edge
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Counter Value
PTnCCLR = 1; PTnM [1:0] = 00
CCRA = 0
Counter overflow
CCRA > 0 Counter cleared by CCRA value
0x3FF
CCRA=0
Resume
CCRA
Pause
Stop
Counter Restart
CCRP
Time
PTnON
PTnPAU
PTnPOL
No PTMnAF flag
generated on
CCRA overflow
CCRA Int. Flag
PTMnAF
CCRP Int. Flag
PTMnPF
PTM O/P
Pin
PTMPF not
generated
Output pin set to
initial Level Low
if PTnOC=0
Output does
not change
Output Toggle with
PTMnAF flag
Here PTnIO [1:0] = 11
Toggle Output select
Output not affected by
PTMnAF flag. Remains High
until reset by PTnON bit
Note PTnIO [1:0] = 10
Active High Output select
Output Inverts
when PTnPOL is high
Output Pin
Reset to Initial value
Output controlled by
other pin-shared function
Compare Match Output Mode – PTnCCLR=1 (n=0, 1)
Note: 1. With PTnCCLR=1 a Comparator A match will clear the counter
2. The TM output pin is controlled only by the PTMnAF flag
3. The output pin is reset to its initial state by a PTnON bit rising edge
4. A PTMnPF flag is not generated when PTnCCLR=1
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Timer/Counter Mode
To select this mode, bits PTnM1 and PTnM0 in the PTMnC1 register should be set to 11
respectively. The Timer/Counter Mode operates in an identical way to the Compare Match Output
Mode generating the same interrupt flags. The exception is that in the Timer/Counter Mode the
TM output pin is not used. Therefore the above description and Timing Diagrams for the Compare
Match Output Mode can be used to understand its function. As the TM output pin is not used in this
mode, the pin can be used as a normal I/O pin or other pin-shared function.
PWM Output Mode
To select this mode, bits PTnM1 and PTnM0 in the PTMnC1 register should be set to 10 respectively
and also the PTnIO1 and PTnIO0 bits should be set to 10 respectively. The PWM function within
the TM is useful for applications which require functions such as motor control, heating control,
illumination control etc. By providing a signal of fixed frequency but of varying duty cycle on the
TM output pin, a square wave AC waveform can be generated with varying equivalent DC RMS
values.
As both the period and duty cycle of the PWM waveform can be controlled, the choice of generated
waveform is extremely flexible. In the PWM mode, the PTnCCLR bit has no effect as the PWM
period. Both of the CCRA and CCRP registers are used to generate the PWM waveform, one register
is used to clear the internal counter and thus control the PWM waveform frequency, while the other
one is used to control the duty cycle. The PWM waveform frequency and duty cycle can therefore
be controlled by the values in the CCRA and CCRP registers.
An interrupt flag, one for each of the CCRA and CCRP, will be generated when a compare match
occurs from either Comparator A or Comparator P. The PTnOC bit in the PTMnC1 register is used to
select the required polarity of the PWM waveform while the two PTnIO1 and PTnIO0 bits are used
to enable the PWM output or to force the TM output pin to a fixed high or low level. The PTnPOL
bit is used to reverse the polarity of the PWM output waveform.
• 10-bit PWM Mode, Edge-aligned Mode
CCRP
0
Period
1024
1~1023
Duty
1~1023
CCRA
If fSYS = 16MHz, TM clock source select fSYS/4, CCRP = 512 and CCRA = 128,
The PTM PWM output frequency = (fSYS/4) /512 = fSYS/2048 = 7.8125kHz, duty = 128/512 = 25%.
If the Duty value defined by the CCRA register is equal to or greater than the Period value, then the
PWM output duty is 100%.
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Counter Value
PTnM [1:0] = 10 ; PTnIO [1:0]=10
Counter cleared
by CCRP
Counter Reset when
PTnON returns high
CCRP
Pause Resume
CCRA
Counter Stop if
PTnON bit low
Time
PTnON
PTnPAU
PTnPOL
CCRA Int. Flag
PTMnAF
CCRP Int. Flag
PTMnPF
PTM O/P Pin
(PTnOC=1)
PTM O/P Pin
(PTnOC=0)
PWM Duty Cycle
set by CCRA
PWM Period
set by CCRP
PWM resumes
operation
Output controlled by
Output Inverts
other pin-shared function
When PTnPOL = 1
PWM mode (n=0, 1)
Note: 1. A counter clear sets the PWM Period
2. The internal PWM function continues running even when PTnIO [1:0] = 00 or 01
3. The PTnCCLR bit has no influence on PWM operation
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Single Pulse Mode
To select this mode, bits PTnM1 and PTnM0 in the PTMnC1 register should be set to 10
respectively and also the PTnIO1 and PTnIO0 bits should be set to 11 respectively. The Single Pulse
Output Mode, as the name suggests, will generate a single shot pulse on the TM output pin.
The trigger for the pulse output leading edge is a low to high transition of the PTnON bit, which
can be implemented using the application program. However in the Single Pulse Mode, the PTnON
bit can also be made to automatically change from low to high using the external PTCKn pin,
which will in turn initiate the Single Pulse output. When the PTnON bit transitions to a high level,
the counter will start running and the pulse leading edge will be generated. The PTnON bit should
remain high when the pulse is in its active state. The generated pulse trailing edge will be generated
when the PTnON bit is cleared to zero, which can be implemented using the application program or
when a compare match occurs from Comparator A.
However a compare match from Comparator A will also automatically clear the PTnON bit and thus
generate the Single Pulse output trailing edge. In this way the CCRA value can be used to control
the pulse width. A compare match from Comparator A will also generate a TM interrupt. The counter
can only be reset back to zero when the PTnON bit changes from low to high when the counter
restarts. In the Single Pulse Mode CCRP is not used. The PTnCCLR bit is not used in this Mode.
            Single Pulse Generation (n=0, 1)
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Counter Value
PTnM [1:0] = 10 ; PTnIO [1:0] = 11
Counter stopped
by CCRA
Counter Reset when
PTnON returns high
CCRA
Pause
Counter Stops
by software
Resume
CCRP
Time
PTnON
Software
Trigger
Auto. set by
PTCKn pin
Cleared by
CCRA match
PTCKn pin
Software
Trigger
Software
Trigger
Software
Clear
Software
Trigger
PTCKn pin
Trigger
PTnPAU
PTnPOL
No CCRP Interrupts
generated
CCRP Int. Flag
PTMnPF
CCRA Int. Flag
PTMnAF
PTM O/P Pin
(PTnOC=1)
PTM O/P Pin
(PTnOC=0)
Output Inverts
when PTnPOL = 1
Pulse Width
set by CCRA
Single Pulse Mode (n=0, 1)
Note: 1. Counter stopped by CCRA
2. CCRP is not used
3. The pulse is triggered by the PTCKn pin or by setting the PTnON bit high
4. A PTCKn pin active edge will automatically set the PTnON bit hight
5. In the Single Pulse Mode, PTnIO [1:0] must be set to “11” and can not be changed.
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Capture Input Mode
To select this mode bits PTnM1 and PTnM0 in the PTMnC1 register should be set to 01 respectively.
This mode enables external signals to capture and store the present value of the internal counter
and can therefore be used for applications such as pulse width measurements. The external signal is
supplied on the PTPn or PTCKn pin, selected by the PTnCKS bit in the PTMnC1 register. The input
pin active edge can be a rising edge, a falling edge or both rising and falling edges; the active edge
transition type is selected using the PTnIO1 and PTnIO0 bits in the PTMnC1 register. The counter
is started when the PTnON bit changes from low to high which is initiated using the application
program.
When the required edge transition appears on the PTPn or PTCKn pin the present value in the
counter will be latched into the CCRA registers and a TM interrupt generated. Irrespective of what
events occur on the PTPn or PTCKn pin the counter will continue to free run until the PTnON
bit changes from high to low. When a CCRP compare match occurs the counter will reset back
to zero; in this way the CCRP value can be used to control the maximum counter value. When a
CCRP compare match occurs from Comparator P, a TM interrupt will also be generated. Counting
the number of overflow interrupt signals from the CCRP can be a useful method in measuring long
pulse widths. The PTnIO1 and PTnIO0 bits can select the active trigger edge on the PTPn or PTCKn
pin to be a rising edge, falling edge or both edge types. If the PTnIO1 and PTnIO0 bits are both set
high, then no capture operation will take place irrespective of what happens on the PTPn or PTCKn
pin, however it must be noted that the counter will continue to run.
As the PTPn pin is pin or PTCKn pin shared with other functions, care must be taken if the PTMn
is in the Input Capture Mode. This is because if the pin is setup as an output, then any transitions on
this pin may cause an input capture operation to be executed. The PTnCCLR, PTnOC and PTnPOL
bits are not used in this Mode.
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Counter Value
PTnM [1:0] = 01
Counter cleared
by CCRP
Counter Counter
Reset
Stop
CCRP
YY
Pause
Resume
XX
Time
PTnON
PTnPAU
Active
edge
Active
edge
Active edge
PTMn capture pin
PTPn or PTCKn
CCRA Int. Flag
PTMnAF
CCRP Int. Flag
PTMnPF
CCRA
Value
PTnIO [1:0]
Value
XX
00 – Rising edge
YY
01 – Falling edge
XX
10 – Both edges
YY
11 – Disable Capture
Capture Input Mode (n=0, 1)
Note: 1. PTnM [1:0] = 01 and active edge set by the PTnIO [1:0] bits
2. A TM Capture input pin active edge transfers the counter value to CCRA
3. PTnCCLR bit not used
4. No output function – PTnOC and PTnPOL bits are not used
5. CCRP determines the counter value and the counter has a maximum count value when CCRP is equal to
zero.
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Analog to Digital Converter
The need to interface to real world analog signals is a common requirement for many electronic
systems. However, to properly process these signals by a microcontroller, they must first be
converted into digital signals by A/D converters. By integrating the A/D conversion electronic
circuitry into the microcontroller, the need for external components is reduced significantly with the
corresponding follow-on benefits of lower costs and reduced component space requirements.
A/D Overview
The device contains a 8-channel analog to digital converter which can directly interface to external
analog signals, such as that from sensors or other control signals and convert these signals directly
into a 12-bit digital value.
The accompanying block diagram shows the overall internal structure of the A/D converter, together
with its associated registers.
­ ­   
€ 
… † ‡
ƒ
   
 

„ ˆ
   ‚
      
 
 A/D Converter Structure
A/D Converter Register Description
Overall operation of the A/D converter is controlled using five registers. A read only register pair
exists to store the ADC data 12-bit value. The remaining three registers are control registers which
setup the operating and control function of the A/D converter.
Register
Name
Bit
7
6
5
4
3
2
1
0
ADRL(ADRFS=0)
D3
D2
D1
D0
—
—
—
—
ADRH(ADRFS=0)
D11
D10
D9
D8
D7
D6
D5
D4
ADRL(ADRFS=1)
D7
D6
D5
D4
D3
D2
D1
D0
ADRH(ADRFS=1)
—
—
—
—
D11
D10
D9
D8
START
EOCB
ADOFF
ADRFS
—
ACS2
ACS1
ACS0
ADCR1
ACS4
V125EN
—
ADCK2
ADCK1
ADCK0
ACERL
ACE7
ACE6
ACE5
ACE2
ACE1
ACE0
ADCR0
VREFS1 VREFS0
ACE4
ACE3
A/D Converter Register List
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A/D Converter Data Registers – ADRL, ADRH
As the device contains an internal 12-bit A/D converter, it requires two data registers to store the
converted value. These are a high byte register, known as ADRH, and a low byte register, known
as ADRL. After the conversion process takes place, these registers can be directly read by the
microcontroller to obtain the digitised conversion value. As only 12 bits of the 16-bit register space
is utilised, the format in which the data is stored is controlled by the ADRFS bit in the ADCR0
register as shown in the accompanying table. D0~D11 are the A/D conversion result data bits. Any
unused bits will be read as zero.
ADRFS
0
1
ADRH
7
6
D11 D10
0
0
ADRL
5
4
3
2
1
0
7
6
5
4
3
2
1
0
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
0
0
0
0
0
0
D11 D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
A/D Data Registers
A/D Converter Control Registers – ADCR0, ADCR1, ACERL
To control the function and operation of the A/D converter, three control registers known as
ADCR0, ADCR1, ACERL are provided. These 8-bit registers define functions such as the selection
of which analog channel is connected to the internal A/D converter, the digitised data format, the
A/D clock source as well as controlling the start function and monitoring the A/D converter end of
conversion status. The ACS4 in the ADCR1 register and ACS2~ACS0 bits in the ADCR0 register
define the ADC input channel number. As the device contains only one actual analog to digital
converter hardware circuit, each of the individual 8 analog inputs must be routed to the converter. It
is the function of the ACS4, ACS2 ~ ACS0 bits to determine which analog channel input signals or
internal VBG is actually connected to the internal A/D converter.
The ACERL control register contains the ACE7~ACE0 bits which determine which pins on Port C
are used as analog inputs for the A/D converter input and which pins are not to be used as the A/D
converter input. Setting the corresponding bit high will select the A/D input function, clearing the
bit to zero will select either the I/O or other pin-shared function. When the pin is selected to be an
A/D input, its original function whether it is an I/O or other pin-shared function will be removed. In
addition, any internal pull-high resistors connected to these pins will be automatically removed if the
pin is selected to be an A/D input.
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ADCR0 Register
Bit
7
6
5
4
3
2
1
0
Name
START
EOCB
ADOFF
ADRFS
—
ACS2
ACS1
ACS0
R/W
R/W
R
R/W
R/W
—
R/W
R/W
R/W
POR
0
1
1
0
—
0
0
0
Bit 7START: Start the A/D conversion
0→1→0: start
0→1: reset the A/D converter and set EOCB to "1"
This bit is used to initiate an A/D conversion process. The bit is normally low but if set
high and then cleared low again, the A/D converter will initiate a conversion process.
When the bit is set high the A/D converter will be reset.
Bit 6EOCB: End of A/D conversion flag
0: A/D conversion ended
1: A/D conversion in progress
This read only flag is used to indicate when an A/D conversion process has completed.
When the conversion process is running the bit will be high.
Bit 5ADOFF : ADC module power on/off control bit
0: ADC module power on
1: ADC module power off
This bit controls the power to the A/D internal function. This bit should be cleared
to zero to enable the A/D converter. If the bit is set high then the A/D converter will
be switched off reducing the device power consumption. As the A/D converter will
consume a limited amount of power, even when not executing a conversion, this may
be an important consideration in power sensitive battery powered applications.
Note: 1. it is recommended to set ADOFF=1 before entering IDLE/SLEEP Mode for
saving power.
2. ADOFF=1 will power down the ADC module.
Bit 4ADRFS: ADC Data Format Control
0: ADC Data MSB is ADRH bit 7, LSB is ADRL bit 4
1: ADC Data MSB is ADRH bit 3, LSB is ADRL bit 0
This bit controls the format of the 12-bit converted A/D value in the two A/D data
registers. Details are provided in the A/D data register section.
Rev. 1.00
Bit 3
Unimplemented, read as “0”
Bit 2 ~ 0
ACS2 ~ ACS0: Select A/D channel (when ACS4 is “0”)
000: AN0
001: AN1
010: AN2
011: AN3
100: AN4
101: AN5
110: AN6
111: AN7
These are the A/D channel select control bits. As there is only one internal hardware A/D
converter each of the eight A/D inputs must be routed to the internal converter using
these bits. If bit ACS4 in the ADCR1 register is set high then the internal VBG will be
routed to the A/D Converter.
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ADCR1 Register
Bit
7
6
5
4
3
2
1
0
Name
ACS4
V125EN
—
—
VREFS
ADCK2
ADCK1
ADCK0
R/W
R/W
R/W
—
—
R/W
R/W
R/W
R/W
POR
0
0
—
—
0
0
0
0
Bit 7ACS4: Selecte Internal VBG as ADC input Control
0: Disable
1: Enable
This bit enables VBG to be connected to the A/D converter. The V125EN bit must
first have been set to enable the bandgap circuit VBG voltage to be used by the A/D
converter. When the ACS4 bit is set high, the bandgap voltage will be routed to the A/
D converter and the other A/D input channels disconnected.
Bit 6V125EN: Internal VBG Control
0: Disable
1: Enable
This bit controls the internal Bandgap circuit on/off function to the A/D converter.
When the bit is set high the bandgap voltage VBG can be used by the A/D converter.
If VBG is not used by the A/D converter and the LVR function is disabled then the
bandgap reference circuit will be automatically switched off to conserve power. When
VBG is switched on for use by the A/D converter, a time tBG should be allowed for the
bandgap circuit to stabilise before implementing an A/D conversion.
Bit 5~4
Unimplemented, read as "0"
Bit 3VREFS: Selecte ADC reference voltage
0: Internal ADC power AVDD
1: VREF pin
This bit is used to select the reference voltage for the A/D converter. If the bit is 1 then
the A/D converter reference voltage is supplied on the external pin VREF. If the pin is
0 then the internal reference is used which is taken from the power supply pin AVDD.
When the A/D converter reference voltage is supplied on the external pin VREF which
is pin-shared with other functions, all of the other pin-shared functions on this pin are
disabled.
Bit 2 ~ 0
Rev. 1.00
ADCK2 ~ ADCK0: Select ADC clock source
000: fSYS
001: fSYS/2
010: fSYS/4
011: fSYS/8
100: fSYS/16
101: fSYS/32
110: fSYS/64
111: Undefined
These three bits are used to select the clock source for the A/D converter.
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ACERL Register
Bit
7
6
5
4
3
2
1
0
Name
ACE7
ACE6
ACE5
ACE4
ACE3
ACE2
ACE1
ACE0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
1
1
1
1
1
1
1
1
Bit 7ACE7: Define PB1 is A/D input or not
0: Not A/D input
1: A/D input, AN7
Bit 6ACE6: Define PC6 is A/D input or not
0: Not A/D input
1: A/D input, AN6
Bit 5ACE5: Define PC5 is A/D input or not
0: Not A/D input
1: A/D input, AN5
Bit 4ACE4: Define PC4 is A/D input or not
0: Not A/D input
1: A/D input, AN4
Bit 3ACE3: Define PC3 is A/D input or not
0: Not A/D input
1: A/D input, AN3
Bit 2ACE2: Define PC0 is A/D input or not
0: Not A/D input
1: A/D input, AN2
Bit 1ACE1: Define PB7 is A/D input or not
0: Not A/D input
1: A/D input, AN1
Bit 0ACE0: Define PB6 is A/D input or not
0: Not A/D input
1: A/D input, AN0
A/D Operation
The START bit in the ADCR0 register is used to start and reset the A/D converter. When the
microcontroller sets this bit from low to high and then low again, an analog to digital conversion
cycle will be initiated. When the START bit is brought from low to high but not low again, the
EOCB bit in the ADCR0 register will be set high and the analog to digital converter will be reset.
It is the START bit that is used to control the overall start operation of the internal analog to digital
converter.
The EOCB bit in the ADCR0 register is used to indicate when the analog to digital conversion
process is complete. This bit will be automatically set to “0” by the microcontroller after a
conversion cycle has ended. In addition, the corresponding A/D interrupt request flag will be set
in the interrupt control register, and if the interrupts are enabled, an appropriate internal interrupt
signal will be generated. This A/D internal interrupt signal will direct the program flow to the
associated A/D internal interrupt address for processing. If the A/D internal interrupt is disabled,
the microcontroller can be used to poll the EOCB bit in the ADCR0 register to check whether it has
been cleared as an alternative method of detecting the end of an A/D conversion cycle.
The clock source for the A/D converter, which originates from the system clock fSYS, can be chosen
to be either fSYS or a subdivided version of fSYS. The division ratio value is determined by the
ADCK2~ADCK0 bits in the ADCR1 register.
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Although the A/D clock source is determined by the system clock fSYS, and by bits ADCK2~ADCK0,
there are some limitations on the A/D clock source speed range that can be selected. As the
recommended range of permissible A/D clock period, tAD, is from 0.5μs to 10μs, care must be taken
for system clock frequencies. For example, if the system clock operates at a frequency of 4MHz, the
ADCK2~ADCK0 bits should not be set to 000B or 110B. Doing so will give A/D clock periods that
are less than the minimum A/D clock period or greater than the maximum A/D clock period which
may result in inaccurate A/D conversion values.
Refer to the following table for examples, where values marked with an asterisk * show where,
depending upon the device, special care must be taken, as the values may be less than the specified
minimum A/D Clock Period.
A/D Clock Period (tAD)
fSYS
1MHz
ADCK2,
ADCK1,
ADCK0
=000
(fSYS)
ADCK2,
ADCK1,
ADCK0
=001
(fSYS/2)
ADCK2,
ADCK1,
ADCK0
=010
(fSYS/4)
ADCK2,
ADCK1,
ADCK0
=011
(fSYS/8)
ADCK2,
ADCK1,
ADCK0
=100
(fSYS/16)
ADCK2,
ADCK1,
ADCK0
=101
(fSYS/32)
ADCK2,
ADCK1,
ADCK0
=110
(fSYS/64)
ADCK2,
ADCK1,
ADCK0
=111
1μs
2μs
4μs
8μs
16μs*
32μs*
64μs*
Undefined
2MHz
500ns
1μs
2μs
4μs
8μs
16μs*
32μs*
Undefined
4MHz
250ns*
500ns
1μs
2μs
4μs
8μs
16μs*
Undefined
Undefined
8MHz
125ns*
250ns*
500ns
1μs
2μs
4μs
8μs
12MHz
83ns*
167ns*
333ns*
667ns
1.33μs
2.67μs
5.33μs
Undefined
16MHz
62ns*
125ns*
250ns*
500ns
1μs
2μs
4μs
Undefined
A/D Clock Period Examples
Controlling the power on/off function of the A/D converter circuitry is implemented using the
ADOFF bit in the ADCR0 register. This bit must be zero to power on the A/D converter. When the
ADOFF bit is cleared to zero to power on the A/D converter internal circuitry a certain delay, as
indicated in the timing diagram, must be allowed before an A/D conversion is initiated. Even if no
pins are selected for use as A/D inputs by clearing the ACE7~ACE0 bits in the ACERL registers, if
the ADOFF bit is zero then some power will still be consumed. In power conscious applications it
is therefore recommended that the ADOFF is set high to reduce power consumption when the A/D
converter function is not being used.
The reference voltage supply to the A/D Converter can be supplied from either the positive power
supply pin, AVDD, or from an external reference source supplied on pin VREF. The desired
selection is made using the VREFS bit. As the pin is pin-shared with other function, when the VREF
pin function is selected, then the other pin functions will be disabled automatically.
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A/D Input Pins
All of the A/D analog input pins are pin-shared with the I/O pins on Port C as well as other
functions. The ACE7~ACE0 bits in the ACERL registers, determine whether the input pins are setup
as A/D converter analog inputs or whether they have other functions. If the ACE7~ACE0 bits for its
corresponding pin is set high then the pin will be setup to be an A/D converter input and the original
pin functions disabled. In this way, pins can be changed under program control to change their
function between A/D inputs and other functions. All pull-high resistors, which are setup through
register programming, will be automatically disconnected if the pins are setup as A/D inputs. Note
that it is not necessary to first setup the A/D pin as an input in the PCC port control register to enable
the A/D input as when the ACE7~ACE0 bits enable an A/D input, the status of the port control
register will be overridden.
The A/D converter has its own reference voltage pins, VREF, however the reference voltage can
also be supplied from the power supply pin, a choice which is made through the VREFS bit in the
ADCR1 register.
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   A/D Input Structure
Summary of A/D Conversion Steps
The following summarises the individual steps that should be executed in order to implement an A/D
conversion process.
• Step 1
Select the required A/D conversion clock by correctly programming bits ADCK2~ADCK0 in the
ADCR1 register.
• Step 2
Enable the A/D by clearing the ADOFF bit in the ADCR0 register to zero.
• Step 3
Select which channel is to be connected to the internal A/D converter by correctly programming
the ACS4, ACS2~ACS0 bits which are also contained in the ADCR1 and ADCR0 register.
• Step 4
Select which pins are to be used as A/D inputs and configure them by correctly programming the
ACE7~ACE0 bits in the ACERL register.
• Step 5
If the interrupts are to be used, the interrupt control registers must be correctly configured to
ensure the A/D converter interrupt function is active. The master interrupt control bit, EMI, and
the A/D converter interrupt bit, ADE, must both be set high to do this.
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• Step 6
The analog to digital conversion process can now be initialised by setting the START bit in
the ADCR0 register from low to high and then low again. Note that this bit should have been
originally cleared to zero.
• Step 7
To check when the analog to digital conversion process is complete, the EOCB bit in the ADCR0
register can be polled. The conversion process is complete when this bit goes low. When this
occurs the A/D data registers ADRL and ADRH can be read to obtain the conversion value. As an
alternative method, if the interrupts are enabled and the stack is not full, the program can wait for
an A/D interrupt to occur.
Note: When checking for the end of the conversion process, if the method of polling the EOCB
bit in the ADCR0 register is used, the interrupt enable step above can be omitted.
The accompanying diagram shows graphically the various stages involved in an analog to digital
conversion process and its associated timing. After an A/D conversion process has been initiated
by the application program, the microcontroller internal hardware will begin to carry out the
conversion, during which time the program can continue with other functions. The time taken for the
A/D conversion is 16tAD where tAD is equal to the A/D clock period.
ADOFF
tON2ST
ADC module ON
off
on
off
A/D sampling time
A/D sampling time
tADCS
START
on
tADCS
EOCB
ACS[4, 2:0]
0011B
Power-on
Reset
0010B
0000B
Reset A/D
conversion
Reset A/D
conversion
Start of A/D
conversion
End of A/D
conversion
Start of A/D
conversion
tADC
A/D conversion time
0001B
Start of A/D conversion
Reset A/D
conversion
End of A/D
conversion
tADC
A/D conversion time
Note: A/D clock must be fSYS, fSYS/2, fSYS/4, fSYS/8, fSYS/16, fSYS/32, fSYS/64,
tADCS=4tAD
tADC=tADCS+n*tAD; n=bit count of ADC resolution
tON2ST: at least one instruction cycle (fSYS = 12MHz)
A/D Conversion Timing
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Programming Considerations
During microcontroller operations where the A/D converter is not being used, the A/D internal
circuitry can be switched off to reduce power consumption, by setting bit ADOFF high in the
ADCR0 register. When this happens, the internal A/D converter circuits will not consume power
irrespective of what analog voltage is applied to their input lines. If the A/D converter input lines are
used as normal I/Os, then care must be taken as if the input voltage is not at a valid logic level, then
this may lead to some increase in power consumption.
A/D Transfer Function
As the device contains a 12-bit A/D converter, its full-scale converted digitised value is equal to
FFFH. Since the full-scale analog input value is equal to the AVDD or VREF voltage, this gives a single
bit analog input value of AVDD or VREF divided by 4096.
1 LSB= (AVDD or VREF) /4096
The A/D Converter input voltage value can be calculated using the following equation:
A/D input voltage = A/D output digital value × (AVDD or VREF) /4096
The diagram shows the ideal transfer function between the analog input value and the digitised
output value for the A/D converter. Except for the digitised zero value, the subsequent digitised
values will change at a point 0.5 LSB below where they would change without the offset, and the
last full scale digitised value will change at a point 1.5 LSB below the AVDD or VREF level.
    
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A/D Programming Examples
The following two programming examples illustrate how to setup and implement an A/D conversion.
In the first example, the method of polling the EOCB bit in the ADCR0 register is used to detect
when the conversion cycle is complete, whereas in the second example, the A/D interrupt is used to
determine when the conversion is complete.
Example: using an EOCB polling method to detect the end of conversion
clr ADE ;
mova,03H
mov ADCR1,a;
clr ADOFF
mova,0Fh ;
mov ACERL,a
mova,00h
mov ADCR0,a ;
:
start_conversion:
clr START ;
set START ;
clr START ;
polling_EOC:
sz EOCB ;
jmp polling_EOC ;
mov a,ADRL ;
mov ADRL_buffer,a ;
mov a,ADRH ;
mov ADRH_buffer,a ;
:
:
jmp start_conversion ;
Rev. 1.00
disable ADC interrupt
select fSYS/8 as A/D clock and switch off VBG
setup ACERL to configure pins AN0~AN3
enable and connect AN0 channel to A/D converter
high pulse on start bit to initiate conversion
reset A/D
start A/D
poll the ADCR0 register EOCB bit to detect end of A/D conversion
continue polling
read low byte conversion result value
save result to user defined register
read high byte conversion result value
save result to user defined register
start next a/d conversion
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Example: using the interrupt method to detect the end of conversion
clr ADE ;
mova,03H
mov ADCR1,a ;
Clr ADOFF
mova,0Fh ;
mov ACERL,a
mova,00h
mov ADCR0,a ;
Start_conversion:
clr START ;
set START ;
clr START ;
clrADF ;
set ADE ;
set EMI ;
:
:
;
ADC_ISR:
mov acc_stack,a ;
mov a,STATUS
mov status_stack,a ;
:
:
mov a,ADRL ;
mov adrl_buffer,a ;
mov a,ADRH ;
mov adrh_buffer,a ;
:
:
EXIT_INT_ISR:
mov a,status_stack
mov STATUS,a ;
mov a,acc_stack ;
reti
Rev. 1.00
disable ADC interrupt
select fSYS/8 as A/D clock and switch off VBG
setup ACERL to configure pins AN0~AN3
enable and connect AN0 channel to A/D converter
high pulse on START bit to initiate conversion
reset A/D
start A/D
clear ADC interrupt request flag
enable ADC interrupt
enable global interrupt
ADC interrupt service routine
save ACC to user defined memory
save STATUS to user defined memory
read
save
read
save
low byte conversion result value
result to user defined register
high byte conversion result value
result to user defined register
restore STATUS from user defined memory
restore ACC from user defined memory
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Serial Interface Module – SIM
The device contains a Serial Interface Module, which includes both the four-line SPI interface or
two-line I2C interface types, to allow an easy method of communication with external peripheral
hardware. Having relatively simple communication protocols, these serial interface types allow
the microcontroller to interface to external SPI or I2C based hardware such as sensors, Flash or
EEPROM memory, etc. The SIM interface pins are pin-shared with other I/O pins and therefore the
SIM interface functional pins must first be selected using the corresponding pin-shared function
selection bits. As both interface types share the same pins and registers, the choice of whether the SPI
or I2C type is used is made using the SIM operating mode control bits, named SIM2~SIM0, in the
SIMC0 register. These pull-high resistors of the SIM pin-shared I/O pins are selected using pull-high
control registers when the SIM function is enabled and the corresponding pins are used as SIM input
pins.
SPI Interface
The SPI interface is often used to communicate with external peripheral devices such as sensors,
Flash Memory or EEPROM memory devices etc. Originally developed by Motorola, the four line
SPI interface is a synchronous serial data interface that has a relatively simple communication
protocol simplifying the programming requirements when communicating with external hardware
devices.
The communication is full duplex and operates as a slave/master type, where the device can be either
master or slave. Although the SPI interface specification can control multiple slave devices from a
single master, but the device provides only one SCS pin. If the master needs to control multiple slave
devices from a single master, the master can use I/O pin to select the slave devices.
SPI Interface Operation
The SPI interface is a full duplex synchronous serial data link. It is a four line interface with pin
names SDI, SDO, SCK and SCS. Pins SDI and SDO are the Serial Data Input and Serial Data
Output lines, SCK is the Serial Clock line and SCS is the Slave Select line. As the SPI interface pins
are pin-shared with normal I/O pins and with the I2C function pins, the SPI interface pins must first
be selected by configuring the pin-shared function selection bits and setting the correct bits in the
SIMC0 and SIMC2 registers. After the desired SPI configuration has been set it can also be disabled
or enabled using the SIMEN bit in the SIMC0 register. Communication between devices connected
to the SPI interface is carried out in a slave/master mode with all data transfer initiations being
implemented by the master. The Master also controls the clock signal. As the device only contains
a single SCS pin only one slave device can be utilized. The SCS pin is controlled by software, set
CSEN bit to “1” to enable SCS pin function, set CSEN bit to “0” the SCS pin will be floating state.
The SPI function in this device offers the following features:
• Full duplex synchronous data transfer
• Both Master and Slave modes
• LSB first or MSB first data transmission modes
• Transmission complete flag
• Rising or falling active clock edge
The status of the SPI interface pins is determined by a number of factors such as whether the device
is in the master or slave mode and upon the condition of certain control bits such as CSEN and
SIMEN.
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SPI Master/Slave Connection
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SPI Register
There are three internal registers which control the overall operation of the SPI interface. These are
the SIMD data register and two control registers SIMC0 and SIMC2.
Bit
Register
Name
7
6
5
4
SIMC0
SIM2
SIM1
SIM0
—
SIMD
D7
D6
D5
D4
D3
D2
D1
D0
SIMC2
D7
D6
CKPOLB
CKEG
MLS
CSEN
WCOL
TRF
3
2
1
SIMDBNC1 SIMDBNC0 SIMEN
0
SPIICF
SIM Registers List
The SIMD register is used to store the data being transmitted and received. The same register is used
by both the SPI and I2C functions. Before the devices write data to the SPI bus, the actual data to
be transmitted must be placed in the SIMD register. After the data is received from the SPI bus, the
device can read it from the SIMD register. Any transmission or reception of data from the SPI bus
must be made via the SIMD register.
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SIMD Register
Bit
7
6
5
4
3
2
1
0
Name
D7
D6
D5
D4
D3
D2
D1
D0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
×
×
×
×
×
×
×
×
"×": unknown
There are also two control registers for the SPI interface, SIMC0 and SIMC2. Note that the SIMC2
register also has the name SIMA which is used by the I2C function. The SIMC1 register is not used
by the SPI function, only by the I2C function. Register SIMC0 is used to control the enable/disable
function and to set the data transmission clock frequency. Although not connected with the SPI
function, the SIMC0 register is also used to control the Peripheral Clock Prescaler. Register SIMC2
is used for other control functions such as LSB/MSB selection, write collision flag etc.
SIMC0 Register
Bit
7
6
5
4
3
2
1
Name
SIM2
SIM1
SIM0
—
R/W
R/W
R/W
R/W
—
R/W
R/W
R/W
R/W
POR
1
1
1
—
0
0
0
0
SIMDBNC1 SIMDBNC0 SIMEN
0
SPIICF
Bit 7 ~ 5SIM2~SIM0: SIM Operating Mode Control
000: SPI master mode; SPI clock is fSYS/4
001: SPI master mode; SPI clock is fSYS/16
010: SPI master mode; SPI clock is fSYS/64
011: SPI master mode; SPI clock is fSUB
100: SPI master mode; SPI clock is CTM CCRP match frequency/2
101: SPI slave mode
110: I2C slave mode
111: Unused mode
These bits setup the overall operating mode of the SIM function. As well as selecting
if the I2C or SPI function, they are used to control the SPI Master/Slave selection and
the SPI Master clock frequency. The SPI clock is a function of the system clock but
can also be chosen to be sourced from the CTM. If the SPI Slave Mode is selected
then the clock will be supplied by an external Master device.
Bit 4
Unimplemented, read as “0”
Bit 3 ~ 2SIMDBNC1~SIMDBNC0: I2C Debounce Time Selection 00: No debounce
01: 2 system clocks debounce
1x: 4 system clocks debounce
Bit 1SIMEN: SIM Control
0: Disable
1: Enable
The bit is the overall on/off control for the SIM interface. When the SIMEN bit is
cleared to zero to disable the SIM interface, the SDI, SDO, SCK and SCS, or SDA and
SCL lines will lose their SPI or I2C function and the SIM operating current will be
reduced to a minimum value. When the bit is high the SIM interface is enabled. If the
SIM is configured to operate as an SPI interf ace via the SIM2~SIM0 bits, the contents
of the SPI control registers will remain at the previous settings when the SIMEN bit
changes from low to high and should therefore be first initialised by the application
program. If the SIM is configured to operate as an I2C interface via the SIM2~SIM0
bits and the SIMEN bit changes from low to high, the contents of the I2C control bits
such as HTX and TXAK will remain at the previous settings and should therefore be
first initialised by the application program while the relevant I2C flags such as HCF,
HAAS, HBB, SRW and RXAK will be set to their default states.
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Bit 0SPIICF: SPI Incompleted Flag
0: SPI incompleted is not occurred
1: SPI incompleted is occurred
The SPIICF bit is determined by SCS pin. When SCS pin is set to “1”, it will clear the
SPI counter. Meanwhile, the interrupt is occurred, if slave device didn’t complete data
received, then the incompleted flag, SPIICF, is set to “1”.
SIMC2 Register
Bit
7
6
5
4
3
2
1
0
Name
D7
D6
CKPOLB
CKEG
MLS
CSEN
WCOL
TRF
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7 ~ 6
Undefined bits
These bits can be read or written by user software program.
Bit 5CKPOLB: Determines the base condition of the clock line
0: The SCK line will be high when the clock is inactive
1: The SCK line will be low when the clock is inactive
The CKPOLB bit determines the base condition of the clock line, if the bit is high,
then the SCK line will be low when the clock is inactive. When the CKPOLB bit is
low, then the SCK line will be high when the clock is inactive.
Bit 4CKEG: Determines SPI SCK active clock edge type
CKPOLB=0
0: SCK is high base level and data capture at SCK rising edge
1: SCK is high base level and data capture at SCK falling edge
CKPOLB=1
0: SCK is low base level and data capture at SCK falling edge
1: SCK is low base level and data capture at SCK rising edge
The CKEG and CKPOLB bits are used to setup the way that the clock signal outputs
and inputs data on the SPI bus. These two bits must be configured before data transfer
is executed otherwise an erroneous clock edge may be generated. The CKPOLB bit
determines the base condition of the clock line, if the bit is high, then the SCK line
will be low when the clock is inactive. When the CKPOLB bit is low, then the SCK
line will be high when the clock is inactive. The CKEG bit determines active clock
edge type which depends upon the condition of CKPOLB bit.
Bit 3MLS: SPI Data shift order
0: LSB
1: MSB
This is the data shift select bit and is used to select how the data is transferred, either
MSB or LSB first. Setting the bit high will select MSB first and low for LSB first.
Bit 2CSEN: SPI SCS pin Control
0: Disable
1: Enable
The CSEN bit is used as an enable/disable for the SCS pin. If this bit is low, then the
SCS pin will be disabled and placed into I/O pin or the other functions. If the bit is
high the SCS pin will be enabled and used as a select pin.
Bit 1WCOL: SPI Write Collision flag
0: No collision
1: Collision
The WCOL flag is used to detect if a data collision has occurred. If this bit is high it
means that data has been attempted to be written to the SIMD register during a data
transfer operation. This writing operation will be ignored if data is being transferred.
The bit can be cleared by the application program.
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Bit 0TRF: SPI Transmit/Receive Complete flag
0: Data is being transferred
1: SPI data transmission is completed
The TRF bit is the Transmit/Receive Complete flag and is set “1” automatically when
an SPI data transmission is completed, but must set to “0” by the application program.
It can be used to generate an interrupt.
SPI Communication
After the SPI interface is enabled by setting the SIMEN bit high, then in the Master Mode, when
data is written to the SIMD register, transmission/reception will begin simultaneously. When the
data transfer is complete, the TRF flag will be set automatically, but must be cleared using the
application program. In the Slave Mode, when the clock signal from the master has been received,
any data in the SIMD register will be transmitted and any data on the SDI pin will be shifted into
the SIMD register. The master should output a SCS signal to enable the slave device before a clock
signal is provided. The slave data to be transferred should be well prepared at the appropriate
moment relative to the SCS signal depending upon the configurations of the CKPOLB bit and CKEG
bit. The accompanying timing diagram shows the relationship between the slave data and SCS signal
for various configurations of the CKPOLB and CKEG bits. The SPI will continue to function even
in the IDLE Mode.
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I2C Interface
The I 2C interface is used to communicate with external peripheral devices such as sensors,
EEPROM memory etc. Originally developed by Philips, it is a two line low speed serial interface
for synchronous serial data transfer. The advantage of only two lines for communication, relatively
simple communication protocol and the ability to accommodate multiple devices on the same bus
has made it an extremely popular interface type for many applications.
I2C Master Slave Bus Connection
I2C Interface Operation
The I2C serial interface is a two line interface, a serial data line, SDA, and serial clock line, SCL. As
many devices may be connected together on the same bus, their outputs are both open drain types.
For this reason it is necessary that external pull-high resistors are connected to these outputs. Note
that no chip select line exists, as each device on the I2C bus is identified by a unique address which
will be transmitted and received on the I2C bus.
When two devices communicate with each other on the bidirectional I2C bus, one is known as the
master device and one as the slave device. Both master and slave can transmit and receive data,
however, it is the master device that has overall control of the bus. For these devices, which only
operates in slave mode, there are two methods of transferring data on the I2C bus, the slave transmit
mode and the slave receive mode. The pull-up control function pin-shared with SCL/SDA pin is still
applicable even if I2C device is activated and the related internal pull-up register could be controlled
by its corresponding pull-up control register.
S T A R T s ig n a l
fro m M a s te r
S e n d s la v e a d d r e s s
a n d R /W b it fr o m M a s te r
A c k n o w le d g e
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S e n d d a ta b y te
fro m M a s te r
A c k n o w le d g e
fr o m s la v e
S T O P s ig n a l
fro m M a s te r
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I2C Register
There are four control registers associated with the I2C bus, SIMC0, SIMC1, SIMA and SIMTOC
and one data register, SIMD. The SIMD register, which is shown in the above SPI section, is used to
store the data being transmitted and received on the I2C bus. Before the microcontroller writes data
to the I2C bus, the actual data to be transmitted must be placed in the SIMD register. After the data is
received from the I2C bus, the microcontroller can read it from the SIMD register. Any transmission
or reception of data from the I2C bus must be made via the SIMD register.
Note that the SIMA register also has the name SIMC2 which is used by the SPI function. Bit SIMEN
and bits SIM2~SIM0 in register SIMC0 are used by the I2C interface. The SIMTOC register is used
for I2C time-out control function.
Bit
Register
Name
7
6
5
4
SIMC0
SIM2
SIM1
SIM0
—
SIMC1
HCF
HAAS
HBB
HTX
TXAK
SIMD
D7
D6
D5
D4
D3
SIMA
IICA6
IICA5
IICA4
IICA3
IICA2
SIMTOC
3
2
1
0
SIMEN
SPIICF
SRW
RCIN
RXAK
D2
D1
D0
IICA1
IICA0
D0
SIMDEB1 SIMDEB0
SIMTOEN SIMTOF SIMTOS5 SIMTOS4 SIMTOS3 SIMTOS2 SIMTOS1 SIMTOS0
I2C Register List
SIMC0 Register
Bit
7
6
5
4
Name
SIM2
SIM1
SIM0
—
3
2
1
R/W
R/W
R/W
R/W
—
R/W
R/W
R/W
R/W
POR
1
1
1
—
0
0
0
0
SIMDBNC1 SIMDBNC0 SIMEN
0
SPIICF
Bit 7 ~ 5SIM2~SIM0: SIM Operating Mode Control
000: SPI master mode; SPI clock is fSYS/4
001: SPI master mode; SPI clock is fSYS/16
010: SPI master mode; SPI clock is fSYS/64
011: SPI master mode; SPI clock is fSUB
100: SPI master mode; SPI clock is CTM CCRP match frequency/2
101: SPI slave mode
110: I2C slave mode
111: Unused mode
These bits setup the overall operating mode of the SIM function. As well as selecting
if the I2C or SPI function, they are used to control the SPI Master/Slave selection and
the SPI Master clock frequency. The SPI clock is a function of the system clock but
can also be chosen to be sourced from the CTM. If the SPI Slave Mode is selected
then the clock will be supplied by an external Master device.
Bit 4
Unimplemented, read as “0”
Bit 3 ~ 2SIMDBNC1~SIMDBNC0: I2C Debounce Time Selection 00: No debounce
01: 2 system clocks debounce
1x: 4 system clocks debounce
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Bit 1SIMEN: SIM Control
0: Disable
1: Enable
The bit is the overall on/off control for the SIM interface. When the SIMEN bit is
cleared to zero to disable the SIM interface, the SDI, SDO, SCK and SCS, or SDA and
SCL lines will lose their SPI or I2C function and the SIM operating current will be
reduced to a minimum value. When the bit is high the SIM interface is enabled. If the
SIM is configured to operate as an SPI interface via the SIM2~SIM0 bits, the contents
of the SPI control registers will remain at the previous settings when the SIMEN bit
changes from low to high and should therefore be first initialised by the application
program. If the SIM is configured to operate as an I2C interface via the SIM2~SIM0
bits and the SIMEN bit changes from low to high, the contents of the I2C control bits
such as HTX and TXAK will remain at the previous settings and should therefore be
first initialised by the application program while the relevant I2C flags such as HCF,
HAAS, HBB, SRW and RXAK will be set to their default states.
Bit 0SPIICF: SPI Incompleted Flag
0: SPI incompleted is not occurred
1: SPI incompleted is occurred
The SPIICF bit is determined by SCS pin. When SCS pin is set to “1”, it will clear the
SPI counter. Meanwhile, the interrupt is occurred, if slave device didn’t complete data
received, then the incompleted flag, SPIICF, is set to”1”.
SIMC1 Register
Bit
7
6
5
4
3
2
1
0
Name
HCF
HAAS
HBB
HTX
TXAK
SRW
IAMWU
RXAK
R/W
R
R
R
R/W
R/W
R
R/W
R
POR
1
0
0
0
0
0
0
1
Bit 7HCF: I C Bus data transfer completion flag
0: Data is being transferred
1: Completion of an 8-bit data transfer
The HCF flag is the data transfer flag. This flag will be zero when data is being
transferred. Upon completion of an 8-bit data transfer the flag will go high and an
interrupt will be generated.
2
Bit 6HAAS: I2C Bus address match flag
0: Not address match
1: Address match
The HAAS flag is the address match flag. This flag is used to determine if the slave
device address is the same as the master transmit address. If the addresses match then
this bit will be high, if there is no match then the flag will be low.
Bit 5HBB: I2C Bus busy flag
0: I2C Bus is not busy
1: I2C Bus is busy
The HBB flag is the I2C busy flag. This flag will be “1” when the I2C bus is busy
which will occur when a START signal is detected. The flag will be set to “0” when
the bus is free which will occur when a STOP signal is detected.
Bit 4HTX: Select I2C slave device is transmitter or receiver
0: Slave device is the receiver
1: Slave device is the transmitter
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Bit 3TXAK: I2C Bus transmit acknowledge flag
0: Slave send acknowledge flag
1: Slave do not send acknowledge flag
The TXAK bit is the transmit acknowledge flag. After the slave device receipt of 8-bits
of data, this bit will be transmitted to the bus on the 9th clock from the slave device.
The slave device must always set TXAK bit to “0” before further data is received.
Bit 2SRW: I2C Slave Read/Write flag
0: Slave device should be in receive mode
1: Slave device should be in transmit mode
The SRW flag is the I 2C Slave Read/Write flag. This flag determines whether
the master device wishes to transmit or receive data from the I2C bus. When the
transmitted address and slave address is match, that is when the HAAS flag is set high,
the slave device will check the SRW flag to determine whether it should be in transmit
mode or receive mode. If the SRW flag is high, the master is requesting to read data
from the bus, so the slave device should be in transmit mode. When the SRW flag
is zero, the master will write data to the bus, therefore the slave device should be in
receive mode to read this data.
Bit 1
IAMWU: I2C Address Match Wake-up Control
0: Disable
1: Enable – must be cleared by the application program after wake-up
This bit should be set to 1 to enable the I2C address match wake up from the SLEEP
or IDLE Mode. If the IAMWU bit has been set before entering the SLEEP or IDLE
mode to enable the I2C address match wake up, then this bit must be cleared by the
application program after wake-up to ensure correction device operation.
Bit 0RXAK: I2C Bus Receive acknowledge flag
0: Slave receive acknowledge flag
1: Slave do not receive acknowledge flag
The RXAK flag is the receiver acknowledge flag. When the RXAK flag is “0”, it
means that a acknowledge signal has been received at the 9th clock, after 8 bits of data
have been transmitted. When the slave device in the transmit mode, the slave device
checks the RXAK flag to determine if the master receiver wishes to receive the next
byte. The slave transmitter will therefore continue sending out data until the RXAK
flag is “1”. When this occurs, the slave transmitter will release the SDA line to allow
the master to send a STOP signal to release the I2C Bus.
The SIMD register is used to store the data being transmitted and received. The same
register is used by both the SPI and I2C functions. Before the device writes data to the
I2C bus, the actual data to be transmitted must be placed in the SIMD register. After
the data is received from the I2C bus, the device can read it from the SIMD register.
Any transmission or reception of data from the I2C bus must be made via the SIMD
register.
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A/D 8-Bit Flash MCU with EEPROM
SIMD Register
Bit
7
6
5
4
3
2
1
0
Name
D7
D6
D5
D4
D3
D2
D1
D0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
×
×
×
×
×
×
×
×
"×": unknown
SIMA Register
Bit
7
6
5
4
3
2
1
0
Name
A6
A5
A4
A3
A2
A1
A0
—
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
—
POR
0
0
0
0
0
0
0
—
bit 7 ~ 1
A6~ A0: I2C slave address
A6~ A0 is the I2C slave address bit 6 ~ bit 0.
The SIMA register is also used by the SPI interface but has the name SIMC2. The
SIMA register is the location where the 7-bit slave address of the slave device is
stored. Bits 7~1 of the SIMA register define the device slave address. Bit 0 is not
defined. When a master device, which is connected to the I2C bus, sends out an
address, which matches the slave address in the SIMA register, the slave device will
be selected. Note that the SIMA register is the same register address as SIMC2 which
is used by the SPI interface.
Bit 0 Undefined bit
This bit can be read or written by user software program.
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„ I C Block Diagram
2
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I2C Bus Communication
Communication on the I2C bus requires four separate steps, a START signal, a slave device address
transmission, a data transmission and finally a STOP signal. When a START signal is placed on
the I2C bus, all devices on the bus will receive this signal and be notified of the imminent arrival of
data on the bus. The first seven bits of the data will be the slave address with the first bit being the
MSB. If the address of the slave device matches that of the transmitted address, the HAAS bit in the
SIMC1 register will be set and an I2C interrupt will be generated. After entering the interrupt service
routine, the slave device must first check the condition of the HAAS bit to determine whether the
interrupt source originates from an address match or from the completion of an 8-bit data transfer.
During a data transfer, note that after the 7-bit slave address has been transmitted, the following bit,
which is the 8th bit, is the read/write bit whose value will be placed in the SRW bit. This bit will be
checked by the slave device to determine whether to go into transmit or receive mode. Before any
transfer of data to or from the I2C bus, the microcontroller must initialize the bus, the following are
steps to achieve this:
Step 1
Set the SIM2~SIM0 and SIMEN bits in the SIMC0 register to “110” and “1” to enable the I2C bus.
Step 2
Write the slave address of the device to the I2C bus address register SIMA.
Step 3
Set the SIME bit of the interrupt control register to enable the SIM interrupt.

 ­ €  ‚ ƒ „ …  €        I2C Bus Initialisation Flow Chart
Rev. 1.00
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A/D 8-Bit Flash MCU with EEPROM
I2C Bus Start Signal
The START signal can only be generated by the master device connected to the I2C bus and not by
the slave device. This START signal will be detected by all devices connected to the I2C bus. When
detected, this indicates that the I2C bus is busy and therefore the HBB bit will be set. A START
condition occurs when a high to low transition on the SDA line takes place when the SCL line
remains high.
Slave Address
The transmission of a START signal by the master will be detected by all devices on the I2C bus.
To determine which slave device the master wishes to communicate with, the address of the slave
device will be sent out immediately following the START signal. All slave devices, after receiving
this 7-bit address data, will compare it with their own 7-bit slave address. If the address sent out by
the master matches the internal address of the microcontroller slave device, then an internal I2C bus
interrupt signal will be generated. The next bit following the address, which is the 8th bit, defines the
read/write status and will be saved to the SRW bit of the SIMC1 register. The slave device will then
transmit an acknowledge bit, which is a low level, as the 9th bit. The slave device will also set the
status flag HAAS when the addresses match.
As an I 2C bus interrupt can come from two sources, when the program enters the interrupt
subroutine, the HAAS bit should be examined to see whether the interrupt source has come from
a matching slave address or from the completion of a data byte transfer. When a slave address is
matched, the device must be placed in either the transmit mode and then write data to the SIMD
register, or in the receive mode where it must implement a dummy read from the SIMD register to
release the SCL line.
I2C Bus Read/Write Signal
The SRW bit in the SIMC1 register defines whether the slave device wishes to read data from the
I2C bus or write data to the I2C bus. The slave device should examine this bit to determine if it is to
be a transmitter or a receiver. If the SRW flag is “1” then this indicates that the master device wishes
to read data from the I2C bus, therefore the slave device must be setup to send data to the I2C bus as
a transmitter. If the SRW flag is “0” then this indicates that the master wishes to send data to the I2C
bus, therefore the slave device must be setup to read data from the I2C bus as a receiver.
I2C Bus Slave Address Acknowledge Signal
After the master has transmitted a calling address, any slave device on the I 2C bus, whose
own internal address matches the calling address, must generate an acknowledge signal. The
acknowledge signal will inform the master that a slave device has accepted its calling address. If no
acknowledge signal is received by the master then a STOP signal must be transmitted by the master
to end the communication. When the HAAS flag is high, the addresses have matched and the slave
device must check the SRW flag to determine if it is to be a transmitter or a receiver. If the SRW flag
is high, the slave device should be setup to be a transmitter so the HTX bit in the SIMC1 register
should be set to “1”. If the SRW flag is low, then the microcontroller slave device should be setup as
a receiver and the HTX bit in the SIMC1 register should be set to “0”.
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A/D 8-Bit Flash MCU with EEPROM
I2C Bus Data and Acknowledge Signal
The transmitted data is 8-bits wide and is transmitted after the slave device has acknowledged
receipt of its slave address. The order of serial bit transmission is the MSB first and the LSB last.
After receipt of 8-bits of data, the receiver must transmit an acknowledge signal, level “0”, before
it can receive the next data byte. If the slave transmitter does not receive an acknowledge bit signal
from the master receiver, then the slave transmitter will release the SDA line to allow the master
to send a STOP signal to release the I2C Bus. The corresponding data will be stored in the SIMD
register. If setup as a transmitter, the slave device must first write the data to be transmitted into the
SIMD register. If setup as a receiver, the slave device must read the transmitted data from the SIMD
register.
When the slave receiver receives the data byte, it must generate an acknowledge bit, known as
TXAK, on the 9th clock. The slave device, which is setup as a transmitter will check the RXAK bit
in the SIMC1 register to determine if it is to send another data byte, if not then it will release the
SDA line and await the receipt of a STOP signal from the master.
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         ­ Note: *When a slave address is matched, the devices must be placed in either the transmit mode
and then write data to the SIMD register, or in the receive mode where it must implement a
dummy read from the SIMD register to release the SCL line.
I2C Communication Timing Diagram
Rev. 1.00
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A/D 8-Bit Flash MCU with EEPROM
          I2C Bus ISR Flow Chart
I2C Time-out Control
In order to reduce the I2C lockup problem due to reception of erroneous clock sources, a time-out
function is provided. If the clock source connected to the I2C bus is not received for a while, then the
I2C circuitry and registers will be reset after a certain time-out period. The time-out counter starts
to count on an I2C bus “START” & “address match” condition, and is cleared by an SCL falling
edge. Before the next SCL falling edge arrives, if the time elapsed is greater than the time-out period
specified by the SIMTOC register, then a time-out condition will occur. The time-out function will
stop when an I2C “STOP” condition occurs.
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A/D 8-Bit Flash MCU with EEPROM
S ta rt
S C L
S R W
S la v e A d d r e s s
0
1
S D A
1
1
0
1
0
A C K
1
0
I2 C t i m e - o u t
c o u n te r s ta rt
S to p
S C L
1
0
0
1
0
1
0
0
S D A
I2 C t im e - o u t c o u n t e r r e s e t
o n S C L n e g a tiv e tr a n s itio n
I2C Time-out
When an I2C time-out counter overflow occurs, the counter will stop and the SIMTOEN bit will
be cleared to zero and the SIMTOF bit will be set high to indicate that a time-out condition has
occurred. The time-out condition will also generate an interrupt which uses the I2C interrrupt vector.
When an I2C time-out occurs, the I2C internal circuitry will be reset and the registers will be reset
into the following condition:
Register
After I2C Time-out
SIMD, SIMA, SIMC0
No change
SIMC1
Reset to POR condition
I C Registers after Time-out
2
The SIMTOF flag can be cleared by the application program. There are 64 time-out period selections
which can be selected using the SIMTOS bits in the SIMTOC register. The time-out duration is
calculated by the formula: ((1~64) × (32/fSUB)). This gives a time-out period which ranges from
about 1ms to 64ms.
SIMTOC Register
Rev. 1.00
Bit
7
Name
SIMTOEN
6
5
4
3
2
1
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
SIMTOF SIMTOS5 SIMTOS4 SIMTOS3 SIMTOS2 SIMTOS1 SIMTOS0
Bit 7
SIMTOEN: I2C Time-out Control
0: Disable
1: Enable
Bit 6
SIMTOF: I2C Time-out flag
0: No time-out occurred
1: Time-out occurred
Bit 5~0
SIMTOS5~SIMTOS0: I2C Time-out Time Selection
I2C Time-out clock source is fSUB/32
I2C Time-out time is given by: (SIMTOS [5:0] +1) × (32/fSUB)
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UART Module Serial Interface
The device contains an integrated full-duplex asynchronous serial communications UART interface
that enables communication with external devices that contain a serial interface. The UART function
has many features and can transmit and receive data serially by transferring a frame of data with
eight or nine data bits per transmission as well as being able to detect errors when the data is
overwritten or incorrectly framed. The UART function possesses its own internal interrupt which
can be used to indicate when a reception occurs or when a transmission terminates.
The integrated UART function contains the following features:
• Full-duplex, Universal Asynchronous Receiver and Transmitter (UART) communication
• 8 or 9 bits character length
• Even, odd or no parity options
• One or two stop bits
• Baud rate generator with 8-bit prescaler
• Parity, framing, noise and overrun error detection
• Support for interrupt on address detect (last character bit=1)
• Transmitter and receiver enabled independently
• 2-byte Deep FIFO Receive Data Buffer
• Transmit and receive interrupts
• Transmit and Receive Multiple Interrupt Generation Sources:
♦♦
Transmitter Empty
♦♦
Transmitter Idle
♦♦
Receiver Full
♦♦
Receiver Overrun
♦♦
Address Mode Detect
♦♦
RX pin Wake-up
UART External Interface
To communicate with an external serial interface, the internal UART has two external pins known
as TX and RX. The TX pin is the UART transmitter pin, which can be used as a general purpose I/O
or other pin-shared functional pin if the pin is not configured as a UART transmitter, which occurs
when the TXEN bit in the UCR2 control register is equal to zero. Similarly, the RX pin is the UART
receiver pin, which can also be used as a general purpose I/O or other pin-shared functional pin, if
the pin is not configured as a receiver, which occurs if the RXEN bit in the UCR2 register is equal to
zero. Along with the UARTEN bit, the TXEN and RXEN bits, if set, will automatically setup these
I/O or other pin-shared functional pins to their respective TX output and RX input conditions and
disable any pull-high resistor option which may exist on the RX pin.
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UART Data Transfer Scheme
The block diagram shows the overall data transfer structure arrangement for the UART. The actual
data to be transmitted from the MCU is first transferred to the TXR register by the application
program. The data will then be transferred to the Transmit Shift Register from where it will be
shifted out, LSB first, onto the TX pin at a rate controlled by the Baud Rate Generator. Only the
TXR register is mapped onto the MCU Data Memory, the Transmit Shift Register is not mapped and
is therefore inaccessible to the application program.
Data to be received by the UART is accepted on the external RX pin, from where it is shifted in,
LSB first, to the Receiver Shift Register at a rate controlled by the Baud Rate Generator. When
the shift register is full, the data will then be transferred from the shift register to the internal RXR
register, where it is buffered and can be manipulated by the application program. Only the RXR
register is mapped onto the MCU Data Memory, the Receiver Shift Register is not mapped and is
therefore inaccessible to the application program.
It should be noted that the actual register for data transmission and reception, although referred to
in the text, and in application programs, as separate TXR and RXR registers, only exists as a single
shared register in the Data Memory. This shared register known as the TXR/RXR register is used for
both data transmission and data reception.
M�B
T�ans�itte� �hift Registe�
………………………… L�B
TX Pin
RX Pin
M�B
Receive� �hift Registe�
…………………………
L�B
CLK
CLK
Baud Rate
Gene�ato�
TXR Registe�
RXR Registe�
Buffe�
MCU Data Bus
UART Data Transfer Scheme
UART Status and Control Registers
There are five control registers associated with the UART function. The USR, UCR1 and UCR2
registers control the overall function of the UART, while the BRG register controls the Baud rate.
The actual data to be transmitted and received on the serial interface is managed through the TXR/
RXR data registers.
Bit
Register
Name
7
6
5
4
3
2
1
0
USR
PERR
NF
FERR
OERR
RIDLE
RXIF
TIDLE
TXIF
UCR1
UARTEN
BNO
PREN
PRT
STOPS
TXBRK
RX8
TX8
UCR2
TXEN
RXEN
BRGH
ADDEN
WAKE
RIE
TIIE
TEIE
TXR/RXR
TXRX7
TXRX6
TXRX5
TXRX4
TXRX3
TXRX2
TXRX1
TXRX0
BRG
BRG7
BRG6
BRG5
BRG4
BRG3
BRG2
BRG1
BRG0
UART Register Summary
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A/D 8-Bit Flash MCU with EEPROM
USR register
The USR register is the status register for the UART, which can be read by the program to determine
the present status of the UART. All flags within the USR register are read only. Further explanation
on each of the flags is given below:
Bit
7
6
5
4
3
2
1
0
Name
PERR
NF
FERR
OERR
RIDLE
RXIF
TIDLE
TXIF
R/W
R
R
R
R
R
R
R
R
POR
0
0
0
0
1
0
1
1
Bit 7PERR: Parity error flag
0: No parity error is detected
1: Parity error is detected
The PERR flag is the parity error flag. When this read only flag is “0”, it indicates a
parity error has not been detected. When the flag is “1”, it indicates that the parity of
the received word is incorrect. This error flag is applicable only if Parity mode (odd or
even) is selected. The flag can also be cleared by a software sequence which involves
a read to the status register USR followed by an access to the RXR data register.
Bit 6NF: Noise flag
0: No noise is detected
1: Noise is detected
The NF flag is the noise flag. When this read only flag is "0", it indicates no noise
condition. When the flag is "1", it indicates that the UART has detected noise on the
receiver input. The NF flag is set during the same cycle as the RXIF flag but will not
be set in the case of as overrun. The NF flag can be cleared by a software sequence
which will involve a read to the status register USR followed by an access to the RXR
data register.
Bit 5FERR: Framing error flag
0: No framing error is detected
1: Framing error is detected
The FERR flag is the framing error flag. When this read only flag is “0”, it indicates
that there is no framing error. When the flag is “1”, it indicates that a framing error
has been detected for the current character. The flag can also be cleared by a software
sequence which will involve a read to the status register USR followed by an access to
the RXR data register.
Bit 4OERR: Overrun error flag
0: No overrun error is detected
1: Overrun error is detected
The OERR flag is the overrun error flag which indicates when the receiver buffer has
overflowed. When this read only flag is “0”, it indicates that there is no overrun error.
When the flag is “1”, it indicates that an overrun error occurs which will inhibit further
transfers to the RXR receive data register. The flag is cleared by a software sequence,
which is a read to the status register USR followed by an access to the RXR data
register.
Bit 3RIDLE: Receiver status
0: Data reception is in progress (data being received)
1: No data reception is in progress (receiver is idle)
The RIDLE flag is the receiver status flag. When this read only flag is “0”, it indicates
that the receiver is between the initial detection of the start bit and the completion of
the stop bit. When the flag is “1”, it indicates that the receiver is idle. Between the
completion of the stop bit and the detection of the next start bit, the RIDLE bit is “1”
indicating that the UART receiver is idle and the RX pin stays in logic high condition.
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A/D 8-Bit Flash MCU with EEPROM
Bit 2RXIF: Receive RXR data register status
0: RXR data register is empty
1: RXR data register has available data
The RXIF flag is the receive data register status flag. When this read only flag is “0”,
it indicates that the RXR read data register is empty. When the flag is “1”, it indicates
that the RXR read data register contains new data. When the contents of the shift
register are transferred to the RXR register, an interrupt is generated if RIE=1 in the
UCR2 register. If one or more errors are detected in the received word, the appropriate
receive-related flags NF, FERR, and/or PERR are set within the same clock cycle. The
RXIF flag is cleared when the USR register is read with RXIF set, followed by a read
from the RXR register, and if the RXR register has no data available.
Bit 1TIDLE: Transmission idle
0: Data transmission is in progress (data being transmitted)
1: No data transmission is in progress (transmitter is idle)
The TIDLE flag is known as the transmission complete flag. When this read only
flag is “0”, it indicates that a transmission is in progress. This flag will be set to “1”
when the TXIF flag is “1” and when there is no transmit data or break character being
transmitted. When TIDLE is equal to “1”, the TX pin becomes idle with the pin state
in logic high condition. The TIDLE flag is cleared by reading the USR register with
TIDLE set and then writing to the TXR register. The flag is not generated when a data
character or a break is queued and ready to be sent.
Bit 0TXIF: Transmit TXR data register status
0: Character is not transferred to the transmit shift register
1: Character has transferred to the transmit shift register (TXR data register is
empty)
The TXIF flag is the transmit data register empty flag. When this read only flag is “0”,
it indicates that the character is not transferred to the transmitter shift register. When
the flag is “1”, it indicates that the transmitter shift register has received a character
from the TXR data register. The TXIF flag is cleared by reading the UART status
register (USR) with TXIF set and then writing to the TXR data register. Note that
when the TXEN bit is set, the TXIF flag bit will also be set since the transmit data
register is not yet full.
UCR1 register
The UCR1 register together with the UCR2 register are the two UART control registers that are used
to set the various options for the UART function, such as overall on/off control, parity control, data
transfer bit length etc. Further explanation on each of the bits is given below:
Bit
7
6
5
4
3
2
1
0
Name
UARTEN
BNO
PREN
PRT
STOPS
TXBRK
RX8
TX8
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
W
POR
0
0
0
0
0
0
x
0
“x” unknown
Bit 7UARTEN: UART function enable control
0: Disable UART. TX and RX pins are as I/O or other pin-shared functional pins
1: Enable UART. TX and RX pins function as UART pins
The UARTEN bit is the UART enable bit. When this bit is equal to “0”, the UART
will be disabled and the RX pin as well as the TX pin will be as General Purpose I/O
or other pin-shared functional pins. When the bit is equal to “1”, the UART will be
enabled and the TX and RX pins will function as defined by the TXEN and RXEN
enable control bits.
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When the UART is disabled, it will empty the buffer so any character remaining in
the buffer will be discarded. In addition, the value of the baud rate counter will be
reset. If the UART is disabled, all error and status flags will be reset. Also the TXEN,
RXEN, TXBRK, RXIF, OERR, FERR, PERR and NF bits will be cleared, while the
TIDLE, TXIF and RIDLE bits will be set. Other control bits in UCR1, UCR2 and
BRG registers will remain unaffected. If the UART is active and the UARTEN bit is
cleared, all pending transmissions and receptions will be terminated and the module
will be reset as defined above. When the UART is re-enabled, it will restart in the
same configuration.
Bit 6BNO: Number of data transfer bits selection
0: 8-bit data transfer
1: 9-bit data transfer
This bit is used to select the data length format, which can have a choice of either
8-bit or 9-bit format. When this bit is equal to “1”, a 9-bit data length format will be
selected. If the bit is equal to “0”, then an 8-bit data length format will be selected. If
9-bit data length format is selected, then bits RX8 and TX8 will be used to store the 9th
bit of the received and transmitted data respectively.
Bit 5PREN: Parity function enable control
0: Parity function is disabled
1: Parity function is enabled
This is the parity enable bit. When this bit is equal to “1”, the parity function will be
enabled. If the bit is equal to “0”, then the parity function will be disabled. Replace the
most significant bit position with a parity bit.
Bit 4PRT: Parity type selection bit
0: Even parity for parity generator
1: Odd parity for parity generator
This bit is the parity type selection bit. When this bit is equal to “1”, odd parity type
will be selected. If the bit is equal to “0”, then even parity type will be selected.
Bit 3STOPS: Number of Stop bits selection
0: One stop bit format is used
1: Two stop bits format is used
This bit determines if one or two stop bits are to be used. When this bit is equal to “1”,
two stop bits are used. If this bit is equal to “0”, then only one stop bit is used.
Bit 2TXBRK: Transmit break character
0: No break character is transmitted
1: Break characters transmit
The TXBRK bit is the Transmit Break Character bit. When this bit is “0”, there are
no break characters and the TX pin operates normally. When the bit is “1”, there are
transmit break characters and the transmitter will send logic zeros. When this bit is
equal to “1”, after the buffered data has been transmitted, the transmitter output is held
low for a minimum of a 13-bit length and until the TXBRK bit is reset.
Bit 1RX8: Receive data bit 8 for 9-bit data transfer format (read only)
This bit is only used if 9-bit data transfers are used, in which case this bit location will
store the 9th bit of the received data known as RX8. The BNO bit is used to determine
whether data transfers are in 8-bit or 9-bit format.
Bit 0TX8: Transmit data bit 8 for 9-bit data transfer format (write only)
This bit is only used if 9-bit data transfers are used, in which case this bit location
will store the 9th bit of the transmitted data known as TX8. The BNO bit is used to
determine whether data transfers are in 8-bit or 9-bit format.
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UCR2 register
The UCR2 register is the second of the two UART control registers and serves several purposes. One
of its main functions is to control the basic enable/disable operation of the UART Transmitter and
Receiver as well as enabling the various UART interrupt sources. The register also serves to control
the baud rate speed, receiver wake-up enable and the address detect enable. Further explanation on
each of the bits is given below:
Bit
7
6
5
4
3
2
1
0
Name
TXEN
RXEN
BRGH
ADDEN
WAKE
R/W
R/W
R/W
R/W
R/W
R/W
RIE
TIIE
TEIE
R/W
R/W
POR
0
0
0
0
0
0
R/W
0
0
Bit 7TXEN: UART Transmitter enabled control
0: UART transmitter is disabled
1: UART transmitter is enabled
The bit named TXEN is the Transmitter Enable Bit. When this bit is equal to “0”, the
transmitter will be disabled with any pending data transmissions being aborted. In
addition the buffers will be reset. In this situation the TX pin will be used as an I/O or
other pin-shared functional pin.
If the TXEN bit is equal to “1” and the UARTEN bit is also equal to “1”, the
transmitter will be enabled and the TX pin will be controlled by the UART. Clearing
the TXEN bit during a transmission will cause the data transmission to be aborted and
will reset the transmitter. If this situation occurs, the TX pin will be used as an I/O or
other pin-shared functional pin.
Bit 6RXEN: UART Receiver enabled control
0: UART receiver is disabled
1: UART receiver is enabled
The bit named RXEN is the Receiver Enable Bit. When this bit is equal to “0”, the
receiver will be disabled with any pending data receptions being aborted. In addition
the receive buffers will be reset. In this situation the RX pin will be used as an I/O or
other pin-shared functional pin. If the RXEN bit is equal to “1” and the UARTEN bit
is also equal to “1”, the receiver will be enabled and the RX pin will be controlled by
the UART. Clearing the RXEN bit during a reception will cause the data reception to
be aborted and will reset the receiver. If this situation occurs, the RX pin will be used
as an I/O or other pin-shared functional pin.
Bit 5BRGH: Baud Rate speed selection
0: Low speed baud rate
1: High speed baud rate
The bit named BRGH selects the high or low speed mode of the Baud Rate Generator.
This bit, together with the value placed in the baud rate register BRG, controls the
Baud Rate of the UART. If this bit is equal to “1”, the high speed mode is selected. If
the bit is equal to “0”, the low speed mode is selected.
Bit 4ADDEN: Address detect function enable control
0: Address detect function is disabled
1: Address detect function is enabled
The bit named ADDEN is the address detect function enable control bit. When this
bit is equal to “1”, the address detect function is enabled. When it occurs, if the 8th
bit, which corresponds to RX7 if BNO=0 or the 9th bit, which corresponds to RX8 if
BNO=1, has a value of “1”, then the received word will be identified as an address,
rather than data. If the corresponding interrupt is enabled, an interrupt request will be
generated each time the received word has the address bit set, which is the 8th or 9th
bit depending on the value of BNO. If the address bit known as the 8th or 9th bit of the
received word is “0” with the address detect function being enabled, an interrupt will
not be generated and the received data will be discarded.
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Bit 3WAKE: RX pin falling edge wake-up function enable control
0: RX pin wake-up function is disabled
1: RX pin wake-up function is enabled
This bit enables or disables the receiver wake-up function. If this bit is equal to “1”
and the MCU is in IDLE or SLEEP mode, a falling edge on the RX input pin will
wake-up the device. Please reference the UART RX pin wake-up functions in different
operating mode for the detail. If this bit is equal to “0” and the MCU is in IDLE or
SLEEP mode, any edge transitions on the RX pin will not wake-up the device.
Bit 2RIE: Receiver interrupt enable control
0: Receiver related interrupt is disabled
1: Receiver related interrupt is enabled
This bit enables or disables the receiver interrupt. If this bit is equal to “1” and when
the receiver overrun flag OERR or receive data available flag RXIF is set, the UART
interrupt request flag will be set. If this bit is equal to “0”, the UART interrupt request
flag will not be influenced by the condition of the OERR or RXIF flags.
Bit 1TIIE: Transmitter Idle interrupt enable control
0: Transmitter idle interrupt is disabled
1: Transmitter idle interrupt is enabled
This bit enables or disables the transmitter idle interrupt. If this bit is equal to “1” and
when the transmitter idle flag TIDLE is set, due to a transmitter idle condition, the
UART interrupt request flag will be set. If this bit is equal to “0”, the UART interrupt
request flag will not be influenced by the condition of the TIDLE flag.
Bit 0TEIE: Transmitter Empty interrupt enable control
0: Transmitter empty interrupt is disabled
1: Transmitter empty interrupt is enabled
This bit enables or disables the transmitter empty interrupt. If this bit is equal to “1”
and when the transmitter empty flag TXIF is set, due to a transmitter empty condition,
the UART interrupt request flag will be set. If this bit is equal to “0”, the UART
interrupt request flag will not be influenced by the condition of the TXIF flag.
TXR/RXR register
Bit
7
6
5
4
3
2
1
0
Name
TXRX7
TXRX6
TXRX5
TXRX4
TXRX3
TXRX2
TXRX1
TXRX0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
x
x
x
x
x
x
x
x
“x” unknown
Bit 7~0TXRX7~TXRX0: UART Transmit/Receive Data bit 7 ~ bit 0
BRG Register
Bit
7
6
5
4
3
2
1
0
Name
BRG7
BRG6
BRG5
BRG4
BRG3
BRG2
BRG1
BRG0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
x
x
x
x
x
x
x
x
“x” unknown
Bit 7~0BRG7~BRG0: Baud Rate values
By programming the BRGH bit in UCR2 Register which allows selection of the
related formula described above and programming the required value in the BRG
register, the required baud rate can be setup.
Note: Baud rate= fSYS/[64×(N+1)] if BRGH=0.
Baud rate= fSYS/[16×(N+1)] if BRGH=1.
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Baud Rate Generator
To setup the speed of the serial data communication, the UART function contains its own dedicated
baud rate generator. The baud rate is controlled by its own internal free running 8-bit timer, the
period of which is determined by two factors. The first of these is the value placed in the baud rate
register BRG and the second is the value of the BRGH bit with the control register UCR2. The
BRGH bit decides if the baud rate generator is to be used in a high speed mode or low speed mode,
which in turn determines the formula that is used to calculate the baud rate. The value N in the BRG
register which is used in the following baud rate calculation formula determines the division factor.
Note that N is the decimal value placed in the BRG register and has a range of between 0 and 255.
UCR2 BRGH Bit
0
1
Baud Rate (BR)
fSYS /[64 (N+1)]
fSYS /[16 (N+1)]
By programming the BRGH bit which allows selection of the related formula and programming the
required value in the BRG register, the required baud rate can be setup. Note that because the actual
baud rate is determined using a discrete value, N, placed in the BRG register, there will be an error
associated between the actual and requested value. The following example shows how the BRG
register value N and the error value can be calculated.
Calculating the register and error values
For a clock frequency of 4MHz, and with BRGH set to “0” determine the BRG register value N, the
actual baud rate and the error value for a desired baud rate of 4800.
From the above table the desired baud rate BR = fSYS /[64 (N+1)]
Re-arranging this equation gives N = [fSYS /(BR×64)] - 1
Giving a value for N = [4000000 /(4800×64)] - 1 = 12.0208
To obtain the closest value, a decimal value of 12 should be placed into the BRG register. This gives
an actual or calculated baud rate value of BR = 4000000 /[64×(12 + 1)] = 4808
Therefore the error is equal to (4808 - 4800) /4800 = 0.16%
The following tables show actual values of baud rate and error values for the two values of BRGH.
Baud Rate
K/BPS
Baud Rates for BRGH=0
fSYS = 16 MHz
BRG
Kbaud
fSYS = 20 MHz
Error (%)
BRG
Kbaud
Error (%)
0.3
—
—
—
—
—
—
1.2
207
1.202
0.16
259
1.202
0.16
2.4
103
2.404
0.16
129
2.404
0.16
4.8
51
4.808
0.16
64
4.808
0.16
9.6
25
9.615
0.16
32
9.470
-1.36
19.2
12
19.231
0.16
15
19.531
1.73
38.4
6
35.714
-6.99
7
39.063
1.73
57.6
3
62.5
8.51
4
62.5
8.51
115.2
1
125
8.51
2
104.17
-9.58
250
0
250
0
0
312.5
25
Baud Rates and Error Values for BRGH = 0
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Baud Rate
K/BPS
Baud Rates for BRGH=1
fSYS = 16 MHz
fSYS = 20 MHz
BRG
Kbaud
Error (%)
BRG
Kbaud
Error (%)
0.3
—
—
—
—
—
—
1.2
—
—
—
—
—
—
2.4
—
—
—
—
—
—
4.8
207
4.808
0.16
—
—
—
9.6
103
9.615
0.16
129
9.615
0.16
19.2
51
19.231
0.16
64
19.231
0.16
38.4
25
38.462
0.16
32
37.879
-1.36
57.6
16
58.824
2.12
21
56.818
-1.35
115.2
8
111.11
-3.55
10
113.636
-1.36
250
3
250
0
4
250
0
Baud Rates and Error Values for BRGH = 1
UART Setup and Control
For data transfer, the UART function utilizes a non-return-to-zero, more commonly known as NRZ,
format. This is composed of one start bit, eight or nine data bits, and one or two stop bits. Parity
is supported by the UART hardware, and can be setup to be even, odd or no parity. For the most
common data format, 8 data bits along with no parity and one stop bit, denoted as 8, N, 1, is used
as the default setting, which is the setting at power-on. The number of data bits and stop bits, along
with the parity, are setup by programming the corresponding BNO, PRT, PREN, and STOPS bits
in the UCR1 register. The baud rate used to transmit and receive data is setup using the internal
8-bit baud rate generator, while the data is transmitted and received LSB first. Although the UART
transmitter and receiver are functionally independent, they both use the same data format and baud
rate. In all cases stop bits will be used for data transmission.
Enabling/disabling the UART
The basic on/off function of the internal UART function is controlled using the UARTEN bit in the
UCR1 register. If the UARTEN, TXEN and RXEN bits are set, then these two UART pins will act
as normal TX output pin and RX input pin respectively. If no data is being transmitted on the TX
pin, then it will default to a logic high value.
Clearing the UARTEN bit will disable the TX and RX pins and allow these two pins to be used as
normal I/O or other pin-shared functional pins. When the UART function is disabled the buffer will
be reset to an empty condition, at the same time discarding any remaining residual data. Disabling
the UART will also reset the error and status flags with bits TXEN, RXEN, TXBRK, RXIF, OERR,
FERR, PERR and NF being cleared while bits TIDLE, TXIF and RIDLE will be set. The remaining
control bits in the UCR1, UCR2 and BRG registers will remain unaffected. If the UARTEN bit in
the UCR1 register is cleared while the UART is active, then all pending transmissions and receptions
will be immediately suspended and the UART will be reset to a condition as defined above. If the
UART is then subsequently re-enabled, it will restart again in the same configuration.
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Data, parity and stop bit selection
The format of the data to be transferred is composed of various factors such as data bit length,
parity on/off, parity type, address bits and the number of stop bits. These factors are determined by
the setup of various bits within the UCR1 register. The BNO bit controls the number of data bits
which can be set to either 8 or 9, the PRT bit controls the choice of odd or even parity, the PREN
bit controls the parity on/off function and the STOPS bit decides whether one or two stop bits are to
be used. The following table shows various formats for data transmission. The address bit identifies
the frame as an address character. The number of stop bits, which can be either one or two, is
independent of the data length.
Start Bit
Data Bits
Address Bits
Parity Bits
Stop Bit
Example of 8-bit Data Formats
1
8
0
0
1
1
7
0
1
1
1
7
1
0
1
Example of 9-bit Data Formats
1
9
0
0
1
1
8
0
1
1
1
8
1
0
1
Transmitter Receiver Data Format
The following diagram shows the transmit and receive waveforms for both 8-bit and 9-bit data
formats.
UART transmitter
Data word lengths of either 8 or 9 bits, can be selected by programming the BNO bit in the UCR1
register. When BNO bit is set, the word length will be set to 9 bits. In this case the 9th bit, which
is the MSB, needs to be stored in the TX8 bit in the UCR1 register. At the transmitter core lies the
Transmitter Shift Register, more commonly known as the TSR, whose data is obtained from the
transmit data register, which is known as the TXR register. The data to be transmitted is loaded
into this TXR register by the application program. The TSR register is not written to with new data
until the stop bit from the previous transmission has been sent out. As soon as this stop bit has been
transmitted, the TSR can then be loaded with new data from the TXR register, if it is available. It
should be noted that the TSR register, unlike many other registers, is not directly mapped into the
Data Memory area and as such is not available to the application program for direct read/write
operations. An actual transmission of data will normally be enabled when the TXEN bit is set, but
the data will not be transmitted until the TXR register has been loaded with data and the baud rate
generator has defined a shift clock source. However, the transmission can also be initiated by first
loading data into the TXR register, after which the TXEN bit can be set. When a transmission of
data begins, the TSR is normally empty, in which case a transfer to the TXR register will result in
an immediate transfer to the TSR. If during a transmission the TXEN bit is cleared, the transmission
will immediately cease and the transmitter will be reset. The TX output pin will then return to the I/O
or other pin-shared function.
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Transmitting data
When the UART is transmitting data, the data is shifted on the TX pin from the shift register, with
the least significant bit first. In the transmit mode, the TXR register forms a buffer between the
internal bus and the transmitter shift register. It should be noted that if 9-bit data format has been
selected, then the MSB will be taken from the TX8 bit in the UCR1 register. The steps to initiate a
data transfer can be summarized as follows:
• Make the correct selection of the BNO, PRT, PREN and STOPS bits to define the required word
length, parity type and number of stop bits.
• Setup the BRG register to select the desired baud rate.
• Set the TXEN bit to ensure that the TX pin is used as a UART transmitter pin.
• Access the USR register and write the data that is to be transmitted into the TXR register. Note
that this step will clear the TXIF bit.
• This sequence of events can now be repeated to send additional data.
It should be noted that when TXIF=0, data will be inhibited from being written to the TXR register.
Clearing the TXIF flag is always achieved using the following software sequence:
1. A USR register access
2. A TXR register write execution
The read-only TXIF flag is set by the UART hardware and if set indicates that the TXR register is
empty and that other data can now be written into the TXR register without overwriting the previous
data. If the TEIE bit is set then the TXIF flag will generate an interrupt.
During a data transmission, a write instruction to the TXR register will place the data into the TXR
register, which will be copied to the shift register at the end of the present transmission. When there
is no data transmission in progress, a write instruction to the TXR register will place the data directly
into the shift register, resulting in the commencement of data transmission, and the TXIF bit being
immediately set. When a frame transmission is complete, which happens after stop bits are sent
or after the break frame, the TIDLE bit will be set. To clear the TIDLE bit the following software
sequence is used:
1. A USR register access
2. A TXR register write execution
Note that both the TXIF and TIDLE bits are cleared by the same software sequence.
Transmit break
If the TXBRK bit is set then break characters will be sent on the next transmission. Break character
transmission consists of a start bit, followed by 13×N ‘0’ bits and stop bits, where N=1, 2, etc. If a
break character is to be transmitted then the TXBRK bit must be first set by the application program,
then cleared to generate the stop bits. Transmitting a break character will not generate a transmit
interrupt. Note that a break condition length is at least 13 bits long. If the TXBRK bit is continually
kept at a logic high level then the transmitter circuitry will transmit continuous break characters.
After the application program has cleared the TXBRK bit, the transmitter will finish transmitting the
last break character and subsequently send out one or two stop bits. The automatic logic highs at the
end of the last break character will ensure that the start bit of the next frame is recognized.
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UART receiver
The UART is capable of receiving word lengths of either 8 or 9 bits. If the BNO bit is set, the word
length will be set to 9 bits with the MSB being stored in the RX8 bit of the UCR1 register. At the
receiver core lies the Receive Serial Shift Register, commonly known as the RSR. The data which
is received on the RX external input pin, is sent to the data recovery block. The data recovery block
operating speed is 16 times that of the baud rate, while the main receive serial shifter operates at the
baud rate. After the RX pin is sampled for the stop bit, the received data in RSR is transferred to the
receive data register, if the register is empty. The data which is received on the external RX input pin
is sampled three times by a majority detect circuit to determine the logic level that has been placed
onto the RX pin. It should be noted that the RSR register, unlike many other registers, is not directly
mapped into the Data Memory area and as such is not available to the application program for direct
read/write operations.
Receiving data
When the UART receiver is receiving data, the data is serially shifted in on the external RX input
pin, LSB first. In the read mode, the RXR register forms a buffer between the internal bus and the
receiver shift register. The RXR register is a two byte deep FIFO data buffer, where two bytes can
be held in the FIFO while a third byte can continue to be received. Note that the application program
must ensure that the data is read from RXR before the third byte has been completely shifted
in, otherwise this third byte will be discarded and an overrun error OERR will be subsequently
indicated. The steps to initiate a data transfer can be summarized as follows:
• Make the correct selection of BNO, PRT, PREN and STOPS bits to define the word length, parity
type and number of stop bits.
• Setup the BRG register to select the desired baud rate.
• Set the RXEN bit to ensure that the RX pin is used as a UART receiver pin.
At this point the receiver will be enabled which will begin to look for a start bit.
When a character is received the following sequence of events will occur:
• The RXIF bit in the USR register will be set when RXR register has data available, at least one
character can be read.
• When the contents of the shift register have been transferred to the RXR register, then if the RIE
bit is set, an interrupt will be generated.
• If during reception, a frame error, noise error, parity error, or an overrun error has been detected,
then the error flags can be set.
The RXIF bit can be cleared using the following software sequence:
1. A USR register access
2. An RXR register read execution
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A/D 8-Bit Flash MCU with EEPROM
Receive break
Any break character received by the UART will be managed as a framing error. The receiver will
count and expect a certain number of bit times as specified by the values programmed into the BNO
and STOPS bits. If the break is much longer than 13 bit times, the reception will be considered as
complete after the number of bit times specified by BNO and STOPS. The RXIF bit is set, FERR
is set, zeros are loaded into the receive data register, interrupts are generated if appropriate and the
RIDLE bit is set. If a long break signal has been detected and the receiver has received a start bit,
the data bits and the invalid stop bit, which sets the FERR flag, the receiver must wait for a valid
stop bit before looking for the next start bit. The receiver will not make the assumption that the
break condition on the line is the next start bit. A break is regarded as a character that contains only
zeros with the FERR flag set. The break character will be loaded into the buffer and no further data
will be received until stop bits are received. It should be noted that the RIDLE read only flag will go
high when the stop bits have not yet been received. The reception of a break character on the UART
registers will result in the following:
• The framing error flag, FERR, will be set.
• The receive data register, RXR, will be cleared.
• The OERR, NF, PERR, RIDLE or RXIF flags will possibly be set.
Idle status
When the receiver is reading data, which means it will be in between the detection of a start bit and
the reading of a stop bit, the receiver status flag in the USR register, otherwise known as the RIDLE
flag, will have a zero value. In between the reception of a stop bit and the detection of the next start
bit, the RIDLE flag will have a high value, which indicates the receiver is in an idle condition.
Receiver interrupt
The read only receive interrupt flag RXIF in the USR register is set by an edge generated by the
receiver. An interrupt is generated if RIE=1, when a word is transferred from the Receive Shift
Register, RSR, to the Receive Data Register, RXR. An overrun error can also generate an interrupt if
RIE=1.
Managing receiver errors
Several types of reception errors can occur within the UART module, the following section describes
the various types and how they are managed by the UART.
Overrun Error – OERR flag
The RXR register is composed of a two byte deep FIFO data buffer, where two bytes can be held
in the FIFO register, while a third byte can continue to be received. Before the third byte has been
entirely shifted in, the data should be read from the RXR register. If this is not done, the overrun
error flag OERR will be consequently indicated.
In the event of an overrun error occurring, the following will happen:
• The OERR flag in the USR register will be set.
• The RXR contents will not be lost.
• The shift register will be overwritten.
• An interrupt will be generated if the RIE bit is set.
The OERR flag can be cleared by an access to the USR register followed by a read to the RXR
register.
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Noise Error – NF Flag
Over-sampling is used for data recovery to identify valid incoming data and noise. If noise is
detected within a frame the following will occur:
• The read only noise flag, NF, in the USR register will be set on the rising edge of the RXIF bit.
• Data will be transferred from the Shift register to the RXR register.
• No interrupt will be generated. However this bit rises at the same time as the RXIF bit which
itself generates an interrupt.
Note that the NF flag is reset by a USR register read operation followed by an RXR register read
operation.
Framing Error – FERR Flag
The read only framing error flag, FERR, in the USR register, is set if a zero is detected instead of
stop bits. If two stop bits are selected, both stop bits must be high, otherwise the FERR flag will be
set. The FERR flag is buffered along with the received data and is cleared on any reset.
Parity Error – PERR Flag
The read only parity error flag, PERR, in the USR register, is set if the parity of the received word is
incorrect. This error flag is only applicable if the parity is enabled, PREN = 1, and if the parity type,
odd or even is selected. The read only PERR flag is buffered along with the received data bytes. It is
cleared on any reset. It should be noted that the FERR and PERR flags are buffered along with the
corresponding word and should be read before reading the data word.
UART Module Interrupt Structure
Several individual UART conditions can generate a UART interrupt. When these conditions exist,
a low pulse will be generated to get the attention of the microcontroller. These conditions are a
transmitter data register empty, transmitter idle, receiver data available, receiver overrun, address
detect and an RX pin wake-up. When any of these conditions are created, if its corresponding
interrupt control is enabled and the stack is not full, the program will jump to its corresponding
interrupt vector where it can be serviced before returning to the main program. Four of these
conditions have the corresponding USR register flags which will generate a UART interrupt if its
associated interrupt enable control bit in the UCR2 register is set. The two transmitter interrupt
conditions have their own corresponding enable control bits, while the two receiver interrupt
conditions have a shared enable control bit. These enable bits can be used to mask out individual
UART interrupt sources.
The address detect condition, which is also a UART interrupt source, does not have an associated
flag, but will generate a UART interrupt when an address detect condition occurs if its function
is enabled by setting the ADDEN bit in the UCR2 register. An RX pin wake-up, which is also a
UART interrupt source, does not have an associated flag, but will generate a UART interrupt if the
microcontroller is woken up by a falling edge on the RX pin, if the WAKE and RIE bits in the UCR
register are set. Note that in the event of an RX wake-up interrupt occurring, there will be a certain
period of delay, commonly known as the System Start-up Time, for the oscillator to restart and
stabilize before the system resumes normal operation.
Note that the USR register flags are read only and cannot be cleared or set by the application
program, neither will they be cleared when the program jumps to the corresponding interrupt
servicing routine, as is the case for some of the other interrupts. The flags will be cleared
automatically when certain actions are taken by the UART, the details of which are given in the
UART register section. The overall UART interrupt can be disabled or enabled by the related
interrupt enable control bits in the interrupt control registers of the microcontroller to decide whether
the interrupt requested by the UART module is masked out or allowed.
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A/D 8-Bit Flash MCU with EEPROM
USR Register
UCR2 Register
Transmitter Empty
Flag TXIF
TEIE
0
1
Transmitter Idle
Flag TIDLE
TIIE
0
1
RIE
0
1
Receiver Overrun
Flag OERR
OR
Receiver Data
Available RXIF
RX Pin
Wake-up
WAKE
ADDEN
UART Interrupt
Request Flag
UARF
To MCU Interrupt
Controller
0
1
0
1
0
1
RX7 if BNO=0
RX8 if BNO=1
UCR2 Register
UART Interrupt Scheme
Address detect mode
Setting the Address Detect Mode bit, ADDEN, in the UCR2 register, enables this special mode. If
this bit is enabled then an additional qualifier will be placed on the generation of a Receiver Data
Available interrupt, which is requested by the RXIF flag. If the ADDEN bit is enabled, then when
data is available, an interrupt will only be generated, if the highest received bit has a high value.
Note that the MFE, URE and EMI interrupt enable bits must also be enabled for correct interrupt
generation. This highest address bit is the 9th bit if BNO=1 or the 8th bit if BNO=0. If this bit is high,
then the received word will be defined as an address rather than data. A Data Available interrupt will
be generated every time the last bit of the received word is set. If the ADDEN bit is not enabled, then
a Receiver Data Available interrupt will be generated each time the RXIF flag is set, irrespective of
the data last bit status. The address detect mode and parity enable are mutually exclusive functions.
Therefore if the address detect mode is enabled, then to ensure correct operation, the parity function
should be disabled by resetting the parity enable bit to zero.
ADDEN
0
1
Bit 9 if BNO=1, Bit 8 if BNO=0
UART Interrupt Generated
0
√
1
√
0
×
1
√
ADDEN Bit Function
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UART Module Power Down and Wake-up
When the fSYS is off, the UART will cease to function. All clock sources to the module are shutdown.
If the fSYS is off while a transmission is still in progress, then the transmission will be paused until
the UART clock source derived from the microcontroller is activated. In a similar way, if the MCU
enters the Power Down Mode while receiving data, then the reception of data will likewise be
paused. When the MCU enters the Power Down Mode, note that the USR, UCR1, UCR2, transmit
and receive registers, as well as the BRG register will not be affected. It is recommended to make
sure first that the UART data transmission or reception has been finished before the microcontroller
enters the Power Down mode.
The UART function contains a receiver RX pin wake-up function, which is enabled or disabled
by the WAKE bit in the UCR2 register. If this bit, along with the UART enable bit, UARTEN, the
receiver enable bit, RXEN and the receiver interrupt bit, RIE, are all set before the MCU enters
the Power Down Mode, then a falling edge on the RX pin will wake up the MCU from the Power
Down Mode. Note that as it takes certain system clock cycles after a wake-up, before normal
microcontroller operation resumes, any data received during this time on the RX pin will be ignored.
For a UART wake-up interrupt to occur, in addition to the bits for the wake-up being set, the global
interrupt enable bit, EMI, and the UART interrupt enable bit, UARE, must also be set. If these two
bits are not set then only a wake up event will occur and no interrupt will be generated. Note also
that as it takes certain system clock cycles after a wake-up before normal microcontroller resumes,
the UART interrupt will not be generated until after this time has elapsed.
Interrupts
Interrupts are an important part of any microcontroller system. When an external event or an
internal function such as a Timer Module or an A/D converter requires microcontroller attention,
their corresponding interrupt will enforce a temporary suspension of the main program allowing the
microcontroller to direct attention to their respective needs. The device contains an external interrupt
and internal interrupts functions. The external interrupt is generated by the action of the external
INTn pins, while the internal interrupts are generated by various internal functions such as the TMs,
Time Base, EEPROM, SIM, UART and the A/D converter.
Interrupt Registers
Overall interrupt control, which basically means the setting of request flags when certain
microcontroller conditions occur and the setting of interrupt enable bits by the application program,
is controlled by a series of registers, located in the Special Purpose Data Memory, as shown in
the accompanying table. The number of registers depends upon the device chosen but fall into
three categories. The first is the INTC0~INTC3 registers which setup the primary interrupts, the
second is the MFI0~MFI2 registers which setup the Multi-function interrupts. Finally there are
INTEG0~INTEG1 registers to setup the external interrupt trigger edge type.
Each register contains a number of enable bits to enable or disable individual registers as well as
interrupt flags to indicate the presence of an interrupt request. The naming convention of these
follows a specific pattern. First is listed an abbreviated interrupt type, then the (optional) number of
that interrupt followed by either an “E” for enable/disable bit or “F” for request flag.
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Function
Enable Bit
Request Flag
EMI
—
INTn Pin
INTnE
INTnF
UART
UARE
UARF
Time Base
TBnE
TBnF
A/D Converter
ADE
ADF
Multi-function
MFnE
MFnF
Global
Notes
—
n=0~5
—
n=0 or 1
—
n=0~2
EEPROM
DEE
DEF
—
SIM
SIME
SIMF
—
CTMPE
CTMPF
CTMAE
CTMAF
STMPE
STMPF
STMAE
STMAF
PTMnPE
PTMnPF
PTMnAE
PTMnAF
CTM
STM
PTM
—
—
n=0 or 1
Interrupt Register Bit Naming Conventions
Bit
Register
Name
7
6
5
4
3
2
1
0
INTEG0
INT3S1
INT3S0
INT2S1
INT2S0
INT1S1
INT1S0
INT0S1
INT0S0
INTEG1
—
—
—
—
INT5S1
INT5S0
INT4S1
INT4S0
INTC0
—
INT2F
INT1F
INT0F
INT2E
INT1E
INT0E
EMI
INTC1
UARF
INT5F
INT4F
INT3F
UARE
INT5E
INT4E
INT3E
INTC2
ADF
MF2F
MF1F
MF0F
ADE
MF2E
MF1E
MF0E
INTC3
SIMF
DEF
TB1F
TB0F
SIME
DEE
TB1E
TB0E
MFI0
—
—
CTMAF
CTMPF
—
—
CTMAE
CTMPE
MFI1
LVF
—
STMAF
STMPF
LVE
—
STMAE
STMPE
MFI2
PTM1AF
PTM1PF
PTM0AF
PTM0PF
PTM1AE
PTM1PE
PTM0AE
PTM0PE
Interrupt Register Contents
INTEG0 Register
Rev. 1.00
Bit
7
6
5
4
3
2
1
0
Name
INT3S1
INT3S0
INT2S1
INT2S0
INT1S1
INT1S0
INT0S1
INT0S0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7 ~ 6
INT3S1, INT3S0: Defines INT3 interrupt active edge
00: Disabled Interrupt
01: Rising Edge Interrupt
10: Falling Edge Interrupt
11: Dual Edge Interrupt
Bit 5 ~ 4
INT2S1, INT2S0: Defines INT2 interrupt active edge
00: Disabled Interrupt
01: Rising Edge Interrupt
10: Falling Edge Interrupt
11: Dual Edge Interrupt
Bit 3 ~ 2
INT1S1, INT1S0: Defines INT1 interrupt active edge
00: Disabled Interrupt
01: Rising Edge Interrupt
10: Falling Edge Interrupt
11: Dual Edge Interrupt
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Bit 1 ~ 0
INT0S1, INT0S0: Defines INT0 interrupt active edge
00: Disabled Interrupt
01: Rising Edge Interrupt
10: Falling Edge Interrupt
11: Dual Edge Interrupt
INTEG1 Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
INT5S1
INT5S0
INT4S1
INT4S0
R/W
—
—
—
—
R/W
R/W
R/W
R/W
POR
—
—
—
—
0
0
0
0
Bit 7 ~ 4
Unimplemented, read as "0"
Bit 3 ~ 2
INT5S1, INT5S0: Defines INT5 interrupt active edge
00: Disabled Interrupt
01: Rising Edge Interrupt
10: Falling Edge Interrupt
11: Dual Edge Interrupt
Bit 1 ~ 0
INT4S1, INT4S0: Defines INT4 interrupt active edge
00: Disabled Interrupt
01: Rising Edge Interrupt
10: Falling Edge Interrupt
11: Dual Edge Interrupt
INTC0 Register
Bit
7
6
5
4
3
2
1
0
Name
—
INT2F
INT1F
INT0F
INT2E
INT1E
INT0E
EMI
R/W
—
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
—
0
0
0
0
0
0
0
Bit 7
Unimplemented, read as "0"
Bit 6INT2F: INT2 Interrupt Request Flag
0: No request
1: Interrupt request
Bit 5INT1F: INT1 Interrupt Request Flag
0: No request
1: Interrupt request
Bit 4INT0F: INT0 Interrupt Request Flag
0: No request
1: Interrupt request
Bit 3INT2E: INT2 Interrupt Control
0: Disable
1: Enable
Bit 2INT1E: INT1 Interrupt Control
0: Disable
1: Enable
Bit 1INT0E: INT0 Interrupt Control
0: Disable
1: Enable
Bit 0EMI: Global Interrupt Control
0: Disable
1: Enable
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INTC1 Register
Bit
7
6
5
4
3
2
1
0
Name
UARF
INT5F
INT4F
INT3F
UARE
INT5E
INT4E
INT3E
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7UARF: UART Interrupt Request Flag
0: No request
1: Interrupt request
Bit 6INT5F: INT5 Interrupt Request Flag
0: No request
1: Interrupt request
Bit 5INT4F: INT4 Interrupt Request Flag
0: No request
1: Interrupt request
Bit 4INT3F: INT3 Interrupt Request Flag
0: No request
1: Interrupt request
Bit 3UARE: UART Interrupt Control
0: Disable
1: Enable
Bit 2INT5E: INT5 Interrupt Control
0: Disable
1: Enable
Bit 1INT4E: INT4 Interrupt Control
0: Disable
1: Enable
Bit 0INT3E: INT3 Interrupt Control
0: Disable
1: Enable
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INTC2 Register
Bit
7
6
5
4
3
2
1
0
Name
ADF
MF2F
MF1F
MF0F
ADE
MF2E
MF1E
MF0E
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7ADF: A/D Converter Interrupt Request Flag
0: No request
1: Interrupt request
Bit 6MF2F: Multi-function 2 Interrupt Request Flag
0: No request
1: Interrupt request
Bit 5MF1F: Multi-function 1 Interrupt Request Flag
0: No request
1: Interrupt request
Bit 4MF0F: Multi-function 0 Interrupt Request Flag
0: No request
1: Interrupt request
Bit 3ADE: A/D Converter Interrupt Control
0: Disable
1: Enable
Bit 2MF2E: Multi-function 2 Interrupt Control
0: Disable
1: Enable
Bit 1MF1E: Multi-function 1 Interrupt Control
0: Disable
1: Enable
Bit 0 MF0E: Multi-function 0 Interrupt Control
0: Disable
1: Enable
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INTC3 Register
Bit
7
6
5
4
3
2
1
0
Name
SIMF
DEF
TB1F
TB0F
SIME
DEE
TB1E
TB0E
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7SIMF: Serial Interface Module Interrupt Request Flag
0: No request
1: Interrupt request
Bit 6DEF: Data EEPROM Interrupt Request Flag
0: No request
1: Interrupt request
Bit 5TB1F : Time Base 1 Interrupt Request Flag
0: No request
1: Interrupt request
Bit 4TB0F: Time Base 0 Interrupt Request Flag
0: No request
1: Interrupt request
Bit 3 SIME: Serial Interface Module Interrupt Control
0: Disable
1: Enable
Bit 2DEE: Data EEPROM Interrupt Control
0: Disable
1: Enable
Bit 1 TB1E : Time Base 1 Interrupt Control
0: Disable
1: Enable
Bit 0TB0E: Time Base 0 Interrupt Control
0: Disable
1: Enable
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MFI0 Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
CTMAF
CTMPF
—
—
CTMAE
CTMPE
R/W
—
—
R/W
R/W
—
—
R/W
R/W
POR
—
—
0
0
—
—
0
0
Bit 7 ~ 6
Unimplemented, read as "0"
Bit 5CTMAF: CTM Comparator A match interrupt request flag
0: No request
1: Interrupt request
Bit 4CTMPF: CTM Comparator P match interrupt request flag
0: No request
1: Interrupt request
Bit 3 ~ 2
Unimplemented, read as "0"
Bit 1CTMAE: CTM Comparator A match interrupt control
0: Disable
1: Enable
Bit 0CTMPE: CTM Comparator P match interrupt control
0: Disable
1: Enable
MFI1 Register
Bit
7
6
5
4
3
2
1
0
Name
LVF
—
STMAF
STMPF
LVE
—
STMAE
STMPE
R/W
R/W
—
R/W
R/W
R/W
—
R/W
R/W
POR
0
—
0
0
0
—
0
0
Bit 7LVF: LVD interrupt request flag
0: No request
1: Interrupt request
Bit 6
Unimplemented, read as "0"
Bit 5STMAF: STM Comparator A match interrupt request flag
0: No request
1: Interrupt request
Bit 4STMPF: STM Comparator P match interrupt request flag
0: No request
1: Interrupt request
Bit 3LVE: LVD interrupt control
0: Disable
1: Enable
Bit 2
Unimplemented, read as "0"
Bit 1STMAE: STM Comparator A match interrupt control
0: Disable
1: Enable
Bit 0STMPE: STM Comparator P match interrupt control
0: Disable
1: Enable
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MFI2 Register
Bit
7
6
5
4
Name
PTM1AF
PTM1PF
PTM0AF
PTM0PF
3
2
1
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
PTM1AE PTM1PE PTM0AE PTM0PE
Bit 7PTM1AF: PTM1 Comparator A match interrupt request flag
0: No request
1: Interrupt request
Bit 6PTM1PF: PTM1 Comparator P match interrupt request flag
0: No request
1: Interrupt request
Bit 5PTM0AF: PTM0 Comparator A match interrupt request flag
0: No request
1: Interrupt request
Bit 4PTM0PF: PTM0 Comparator P match interrupt request flag
0: No request
1: Interrupt request
Bit 3PTM1AE: PTM1 Comparator A match interrupt control
0: Disable
1: Enable
Bit2PTM1PE: PTM1 Comparator P match interrupt control
0: Disable
1: Enable
Bit 1PTM0AE: PTM0 Comparator A match interrupt control
0: Disable
1: Enable
Bit 0PTM0PE: PTM0 Comparator P match interrupt control
0: Disable
1: Enable
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Interrupt Operation
When the conditions for an interrupt event occur, such as a TM Comparator P or Comparator A
match or A/D conversion completion etc, the relevant interrupt request flag will be set. Whether
the request flag actually generates a program jump to the relevant interrupt vector is determined by
the condition of the interrupt enable bit. If the enable bit is set high then the program will jump to
its relevant vector; if the enable bit is zero then although the interrupt request flag is set an actual
interrupt will not be generated and the program will not jump to the relevant interrupt vector. The
global interrupt enable bit, if cleared to zero, will disable all interrupts.
When an interrupt is generated, the Program Counter, which stores the address of the next instruction
to be executed, will be transferred onto the stack. The Program Counter will then be loaded with a
new address which will be the value of the corresponding interrupt vector. The microcontroller will
then fetch its next instruction from this interrupt vector. The instruction at this vector will usually
be a “JMP” which will jump to another section of program which is known as the interrupt service
routine. Here is located the code to control the appropriate interrupt. The interrupt service routine
must be terminated with a “RETI”, which retrieves the original Program Counter address from
the stack and allows the microcontroller to continue with normal execution at the point where the
interrupt occurred.
The various interrupt enable bits, together with their associated request flags, are shown in the
accompanying diagrams with their order of priority. Some interrupt sources have their own
individual vector while others share the same multi-function interrupt vector. Once an interrupt
subroutine is serviced, all the other interrupts will be blocked, as the global interrupt enable bit,
EMI bit will be cleared automatically. This will prevent any further interrupt nesting from occurring.
However, if other interrupt requests occur during this interval, although the interrupt will not be
immediately serviced, the request flag will still be recorded.
If an interrupt requires immediate servicing while the program is already in another interrupt service
routine, the EMI bit should be set after entering the routine, to allow interrupt nesting. If the stack
is full, the interrupt request will not be acknowledged, even if the related interrupt is enabled, until
the Stack Pointer is decremented. If immediate service is desired, the stack must be prevented from
becoming full. In case of simultaneous requests, the accompanying diagram shows the priority that
is applied. All of the interrupt request flags when set will wake-up the device if it is in SLEEP or
IDLE Mode, however to prevent a wake-up from occurring the corresponding flag should be set
before the device is in SLEEP or IDLE Mode.
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EMI auto disabled in ISR
xxF
Legend
Request Flag, no auto reset in ISR
xxF
Request Flag, auto reset in ISR
xxE
Enable Bits
CTMP
CTMPF
CTMPE
CTMA
CTMAF
CTMAE
LVD
LVF
LVE
STMP
STMPF
STMPE
STMA
STMAF
STMAE
PTM0P
PTM0PF
PTM0PE
PTM0A
PTM0AF
PTM0AE
PTM1P
PTM1PF
PTM1PE
PTM1A
PTM1AF
PTM1AE
Interrupts contained within
Multi-Function Interrupts
Interrupt
Name
Request
Flags
Enable
Bits
Master
Enable
Vector
INT0 Pin
INT0F
INT0E
EMI
04H
INT1 Pin
INT1F
INT1E
EMI
08H
INT2 Pin
INT2F
INT2E
EMI
0CH
INT3 Pin
INT3F
INT3E
EMI
10H
INT4 Pin
INT4F
INT4E
EMI
14H
INT5 Pin
INT5F
INT5E
EMI
18H
UART
UARF
UARE
EMI
1CH
M. Funct. 0
MF0F
MF0E
EMI
20H
M. Funct. 1
MF1F
MF1E
EMI
24H
M. Funct. 2
MF2F
MF2E
EMI
28H
A/D
ADF
ADE
EMI
2CH
Time Base 0
TB0F
TB0E
EMI
30H
Time Base 1
TB1F
TB1E
EMI
34H
EEPROM
DEF
DEE
EMI
38H
SIM
SIMF
SIME
EMI
3CH
Priority
High
Low
Interrupt Structure
External Interrupt
The external interrupt is controlled by signal transitions on the pins INT0~INT5. An external
interrupt request will take place when the external interrupt request flag, INTnF, is set, which
will occur when a transition, whose type is chosen by the edge select bits, appears on the external
interrupt pin. To allow the program to branch to the interrupt vector address, the global interrupt
enable bit, EMI, and the external interrupt enable bit, INTnE, must first be set. Additionally the
correct interrupt edge type must be selected using the INTEGn register to enable the external
interrupt function and to choose the trigger edge type. As the external interrupt pin is pin-shared
with an I/O pin, it can only be configured as external interrupt pin if its external interrupt enable bit
in the corresponding interrupt register has been set. The pin must also be setup as an input by setting
the corresponding bit in the port control register. When the interrupt is enabled, the stack is not full
and the correct transition type appears on the external interrupt pin, a subroutine call to the external
interrupt vector, will take place. When the interrupt is serviced, the external interrupt request flag,
INTnF, will be automatically reset and the EMI bit will be automatically cleared to disable other
interrupts. Note that the pull-high resistor selection on the external interrupt pin will remain valid
even if the pin is used as an external interrupt input.
The INTEG0~INTEG1 registers are used to select the type of active edge that will trigger the
external interrupt. A choice of either rising or falling or both edge types can be chosen to trigger an
external interrupt. Note that the INTEG0~INTEG1 registers can also be used to disable the external
interrupt function.
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Multi-function Interrupt
Within this device there are up to three Multi-function interrupts. Unlike the other independent
interrupts, these interrupts have no independent source, but rather are formed from other existing
interrupt sources, namely the TM Interrupts and LVD interrupt.
A Multi-function interrupt request will take place when any of the Multi-function interrupt request
flags, MF0F~MF2F are set. The Multi-function interrupt flags will be set when any of their included
functions generate an interrupt request flag. To allow the program to branch to its respective interrupt
vector address, when the Multi-function interrupt is enabled and the stack is not full, and either one
of the interrupts contained within each of Multi-function interrupt occurs, a subroutine call to one of
the Multi-function interrupt vectors will take place. When the interrupt is serviced, the related MultiFunction request flag will be automatically reset and the EMI bit will be automatically cleared to
disable other interrupts.
However, it must be noted that, although the Multi-function Interrupt flags will be automatically
reset when the interrupt is serviced, the request flags from the original source of the Multi-function
interrupts, namely the TM Interrupts and LVD interrupt, will not be automatically reset and must be
manually reset by the application program.
A/D Converter Interrupt
The device contains an A/D converter which has its own independent interrupt. The A/D Converter
Interrupt is controlled by the termination of an A/D conversion process. An A/D Converter Interrupt
request will take place when the A/D Converter Interrupt request flag, ADF, is set, which occurs
when the A/D conversion process finishes. To allow the program to branch to its respective interrupt
vector address, the global interrupt enable bit, EMI, and A/D Interrupt enable bit, ADE, must first be
set. When the interrupt is enabled, the stack is not full and the A/D conversion process has ended, a
subroutine call to the A/D Converter Interrupt vector, will take place. When the interrupt is serviced,
the A/D Converter Interrupt flag, ADF, will be automatically cleared. The EMI bit will also be
automatically cleared to disable other interrupts.
Time Base Interrupts
The function of the Time Base Interrupts is to provide regular time signal in the form of an internal
interrupt. They are controlled by the overflow signals from their respective timer functions. When
these happens their respective interrupt request flags, TB0F or TB1F will be set. To allow the
program to branch to their respective interrupt vector addresses, the global interrupt enable bit, EMI
and Time Base enable bits, TB0E or TB1E, must first be set. When the interrupt is enabled, the stack
is not full and the Time Base overflows, a subroutine call to their respective vector locations will
take place. When the interrupt is serviced, the respective interrupt request flag, TB0F or TB1F, will
be automatically reset and the EMI bit will be cleared to disable other interrupts.
The purpose of the Time Base Interrupt is to provide an interrupt signal at fixed time periods. Their
clock sources originate from the internal clock source fTB. This fTB input clock passes through a
divider, the division ratio of which is selected by programming the appropriate bits in the TBC
register to obtain longer interrupt periods whose value ranges. The clock source that generates fTB,
which in turn controls the Time Base interrupt period, can originate from several different sources,
as shown in the System Operating Mode section.
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TBC Register
Bit
7
6
5
4
3
2
1
0
Name
TBON
TBCK
TB11
TB10
LXTLP
TB02
TB01
TB00
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
1
1
0
1
1
1
Bit 7TBON: TB0 and TB1 Control bit
0: Disable
1: Enable
Bit 6TBCK: Select fTB Clock
0: fTBC
1: fSYS/4
Bit 5 ~ 4
TB11 ~ TB10: Select Time Base 1 Time-out Period
00: 4096/fTB
01: 8192/fTB
10: 16384/fTB
11: 32768/fTB
Bit 3LXTLP: LXT Low Power Mode control
0: Disable (Quick Start Mode)
1: Enable (Low Power Mode)
Bit 2 ~ 0
TB02 ~ TB00: Select Time Base 0 Time-out Period
000: 28/fTB
001: 29/fTB
010: 210/fTB
011: 211/fTB
100: 212/fTB
101: 213/fTB
110: 214/fTB
111: 215/fTB
TB02~TB00
fSYS/4
LXT
LIRC
M
U
X
fTBC
M
U
X
÷28~215
Time Base 0 Interrupt
÷212~215
Time Base 1 Interrupt
fTB
TBCK bit
Configuration
Option
TB11~TB10
Time Base Interrupt
Serial Interface Module Interrupts
A SIM Interrupt request will take place when the SIM Interrupt request flag, SIMF, is set, which
occurs when a byte of data has been received or transmitted by the SIM interface. To allow the
program to branch to its respective interrupt vector address, the global interrupt enable bit, EMI,
and the Serial Interface Interrupt enable bit, SIME, must first be set. When the interrupt is enabled,
the stack is not full and a byte of data has been transmitted or received by the SIM interface, a
subroutine call to the respective Interrupt vector, will take place. When the interrupt is serviced, the
respective interrupt request flag, SIMF, will be automatically reset and the EMI bit will be cleared to
disable other interrupts.
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EEPROM Interrupt
An EEPROM Interrupt request will take place when the EEPROM Interrupt request flag, DEF, is set,
which occurs when an EEPROM Write cycle ends. To allow the program to branch to its respective
interrupt vector address, the global interrupt enable bit, EMI, and EEPROM Interrupt enable bit,
DEE, must first be set. When the interrupt is enabled, the stack is not full and an EEPROM Write
cycle ends, a subroutine call to the respective EEPROM Interrupt vector, will take place. When the
EEPROM Interrupt is serviced, the EMI bit will be automatically cleared to disable other interrupts,
and the EEPROM interrupt request flag, DEF, will also be automatically cleared.
TM Interrupts
The Compact, Standard and Periodic Type TMs each has two interrupts. All of the TM interrupts
are contained within the Multi-function Interrupts. For each of the Compact, Standard and Periodic
Type TMs there are two interrupt request flags xTMnPF and xTMnAF and two enable bits xTMnPE
and xTMnAE. A TM interrupt request will take place when any of the TM request flags are set, a
situation which occurs when a TM comparator P or comparator A match situation happens.
To allow the program to branch to its respective interrupt vector address, the global interrupt enable
bit, EMI, and the respective TM Interrupt enable bit, and associated Multi-function interrupt enable
bit, MFnF, must first be set. When the interrupt is enabled, the stack is not full and a TM comparator
match situation occurs, a subroutine call to the relevant TM Interrupt vector locations, will take
place. When the TM interrupt is serviced, the EMI bit will be automatically cleared to disable other
interrupts, however only the related MFnF flag will be automatically cleared. As the TM interrupt
request flags will not be automatically cleared, they have to be cleared by the application program.
LVD Interrupt
The Low Voltage Detector Interrupt is contained within the Multi-function Interrupt. An LVD
Interrupt request will take place when the LVD Interrupt request flag, LVF, is set, which occurs
when the Low Voltage Detector function detects a low power supply voltage. To allow the program
to branch to its respective interrupt vector address, the global interrupt enable bit, EMI, Low Voltage
Interrupt enable bit, LVE, and associated Multi-function interrupt enable bit, must first be set. When
the interrupt is enabled, the stack is not full and a low voltage condition occurs, a subroutine call to
the Multi-function Interrupt vector will take place. When the Low Voltage Interrupt is serviced, the
EMI bit will be automatically cleared to disable other interrupts, however only the Multi-function
interrupt request flag will be also automatically cleared. As the LVF flag will not be automatically
cleared, it has to be cleared by the application program.
UART Interrupt
Several individual UART conditions can generate a UART interrupt. When these conditions exist,
a low pulse will be generated to get the attention of the microcontroller. These conditions are a
transmitter data register empty, transmitter idle, receiver data available, receiver overrun, address
detect and an RX pin wake-up. To allow the program to branch to the respective interrupt vector
addresses, the global interrupt enable bit, EMI, and UART interrupt enable bit, UARE, must first
be set. When the interrupt is enabled, the stack is not full and any of these conditions are created,
a subroutine call to the UART Interrupt vector will take place. When the interrupt is serviced, the
UART Interrupt flag, UARF, will be automatically cleared. The EMI bit will also be automatically
cleared to disable other interrupts. However, the USR register flags will be cleared automatically
when certain actions are taken by the UART, the details of which are given in the UART section.
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Interrupt Wake-up Function
Each of the interrupt functions has the capability of waking up the microcontroller when in the
SLEEP or IDLE Mode. A wake-up is generated when an interrupt request flag changes from low to
high and is independent of whether the interrupt is enabled or not. Therefore, even though the device
is in the SLEEP or IDLE Mode and its system oscillator stopped, situations such as external edge
transitions on the external interrupt pin, a low power supply voltage or comparator input change may
cause their respective interrupt flag to be set high and consequently generate an interrupt. Care must
therefore be taken if spurious wake-up situations are to be avoided. If an interrupt wake-up function
is to be disabled then the corresponding interrupt request flag should be set high before the device
enters the SLEEP or IDLE Mode. The interrupt enable bits have no effect on the interrupt wake-up
function.
Programming Considerations
By disabling the relevant interrupt enable bits, a requested interrupt can be prevented from being
serviced, however, once an interrupt request flag is set, it will remain in this condition in the
interrupt register until the corresponding interrupt is serviced or until the request flag is cleared by
the application program.
Where a certain interrupt is contained within a Multi-function interrupt, then when the interrupt
service routine is executed, as only the Multi-function interrupt request flags, MF0F~MF2F, will
be automatically cleared, the individual request flag for the function needs to be cleared by the
application program.
It is recommended that programs do not use the “CALL” instruction within the interrupt service
subroutine. Interrupts often occur in an unpredictable manner or need to be serviced immediately.
If only one stack is left and the interrupt is not well controlled, the original control sequence will be
damaged once a CALL subroutine is executed in the interrupt subroutine.
Every interrupt has the capability of waking up the microcontroller when it is in SLEEP or IDLE
Mode, the wake up being generated when the interrupt request flag changes from low to high. If it is
required to prevent a certain interrupt from waking up the microcontroller then its respective request
flag should be first set high before enter SLEEP or IDLE Mode.
As only the Program Counter is pushed onto the stack, then when the interrupt is serviced, if the
contents of the accumulator, status register or other registers are altered by the interrupt service
program, their contents should be saved to the memory at the beginning of the interrupt service
routine.
To return from an interrupt subroutine, either a RET or RETI instruction may be executed. The RETI
instruction in addition to executing a return to the main program also automatically sets the EMI
bit high to allow further interrupts. The RET instruction however only executes a return to the main
program leaving the EMI bit in its present zero state and therefore disabling the execution of further
interrupts.
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Software LCD Driver
The devices have the capability of driving external LCD panels. The common pins for LCD driving,
SCOM0~SCOM5, and segment pins, SSEG0~SSEG29, are pin shared with certain pin on the I/O
ports. The LCD signals (COM and SEG) are generated using the application program.
LCD operation
An external LCD panel can be driven using this device by configuring the I/O pins as common
pins and configuring the I/O pins as segment pins. The LCD driver function is controlled using the
SLCDC0~SLCDC4 registers which in addition to controlling the overall on/off function, LCD bias
current setup function also controls the pin function selection. This enables the LCD COM and SEG
driver to generate the necessary VSS, (1/3)VDD, (2/3)VDD voltage and VDD levels for LCD 1/3 bias
operation.
The LCDEN bit in the SLCDC0 register is the overall master control for the LCD driver. The
LCD SCOMn pin is selected to be used for LCD driving by the corresponding pin-shared function
selection bits. Note that the Port Control register does not need to first setup the pins as outputs to
enable the LCD driver operation.
VDD
VDD
VDD
SCOM0
(2/3)VDD
(1/3)VDD
SCOM5
LCD
Voltage
Select
Circuit
Analog
Switch
VSS
SSEG0
SSEG29
VSS
VSS
LCD Driver structure
LCD Control Registers
The LCD COM driver enables a range of selections to be provided to suit the requirement of the
LCD panel which are being used. The bias current choice is implemented using the ISEL1 and
ISEL0 bits in the SLCDC0 register, the FRAME bit is used to select the output frame.
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SLCDC0 Register
Bit
7
6
5
4
Name
FRAME
ISEL1
ISEL0
LCDEN
3
2
1
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
COM3EN COM2EN COM1EN COM0EN
Bit 7FRAME: Output frame0 or frame1
0: Frame 0
1: Frame 1
Bit 6~5ISEL1~ISEL0: LCD bias current selection (VDD=5V)
00: 8.3μA
01: 16.7μA
10: 50μA
11: 100μA
Bit 4 LCDEN: SCOM and SSEG module on/off control
0: Off
1: On
SCOMn and SSEGm can be enable by COMnEN and SEGmEN if LCDEN=1
If LCDEN=0, SCOMn and SSEGm output VSS
When LCDEN is set, it will turn on the DC path of resistor to generate LCD Bias
voltage.
Bit 3 COM3EN: LCD or other function selection
0: Other function
1: SCOM3/SSEG3
Bit 2 COM2EN: LCD or other function selection
0: Other function
1: SCOM2/SSEG2
Bit 1 COM1EN: LCD or other function selection
0: Other function
1: SCOM1/SSEG1
Bit 0 COM0EN: LCD or other function selection
0: Other function
1: SCOM0/SSEG0
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SLCDC1 Register
Bit
Name
7
6
5
4
3
2
1
0
COM5EN COM4EN COMSEGS5 COMSEGS4 COMSEGS3 COMSEGS2 COMSEGS1 COMSEGS0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7 COM5EN: LCD or other function selection
0: Other function
1: SCOM5/SSEG5
Bit 6 COM4EN: LCD or other function selection
0: Other function
1: SCOM4/SSEG4
Bit 5 COMSEGS5: SCOM5 or SSEG 5 selection
0: SCOM5
1: SSEG5
Bit 4 COMSEGS4: SCOM4 or SSEG 4 selection
0: SCOM4
1: SSEG4
Bit 3 COMSEGS3: SCOM3 or SSEG 3 selection
0: SCOM3
1: SSEG3
Bit 2 COMSEGS2: SCOM2 or SSEG 2 selection
0: SCOM2
1: SSEG2
Bit 1 COMSEGS1: SCOM1 or SSEG 1 selection
0: SCOM1
1: SSEG1
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SLCDC2 Register
Bit
7
6
5
4
3
Name SEG13EN SEG12EN SEG11EN SEG10EN SEG9EN
2
1
0
SEG8EN
SEG7EN
SEG6EN
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7 SEG13EN: SSEG13 function control
0: Disable
1: Enable
Bit 6 SEG12EN: SSEG12 function control
0: Disable
1: Enable
Bit 5 SEG11EN: SSEG11 function control
0: Disable
1: Enable
Bit 4 SEG10EN: SSEG10 function control
0: Disable
1: Enable
Bit 3SEG9EN: SSEG9 function control
0: Disable
1: Enable
Bit 2 SEG8EN: SSEG8 function control
0: Disable
1: Enable
Bit 1 SEG7EN: SSEG7 function control
0: Disable
1: Enable
Bit 0 SEG6EN: SSEG6 function control
0: Disable
1: Enable
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SLCDC3 Register
Bit
7
6
5
4
3
2
1
0
Name SEG21EN SEG20EN SEG19EN SEG18EN SEG17EN SEG16EN SEG15EN SEG14EN
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7 SEG21EN: SSEG21 function control
0: Disable
1: Enable
Bit 6 SEG20EN: SSEG20 function control
0: Disable
1: Enable
Bit 5 SEG19EN: SSEG19 function control
0: Disable
1: Enable
Bit 4 SEG18EN: SSEG18 function control
0: Disable
1: Enable
Bit 3 SEG17EN: SSEG17 function control
0: Disable
1: Enable
Bit 2 SEG16EN: SSEG16 function control
0: Disable
1: Enable
Bit 1 SEG15EN: SSEG15 function control
0: Disable
1: Enable
Bit 0 SEG14EN: SSEG14 function control
0: Disable
1: Enable
Note: SSEG14, SSEG15 share the pins with OSC1/XT1, OSC2/XT2 functions, if select the OSC2/
OSC1 or XT2/XT1pin function, then the SEG14, SEG15 have no actions even if the functions
are enabled.
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SLCDC4 Register
Bit
7
6
5
4
3
2
1
0
Name SEG29EN SEG28EN SEG27EN SEG26EN SEG25EN SEG24EN SEG23EN SEG22EN
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7 SEG29EN: SSEG29 function control
0: Disable
1: Enable
Bit 6 SEG28EN: SSEG28 function control
0: Disable
1: Enable
Bit 5 SEG27EN: SSEG27 function control
0: Disable
1: Enable
Bit 4 SEG26EN: SSEG26 function control
0: Disable
1: Enable
Bit 3 SEG25EN: SSEG25 function control
0: Disable
1: Enable
Bit 2 SEG24EN: SSEG24 function control
0: Disable
1: Enable
Bit 1 SEG23EN: SSEG23 function control
0: Disable
1: Enable
Bit 0 SEG22EN: SSEG22 function control
0: Disable
1: Enable
LCD waveform
The accompanying waveform diagram shows a typical 1/3 Bias LCD waveform generated using the
application program. Note that the depiction of a "1" in the diagram illustrates an illuminated LCD
pixel. The COM signal polarity generated on pins SCOMn, whether 0 or 1, are generated using the
corresponding I/O data registers.
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1/3 Bias LCD Waveform
A cyclic LCD waveform includes two frames, known as Frame 0 and Frame 1 which is selected by
the FRAME bit in the SLCDC0 register. The following offers a functional explanation.
To select Frame 0 clear the FRAME bit to 0.
In frame 0, the COM signal output can have a value of VDD, or have a Vbias value of 1/3VDD (SEG_L).
The SEG signal can have a value of VSS, or have a Vbias value of 2/3VDD (SEG_H).
In frame 1, the COM signal output can have a value of VSS, or have a Vbias value of 2/3VDD (SEG_H).
The SEG signal can have a value of VDD have a Vbias value of 1/3VDD (SEG_L).
The SCOM0~SCOMn waveform is controlled by the application program using the FRAME bit,
and the corresponding I/O data register for the respective SCOM pin to determine whether the
SCOM0~SCOMn output has a value of either VDD, VSS or Vbias. The SSEG0~SSEGm waveform
is controlled in a similar way using the FRAME bit and the corresponding I/O data register for the
respective SSEG pin to determine whether the SSEG0~SSEGn output has a value of either VDD, VSS
or Vbias.
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Low Voltage Detector – LVD
Each device has a Low Voltage Detector function, also known as LVD. This enabled the device to
monitor the power supply voltage, VDD, and provide a warning signal should it fall below a certain
level. This function may be especially useful in battery applications where the supply voltage will
gradually reduce as the battery ages, as it allows an early warning battery low signal to be generated.
The Low Voltage Detector also has the capability of generating an interrupt signal.
LVD Register
The Low Voltage Detector function is controlled using a single register with the name LVDC. Three
bits in this register, VLVD2~VLVD0, are used to select one of eight fixed voltages below which
a low voltage condition will be determined. A low voltage condition is indicated when the LVDO
bit is set. If the LVDO bit is low, this indicates that the VDD voltage is above the preset low voltage
value. The LVDEN bit is used to control the overall on/off function of the low voltage detector.
Setting the bit high will enable the low voltage detector. Clearing the bit to zero will switch off the
internal low voltage detector circuits. As the low voltage detector will consume a certain amount of
power, it may be desirable to switch off the circuit when not in use, an important consideration in
power sensitive battery powered applications.
LVDC Register
Bit
7
6
5
4
Name
—
—
LVDO
R/W
—
—
R
POR
—
—
0
Bit 7~6
3
2
1
0
LVDEN
—
VLVD2
VLVD1
VLVD0
R/W
—
R/W
R/W
R/W
0
—
0
0
0
Unimplemented, read as "0"
Bit 5LVDO: LVD Output Flag
0: No Low Voltage Detect
1: Low Voltage Detect
Bit 4LVDEN: Low Voltage Detector Control
0: Disable
1: Enable
Bit 3
Unimplemented, read as “0”
Bit 2~0VLVD2~VLVD0: Select LVD Voltage
000: 2.0V
001: 2.2V
010: 2.4V
011: 2.7V
100: 3.0V
101: 3.3V
110: 3.6V
111: 4.0V
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LVD Operation
The Low Voltage Detector function operates by comparing the power supply voltage, VDD, with a
pre-specified voltage level stored in the LVDC register. This has a range of between 2.0V and 4.0V.
When the power supply voltage, VDD, falls below this pre-determined value, the LVDO bit will be
set high indicating a low power supply voltage condition. The Low Voltage Detector function is
supplied by a reference voltage which will be automatically enabled. When the device is powered
down the low voltage detector will remain active if the LVDEN bit is high. After enabling the Low
Voltage Detector, a time delay tLVDS should be allowed for the circuitry to stabilise before reading the
LVDO bit. Note also that as the VDD voltage may rise and fall rather slowly, at the voltage nears that
of VLVD, there may be multiple bit LVDO transitions.
LVD Operation
The Low Voltage Detector also has its own interrupt which is contained within one of the Multifunction interrupts, providing an alternative means of low voltage detection, in addition to polling
the LVDO bit. The interrupt will only be generated after a delay of tLVD after the LVDO bit has been
set high by a low voltage condition. When the device is powered down the Low Voltage Detector
will remain active if the LVDEN bit is high. In this case, the LVF interrupt request flag will be set,
causing an interrupt to be generated if VDD falls below the preset LVD voltage. This will cause the
device to wake-up from the SLEEP Mode, however if the Low Voltage Detector wake up function is
not required then the LVF flag should be first set high before the device enters the SLEEP Mode.
When LVD function is enabled, it is recommenced to clear LVD flag first, and then enables interrupt
function to avoid mistake action.
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Configuration Option
Configuration options refer to certain options within the MCU that are programmed into the device
during the programming process. During the development process, these options are selected using
the HT-IDE software development tools. As these options are programmed into the device using
the hardware programming tools, once they are selected they cannot be changed later using the
application program. All options must be defined for proper system function, the details of which are
shown in the table.
No.
Options
Oscillator Option
1
High Speed/Low Speed System Oscillator Selection – fOSC:
HIRC+LIRC
HIRC+LXT
HXT+LIRC
Application Circuit
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Instruction Set
Introduction
Central to the successful operation of any microcontroller is its instruction set, which is a set of
program instruction codes that directs the microcontroller to perform certain operations. In the case
of Holtek microcontroller, a comprehensive and flexible set of over 60 instructions is provided to
enable programmers to implement their application with the minimum of programming overheads.
For easier understanding of the various instruction codes, they have been subdivided into several
functional groupings.
Instruction Timing
Most instructions are implemented within one instruction cycle. The exceptions to this are branch,
call, or table read instructions where two instruction cycles are required. One instruction cycle is
equal to 4 system clock cycles, therefore in the case of an 8MHz system oscillator, most instructions
would be implemented within 0.5μs and branch or call instructions would be implemented within
1μs. Although instructions which require one more cycle to implement are generally limited to
the JMP, CALL, RET, RETI and table read instructions, it is important to realize that any other
instructions which involve manipulation of the Program Counter Low register or PCL will also take
one more cycle to implement. As instructions which change the contents of the PCL will imply a
direct jump to that new address, one more cycle will be required. Examples of such instructions
would be “CLR PCL” or “MOV PCL, A”. For the case of skip instructions, it must be noted that if
the result of the comparison involves a skip operation then this will also take one more cycle, if no
skip is involved then only one cycle is required.
Moving and Transferring Data
The transfer of data within the microcontroller program is one of the most frequently used
operations. Making use of several kinds of MOV instructions, data can be transferred from registers
to the Accumulator and vice-versa as well as being able to move specific immediate data directly
into the Accumulator. One of the most important data transfer applications is to receive data from
the input ports and transfer data to the output ports.
Arithmetic Operations
The ability to perform certain arithmetic operations and data manipulation is a necessary feature of
most microcontroller applications. Within the Holtek microcontroller instruction set are a range of
add and subtract instruction mnemonics to enable the necessary arithmetic to be carried out. Care
must be taken to ensure correct handling of carry and borrow data when results exceed 255 for
addition and less than 0 for subtraction. The increment and decrement instructions such as INC,
INCA, DEC and DECA provide a simple means of increasing or decreasing by a value of one of the
values in the destination specified.
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Logical and Rotate Operation
The standard logical operations such as AND, OR, XOR and CPL all have their own instruction
within the Holtek microcontroller instruction set. As with the case of most instructions involving
data manipulation, data must pass through the Accumulator which may involve additional
programming steps. In all logical data operations, the zero flag may be set if the result of the
operation is zero. Another form of logical data manipulation comes from the rotate instructions such
as RR, RL, RRC and RLC which provide a simple means of rotating one bit right or left. Different
rotate instructions exist depending on program requirements. Rotate instructions are useful for serial
port programming applications where data can be rotated from an internal register into the Carry
bit from where it can be examined and the necessary serial bit set high or low. Another application
which rotate data operations are used is to implement multiplication and division calculations.
Branches and Control Transfer
Program branching takes the form of either jumps to specified locations using the JMP instruction
or to a subroutine using the CALL instruction. They differ in the sense that in the case of a
subroutine call, the program must return to the instruction immediately when the subroutine has
been carried out. This is done by placing a return instruction “RET” in the subroutine which will
cause the program to jump back to the address right after the CALL instruction. In the case of a JMP
instruction, the program simply jumps to the desired location. There is no requirement to jump back
to the original jumping off point as in the case of the CALL instruction. One special and extremely
useful set of branch instructions are the conditional branches. Here a decision is first made regarding
the condition of a certain data memory or individual bits. Depending upon the conditions, the
program will continue with the next instruction or skip over it and jump to the following instruction.
These instructions are the key to decision making and branching within the program perhaps
determined by the condition of certain input switches or by the condition of internal data bits.
Bit Operations
The ability to provide single bit operations on Data Memory is an extremely flexible feature of all
Holtek microcontrollers. This feature is especially useful for output port bit programming where
individual bits or port pins can be directly set high or low using either the “SET [m].i” or “CLR [m].i”
instructions respectively. The feature removes the need for programmers to first read the 8-bit output
port, manipulate the input data to ensure that other bits are not changed and then output the port with
the correct new data. This read-modify-write process is taken care of automatically when these bit
operation instructions are used.
Table Read Operations
Data storage is normally implemented by using registers. However, when working with large
amounts of fixed data, the volume involved often makes it inconvenient to store the fixed data in
the Data Memory. To overcome this problem, Holtek microcontrollers allow an area of Program
Memory to be setup as a table where data can be directly stored. A set of easy to use instructions
provides the means by which this fixed data can be referenced and retrieved from the Program
Memory.
Other Operations
In addition to the above functional instructions, a range of other instructions also exist such as
the “HALT” instruction for Power-down operations and instructions to control the operation of
the Watchdog Timer for reliable program operations under extreme electric or electromagnetic
environments. For their relevant operations, refer to the functional related sections.
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Instruction Set Summary
The instructions related to the data memory access in the following table can be used when the
desired data memory is located in Data Memory sector 0.
Table Conventions
x: Bits immediate data
m: Data Memory address
A: Accumulator
i: 0~7 number of bits
addr: Program memory address
Mnemonic
Description
Cycles
Flag Affected
Add Data Memory to ACC
Add ACC to Data Memory
Add immediate data to ACC
Add Data Memory to ACC with Carry
Add ACC to Data memory with Carry
Subtract immediate data from the ACC
Subtract Data Memory from ACC
Subtract Data Memory from ACC with result in Data Memory
Subtract immediate data from ACC with Carry
Subtract Data Memory from ACC with Carry
Subtract Data Memory from ACC with Carry, result in Data Memory
Decimal adjust ACC for Addition with result in Data Memory
1
1Note
1
1
1Note
1
1
1Note
1
1
1Note
1Note
Z, C, AC, OV, SC
Z, C, AC, OV, SC
Z, C, AC, OV, SC
Z, C, AC, OV, SC
Z, C, AC, OV, SC
Z, C, AC, OV, SC, CZ
Z, C, AC, OV, SC, CZ
Z, C, AC, OV, SC, CZ
Z, C, AC, OV, SC, CZ
Z, C, AC, OV, SC, CZ
Z, C, AC, OV, SC, CZ
C
1
1
1
1Note
1Note
1Note
1
1
1
1Note
1
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Increment Data Memory with result in ACC
Increment Data Memory
Decrement Data Memory with result in ACC
Decrement Data Memory
1
1Note
1
1Note
Z
Z
Z
Z
Rotate Data Memory right with result in ACC
Rotate Data Memory right
Rotate Data Memory right through Carry with result in ACC
Rotate Data Memory right through Carry
Rotate Data Memory left with result in ACC
Rotate Data Memory left
Rotate Data Memory left through Carry with result in ACC
Rotate Data Memory left through Carry
1
1Note
1
1Note
1
1Note
1
1Note
None
None
C
C
None
None
C
C
Arithmetic
ADD A,[m]
ADDM A,[m]
ADD A,x
ADC A,[m]
ADCM A,[m]
SUB A,x
SUB A,[m]
SUBM A,[m]
SBC A,x
SBC A,[m]
SBCM A,[m]
DAA [m]
Logic Operation
AND A,[m]
OR A,[m]
XOR A,[m]
ANDM A,[m]
ORM A,[m]
XORM A,[m]
AND A,x
OR A,x
XOR A,x
CPL [m]
CPLA [m]
Logical AND Data Memory to ACC
Logical OR Data Memory to ACC
Logical XOR Data Memory to ACC
Logical AND ACC to Data Memory
Logical OR ACC to Data Memory
Logical XOR ACC to Data Memory
Logical AND immediate Data to ACC
Logical OR immediate Data to ACC
Logical XOR immediate Data to ACC
Complement Data Memory
Complement Data Memory with result in ACC
Increment & Decrement
INCA [m]
INC [m]
DECA [m]
DEC [m]
Rotate
RRA [m]
RR [m]
RRCA [m]
RRC [m]
RLA [m]
RL [m]
RLCA [m]
RLC [m]
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Mnemonic
Description
Cycles Flag Affected
Data Move
MOV A,[m]
MOV [m],A
MOV A,x
Move Data Memory to ACC
Move ACC to Data Memory
Move immediate data to ACC
1
1Note
1
None
None
None
Clear bit of Data Memory
Set bit of Data Memory
1Note
1Note
None
None
2
1Note
1Note
1Note
1Note
1Note
1Note
1Note
1Note
1Note
2
2
2
2
None
None
None
None
None
None
None
None
None
None
None
None
None
None
2Note
2Note
2Note
None
None
None
2Note
None
1
1Note
1Note
1
1Note
1
1
None
None
None
TO, PDF
None
None
TO, PDF
Bit Operation
CLR [m].i
SET [m].i
Branch Operation
JMP addr
SZ [m]
SZA [m]
SZ [m].i
SNZ [m]
SNZ [m].i
SIZ [m]
SDZ [m]
SIZA [m]
SDZA [m]
CALL addr
RET
RET A,x
RETI
Jump unconditionally
Skip if Data Memory is zero
Skip if Data Memory is zero with data movement to ACC
Skip if bit i of Data Memory is zero
Skip if Data Memory is not zero
Skip if bit i of Data Memory is not zero
Skip if increment Data Memory is zero
Skip if decrement Data Memory is zero
Skip if increment Data Memory is zero with result in ACC
Skip if decrement Data Memory is zero with result in ACC
Subroutine call
Return from subroutine
Return from subroutine and load immediate data to ACC
Return from interrupt
Table Read Operation
TABRD [m] Read table to TBLH and Data Memory
TABRDL [m] Read table (last page) to TBLH and Data Memory
ITABRD [m] Increment table pointer TBLP first and Read table to TBLH and Data Memory
Increment table pointer TBLP first and Read table (last page) to TBLH and
ITABRDL [m]
Data Memory
Miscellaneous
NOP
CLR [m]
SET [m]
CLR WDT
SWAP [m]
SWAPA [m]
HALT
No operation
Clear Data Memory
Set Data Memory
Clear Watchdog Timer
Swap nibbles of Data Memory
Swap nibbles of Data Memory with result in ACC
Enter power down mode
Note: 1. For skip instructions, if the result of the comparison involves a skip then up to three cycles are required, if
no skip takes place only one cycle is required.
2. Any instruction which changes the contents of the PCL will also require 2 cycles for execution.
3. For the “CLR WDT” instruction the TO and PDF flags may be affected by the execution status. The TO
and PDF flags are cleared after the “CLR WDT” instructions is executed. Otherwise the TO and PDF
flags remain unchanged.
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Extended Instruction Set
The extended instructions are used to support the full range address access for the data memory.
When the accessed data memory is located in any data memory sections except sector 0, the
extended instruction can be used to access the data memory instead of using the indirect addressing
access to improve the CPU firmware performance.
Mnemonic
Description
Cycles
Flag Affected
Add Data Memory to ACC
Add ACC to Data Memory
Add Data Memory to ACC with Carry
Add ACC to Data memory with Carry
Subtract Data Memory from ACC
Subtract Data Memory from ACC with result in Data Memory
Subtract Data Memory from ACC with Carry
Subtract Data Memory from ACC with Carry, result in Data Memory
Decimal adjust ACC for Addition with result in Data Memory
2
2Note
2
2Note
2
2Note
2
2Note
2Note
Z, C, AC, OV, SC
Z, C, AC, OV, SC
Z, C, AC, OV, SC
Z, C, AC, OV, SC
Z, C, AC, OV, SC, CZ
Z, C, AC, OV, SC, CZ
Z, C, AC, OV, SC, CZ
Z, C, AC, OV, SC, CZ
C
2
2
2
2Note
2Note
2Note
2Note
2
Z
Z
Z
Z
Z
Z
Z
Z
Increment Data Memory with result in ACC
Increment Data Memory
Decrement Data Memory with result in ACC
Decrement Data Memory
2
2Note
2
2Note
Z
Z
Z
Z
Rotate Data Memory right with result in ACC
Rotate Data Memory right
Rotate Data Memory right through Carry with result in ACC
Rotate Data Memory right through Carry
Rotate Data Memory left with result in ACC
Rotate Data Memory left
Rotate Data Memory left through Carry with result in ACC
Rotate Data Memory left through Carry
2
2Note
2
2Note
2
2Note
2
2Note
None
None
C
C
None
None
C
C
Move Data Memory to ACC
Move ACC to Data Memory
2
2Note
None
None
Clear bit of Data Memory
Set bit of Data Memory
2Note
2Note
None
None
Arithmetic
LADD A,[m]
LADDM A,[m]
LADC A,[m]
LADCM A,[m]
LSUB A,[m]
LSUBM A,[m]
LSBC A,[m]
LSBCM A,[m]
LDAA [m]
Logic Operation
LAND A,[m]
LOR A,[m]
LXOR A,[m]
LANDM A,[m]
LORM A,[m]
LXORM A,[m]
LCPL [m]
LCPLA [m]
Logical AND Data Memory to ACC
Logical OR Data Memory to ACC
Logical XOR Data Memory to ACC
Logical AND ACC to Data Memory
Logical OR ACC to Data Memory
Logical XOR ACC to Data Memory
Complement Data Memory
Complement Data Memory with result in ACC
Increment & Decrement
LINCA [m]
LINC [m]
LDECA [m]
LDEC [m]
Rotate
LRRA [m]
LRR [m]
LRRCA [m]
LRRC [m]
LRLA [m]
LRL [m]
LRLCA [m]
LRLC [m]
Data Move
LMOV A,[m]
LMOV [m],A
Bit Operation
LCLR [m].i
LSET [m].i
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Mnemonic
Description
Cycles Flag Affected
Branch
LSZ [m]
LSZA [m]
LSNZ [m]
LSZ [m].i
LSNZ [m].i
LSIZ [m]
LSDZ [m]
LSIZA [m]
LSDZA [m]
Skip if Data Memory is zero
Skip if Data Memory is zero with data movement to ACC
Skip if Data Memory is not zero
Skip if bit i of Data Memory is zero
Skip if bit i of Data Memory is not zero
Skip if increment Data Memory is zero
Skip if decrement Data Memory is zero
Skip if increment Data Memory is zero with result in ACC
Skip if decrement Data Memory is zero with result in ACC
2Note
2Note
2Note
2Note
2Note
2Note
2Note
2Note
2Note
None
None
None
None
None
None
None
None
None
3Note
3Note
3Note
None
None
None
3Note
None
2Note
2Note
2Note
2
None
None
None
None
Table Read
LTABRD [m] Read table to TBLH and Data Memory
LTABRDL [m] Read table (last page) to TBLH and Data Memory
LITABRD [m] Increment table pointer TBLP first and Read table to TBLH and Data Memory
Increment table pointer TBLP first and Read table (last page) to TBLH and
LITABRDL [m]
Data Memory
Miscellaneous
LCLR [m]
LSET [m]
LSWAP [m]
LSWAPA [m]
Clear Data Memory
Set Data Memory
Swap nibbles of Data Memory
Swap nibbles of Data Memory with result in ACC
Note: 1. For these extended skip instructions, if the result of the comparison involves a skip then up to four cycles
are required, if no skip takes place two cycles is required.
2. Any extended instruction which changes the contents of the PCL register will also require three cycles for
execution.
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Instruction Definition
ADC A,[m]
Description
Operation
Affected flag(s)
Add Data Memory to ACC with Carry
The contents of the specified Data Memory, Accumulator and the carry flag are added.
The result is stored in the Accumulator.
ACC ← ACC + [m] + C
OV, Z, AC, C, SC
ADCM A,[m]
Description
Operation
Affected flag(s)
Add ACC to Data Memory with Carry
The contents of the specified Data Memory, Accumulator and the carry flag are added. The result is stored in the specified Data Memory.
[m] ← ACC + [m] + C
OV, Z, AC, C, SC
Add Data Memory to ACC
ADD A,[m]
Description
The contents of the specified Data Memory and the Accumulator are added.
The result is stored in the Accumulator.
Operation
Affected flag(s)
ACC ← ACC + [m]
OV, Z, AC, C, SC
ADD A,x
Description
Operation
Affected flag(s)
Add immediate data to ACC
The contents of the Accumulator and the specified immediate data are added. The result is stored in the Accumulator.
ACC ← ACC + x
OV, Z, AC, C, SC
ADDM A,[m]
Description
Operation
Affected flag(s)
Add ACC to Data Memory
The contents of the specified Data Memory and the Accumulator are added. The result is stored in the specified Data Memory.
[m] ← ACC + [m]
OV, Z, AC, C, SC
AND A,[m]
Description
Operation
Affected flag(s)
Logical AND Data Memory to ACC
Data in the Accumulator and the specified Data Memory perform a bitwise logical AND operation. The result is stored in the Accumulator.
ACC ← ACC ″AND″ [m]
Z
AND A,x
Description
Operation
Affected flag(s)
Logical AND immediate data to ACC
Data in the Accumulator and the specified immediate data perform a bit wise logical AND operation. The result is stored in the Accumulator.
ACC ← ACC ″AND″ x
Z
ANDM A,[m]
Description
Operation
Affected flag(s)
Logical AND ACC to Data Memory
Data in the specified Data Memory and the Accumulator perform a bitwise logical AND
operation. The result is stored in the Data Memory.
[m] ← ACC ″AND″ [m]
Z
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CALL addr
Description
Operation
Affected flag(s)
Subroutine call
Unconditionally calls a subroutine at the specified address. The Program Counter then
increments by 1 to obtain the address of the next instruction which is then pushed onto the
stack. The specified address is then loaded and the program continues execution from this
new address. As this instruction requires an additional operation, it is a two cycle instruction.
Stack ← Program Counter + 1
Program Counter ← addr
None
CLR [m]
Description
Operation
Affected flag(s)
Clear Data Memory
Each bit of the specified Data Memory is cleared to 0.
[m] ← 00H
None
CLR [m].i
Description
Operation
Affected flag(s)
Clear bit of Data Memory
Bit i of the specified Data Memory is cleared to 0.
[m].i ← 0
None
CLR WDT
Description
Operation
Affected flag(s)
Clear Watchdog Timer
The TO, PDF flags and the WDT are all cleared.
WDT cleared
TO ← 0
PDF ← 0
TO, PDF
CPL [m]
Description
Operation
Affected flag(s)
Complement Data Memory
Each bit of the specified Data Memory is logically complemented (1′s complement). Bits which
previously contained a 1 are changed to 0 and vice versa.
[m] ← [m]
Z
CPLA [m]
Description
Operation
Affected flag(s)
Complement Data Memory with result in ACC
Each bit of the specified Data Memory is logically complemented (1′s complement). Bits which
previously contained a 1 are changed to 0 and vice versa. The complemented result is stored in
the Accumulator and the contents of the Data Memory remain unchanged.
ACC ← [m]
Z
DAA [m]
Description
Operation
Affected flag(s)
Decimal-Adjust ACC for addition with result in Data Memory
Convert the contents of the Accumulator value to a BCD (Binary Coded Decimal) value
resulting from the previous addition of two BCD variables. If the low nibble is greater than 9
or if AC flag is set, then a value of 6 will be added to the low nibble. Otherwise the low nibble
remains unchanged. If the high nibble is greater than 9 or if the C flag is set, then a value of 6
will be added to the high nibble. Essentially, the decimal conversion is performed by adding
00H, 06H, 60H or 66H depending on the Accumulator and flag conditions. Only the C flag
may be affected by this instruction which indicates that if the original BCD sum is greater than
100, it allows multiple precision decimal addition.
[m] ← ACC + 00H or
[m] ← ACC + 06H or [m] ← ACC + 60H or
[m] ← ACC + 66H
C
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DEC [m]
Description
Operation
Affected flag(s)
Decrement Data Memory
Data in the specified Data Memory is decremented by 1.
[m] ← [m] − 1
Z
DECA [m]
Description
Operation
Affected flag(s)
Decrement Data Memory with result in ACC
Data in the specified Data Memory is decremented by 1. The result is stored in the
Accumulator. The contents of the Data Memory remain unchanged.
ACC ← [m] − 1
Z
HALT
Description
Operation
Affected flag(s)
Enter power down mode
This instruction stops the program execution and turns off the system clock. The contents of the Data Memory and registers are retained. The WDT and prescaler are cleared. The power
down flag PDF is set and the WDT time-out flag TO is cleared.
TO ← 0
PDF ← 1
TO, PDF
INC [m]
Description
Operation
Affected flag(s)
Increment Data Memory
Data in the specified Data Memory is incremented by 1.
[m] ← [m] + 1
Z
INCA [m]
Description
Operation
Affected flag(s)
Increment Data Memory with result in ACC
Data in the specified Data Memory is incremented by 1. The result is stored in the Accumulator.
The contents of the Data Memory remain unchanged.
ACC ← [m] + 1
Z
JMP addr
Description
Operation
Affected flag(s)
Jump unconditionally
The contents of the Program Counter are replaced with the specified address. Program
execution then continues from this new address. As this requires the insertion of a dummy
instruction while the new address is loaded, it is a two cycle instruction.
Program Counter ← addr
None
MOV A,[m]
Description
Operation
Affected flag(s)
Move Data Memory to ACC
The contents of the specified Data Memory are copied to the Accumulator.
ACC ← [m]
None
MOV A,x
Description
Operation
Affected flag(s)
Move immediate data to ACC
The immediate data specified is loaded into the Accumulator.
ACC ← x
None
MOV [m],A
Description
Operation
Affected flag(s)
Move ACC to Data Memory
The contents of the Accumulator are copied to the specified Data Memory.
[m] ← ACC
None
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NOP
Description
Operation
Affected flag(s)
No operation
No operation is performed. Execution continues with the next instruction.
No operation
None
OR A,[m]
Description
Operation
Affected flag(s)
Logical OR Data Memory to ACC
Data in the Accumulator and the specified Data Memory perform a bitwise
logical OR operation. The result is stored in the Accumulator.
ACC ← ACC ″OR″ [m]
Z
OR A,x
Description
Operation
Affected flag(s)
Logical OR immediate data to ACC
Data in the Accumulator and the specified immediate data perform a bitwise logical OR operation. The result is stored in the Accumulator.
ACC ← ACC ″OR″ x
Z
ORM A,[m]
Description
Operation
Affected flag(s)
Logical OR ACC to Data Memory
Data in the specified Data Memory and the Accumulator perform a bitwise logical OR operation. The result is stored in the Data Memory.
[m] ← ACC ″OR″ [m]
Z
RET
Description
Operation
Affected flag(s)
Return from subroutine
The Program Counter is restored from the stack. Program execution continues at the restored
address.
Program Counter ← Stack
None
RET A,x
Description
Operation
Affected flag(s)
Return from subroutine and load immediate data to ACC
The Program Counter is restored from the stack and the Accumulator loaded with the specified immediate data. Program execution continues at the restored address.
Program Counter ← Stack
ACC ← x
None
RETI
Description
Operation
Affected flag(s)
Return from interrupt
The Program Counter is restored from the stack and the interrupts are re-enabled by setting the
EMI bit. EMI is the master interrupt global enable bit. If an interrupt was pending when the RETI instruction is executed, the pending Interrupt routine will be processed before returning to the main program.
Program Counter ← Stack
EMI ← 1
None
RL [m]
Description
Operation
Affected flag(s)
Rotate Data Memory left
The contents of the specified Data Memory are rotated left by 1 bit with bit 7 rotated into bit 0.
[m].(i+1) ← [m].i; (i=0~6)
[m].0 ← [m].7
None
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RLA [m]
Description
Operation
Affected flag(s)
Rotate Data Memory left with result in ACC
The contents of the specified Data Memory are rotated left by 1 bit with bit 7 rotated into bit 0.
The rotated result is stored in the Accumulator and the contents of the Data Memory remain
unchanged.
ACC.(i+1) ← [m].i; (i=0~6)
ACC.0 ← [m].7
None
RLC [m]
Description
Operation
Affected flag(s)
Rotate Data Memory left through Carry
The contents of the specified Data Memory and the carry flag are rotated left by 1 bit. Bit 7
replaces the Carry bit and the original carry flag is rotated into bit 0.
[m].(i+1) ← [m].i; (i=0~6)
[m].0 ← C
C ← [m].7
C
RLCA [m]
Description
Operation
Affected flag(s)
Rotate Data Memory left through Carry with result in ACC
Data in the specified Data Memory and the carry flag are rotated left by 1 bit. Bit 7 replaces the
Carry bit and the original carry flag is rotated into the bit 0. The rotated result is stored in the
Accumulator and the contents of the Data Memory remain unchanged.
ACC.(i+1) ← [m].i; (i=0~6)
ACC.0 ← C
C ← [m].7
C
RR [m]
Description
Operation
Affected flag(s)
Rotate Data Memory right
The contents of the specified Data Memory are rotated right by 1 bit with bit 0 rotated into bit 7.
[m].i ← [m].(i+1); (i=0~6)
[m].7 ← [m].0
None
RRA [m]
Description
Operation
Affected flag(s)
Rotate Data Memory right with result in ACC
Data in the specified Data Memory and the carry flag are rotated right by 1 bit with bit 0
rotated into bit 7. The rotated result is stored in the Accumulator and the contents of the
Data Memory remain unchanged.
ACC.i ← [m].(i+1); (i=0~6)
ACC.7 ← [m].0
None
RRC [m]
Description
Operation
Affected flag(s)
Rotate Data Memory right through Carry
The contents of the specified Data Memory and the carry flag are rotated right by 1 bit. Bit 0
replaces the Carry bit and the original carry flag is rotated into bit 7.
[m].i ← [m].(i+1); (i=0~6)
[m].7 ← C
C ← [m].0
C
Rev. 1.00
180
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
RRCA [m]
Description
Operation
Affected flag(s)
Rotate Data Memory right through Carry with result in ACC
Data in the specified Data Memory and the carry flag are rotated right by 1 bit. Bit 0 replaces the Carry bit and the original carry flag is rotated into bit 7. The rotated result is stored in the Accumulator and the contents of the Data Memory remain unchanged.
ACC.i ← [m].(i+1); (i=0~6)
ACC.7 ← C
C ← [m].0
C
SBC A,[m]
Description
Operation
Affected flag(s)
Subtract Data Memory from ACC with Carry
The contents of the specified Data Memory and the complement of the carry flag are
subtracted from the Accumulator. The result is stored in the Accumulator. Note that if the result of subtraction is negative, the C flag will be cleared to 0, otherwise if the result is
positive or zero, the C flag will be set to 1.
ACC ← ACC − [m] − C
OV, Z, AC, C, SC, CZ
SBC A, x
Description
Operation
Affected flag(s)
Subtract immediate data from ACC with Carry
The immediate data and the complement of the carry flag are subtracted from the Accumulator. The result is stored in the Accumulator. Note that if the result of subtraction is negative, the C flag will be cleared to 0, otherwise if the result is positive or zero, the C flag will be set to 1.
ACC ← ACC - [m] - C
OV, Z, AC, C, SC, CZ
SBCM A,[m]
Description
Operation
Affected flag(s)
Subtract Data Memory from ACC with Carry and result in Data Memory
The contents of the specified Data Memory and the complement of the carry flag are subtracted from the Accumulator. The result is stored in the Data Memory. Note that if the result of subtraction is negative, the C flag will be cleared to 0, otherwise if the result is positive or zero, the C flag will be set to 1.
[m] ← ACC − [m] − C
OV, Z, AC, C, SC, CZ
SDZ [m]
Description
Operation
Affected flag(s)
Skip if decrement Data Memory is 0
The contents of the specified Data Memory are first decremented by 1. If the result is 0 the following instruction is skipped. As this requires the insertion of a dummy instruction while the next instruction is fetched, it is a two cycle instruction. If the result is not 0 the program proceeds with the following instruction.
[m] ← [m] − 1
Skip if [m]=0
None
SDZA [m]
Description
Operation
Affected flag(s)
Skip if decrement Data Memory is zero with result in ACC
The contents of the specified Data Memory are first decremented by 1. If the result is 0, the following instruction is skipped. The result is stored in the Accumulator but the specified Data Memory contents remain unchanged. As this requires the insertion of a dummy
instruction while the next instruction is fetched, it is a two cycle instruction. If the result is not 0,
the program proceeds with the following instruction.
ACC ← [m] − 1
Skip if ACC=0
None
Rev. 1.00
181
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
SET [m]
Description
Operation
Affected flag(s)
Set Data Memory
Each bit of the specified Data Memory is set to 1.
[m] ← FFH
None
SET [m].i
Description
Operation
Affected flag(s)
Set bit of Data Memory
Bit i of the specified Data Memory is set to 1.
[m].i ← 1
None
SIZ [m]
Description
Operation
Affected flag(s)
Skip if increment Data Memory is 0
The contents of the specified Data Memory are first incremented by 1. If the result is 0, the
following instruction is skipped. As this requires the insertion of a dummy instruction while the next instruction is fetched, it is a two cycle instruction. If the result is not 0 the program
proceeds with the following instruction.
[m] ← [m] + 1
Skip if [m]=0
None
SIZA [m]
Description
Operation
Affected flag(s)
Skip if increment Data Memory is zero with result in ACC
The contents of the specified Data Memory are first incremented by 1. If the result is 0, the following instruction is skipped. The result is stored in the Accumulator but the specified
Data Memory contents remain unchanged. As this requires the insertion of a dummy
instruction while the next instruction is fetched, it is a two cycle instruction. If the result is not
0 the program proceeds with the following instruction.
ACC ← [m] + 1
Skip if ACC=0
None
SNZ [m].i
Description
Operation
Affected flag(s)
Skip if Data Memory is not 0
If the specified Data Memory is not 0, the following instruction is skipped. As this requires the
insertion of a dummy instruction while the next instruction is fetched, it is a two cycle instruction. If the result is 0 the program proceeds with the following instruction.
Skip if [m].i ≠ 0
None
SNZ [m]
Description
Operation
Affected flag(s)
Skip if Data Memory is not 0
If the specified Data Memory is not 0, the following instruction is skipped. As this requires the
insertion of a dummy instruction while the next instruction is fetched, it is a two cycle instruction. If the result is 0 the program proceeds with the following instruction.
Skip if [m]≠ 0
None
SUB A,[m]
Description
Operation
Affected flag(s)
Subtract Data Memory from ACC
The specified Data Memory is subtracted from the contents of the Accumulator. The result is stored in the Accumulator. Note that if the result of subtraction is negative, the C flag will be cleared to 0, otherwise if the result is positive or zero, the C flag will be set to 1.
ACC ← ACC − [m]
OV, Z, AC, C, SC, CZ
Rev. 1.00
182
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
SUBM A,[m]
Description
Operation
Affected flag(s)
Subtract Data Memory from ACC with result in Data Memory
The specified Data Memory is subtracted from the contents of the Accumulator. The result is stored in the Data Memory. Note that if the result of subtraction is negative, the C flag will be cleared to 0, otherwise if the result is positive or zero, the C flag will be set to 1.
[m] ← ACC − [m]
OV, Z, AC, C, SC, CZ
SUB A,x
Description
Operation
Affected flag(s)
Subtract immediate data from ACC
The immediate data specified by the code is subtracted from the contents of the Accumulator. The result is stored in the Accumulator. Note that if the result of subtraction is negative, the C flag will be cleared to 0, otherwise if the result is positive or zero, the C flag will be set to 1.
ACC ← ACC − x
OV, Z, AC, C, SC, CZ
SWAP [m]
Description
Operation
Affected flag(s)
Swap nibbles of Data Memory
The low-order and high-order nibbles of the specified Data Memory are interchanged.
[m].3~[m].0 ↔ [m].7~[m].4
None
SWAPA [m]
Description
Operation
Affected flag(s)
Swap nibbles of Data Memory with result in ACC
The low-order and high-order nibbles of the specified Data Memory are interchanged. The result is stored in the Accumulator. The contents of the Data Memory remain unchanged.
ACC.3~ACC.0 ← [m].7~[m].4
ACC.7~ACC.4 ← [m].3~[m].0
None
SZ [m]
Description
Operation
Affected flag(s)
Skip if Data Memory is 0
If the contents of the specified Data Memory is 0, the following instruction is skipped. As this requires the insertion of a dummy instruction while the next instruction is fetched, it is a two cycle instruction. If the result is not 0 the program proceeds with the following instruction.
Skip if [m]=0
None
SZA [m]
Description
Operation
Affected flag(s)
Skip if Data Memory is 0 with data movement to ACC
The contents of the specified Data Memory are copied to the Accumulator. If the value is zero, the following instruction is skipped. As this requires the insertion of a dummy instruction while the next instruction is fetched, it is a two cycle instruction. If the result is not 0 the program proceeds with the following instruction.
ACC ← [m]
Skip if [m]=0
None
SZ [m].i
Description
Operation
Affected flag(s)
Skip if bit i of Data Memory is 0
If bit i of the specified Data Memory is 0, the following instruction is skipped. As this requires
the insertion of a dummy instruction while the next instruction is fetched, it is a two cycle
instruction. If the result is not 0, the program proceeds with the following instruction.
Skip if [m].i=0
None
Rev. 1.00
183
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
TABRD [m]
Description
Operation
Affected flag(s)
Read table (current page) to TBLH and Data Memory
The low byte of the program code (current page) addressed by the table pointer (TBLP) is moved to the specified Data Memory and the high byte moved to TBLH.
[m] ← program code (low byte)
TBLH ← program code (high byte)
None
TABRDL [m]
Description
Operation
Affected flag(s)
Read table (last page) to TBLH and Data Memory
The low byte of the program code (last page) addressed by the table pointer (TBLP) is moved to the specified Data Memory and the high byte moved to TBLH.
[m] ← program code (low byte)
TBLH ← program code (high byte)
None
ITABRD [m]
Description
Operation
Affected flag(s)
Increment table pointer low byte first and read table to TBLH and Data Memory
Increment table pointer low byte, TBLP, first and then the program code addressed by the table pointer (TBHP and TBLP) is moved to the specified Data Memory and the high byte moved to TBLH.
[m] ← program code (low byte)
TBLH ← program code (high byte)
None
ITABRDL [m]
Description
Operation
Affected flag(s)
Increment table pointer low byte first and read table (last page) to TBLH and Data Memory
Increment table pointer low byte, TBLP, first and then the low byte of the program code (last page) addressed by the table pointer (TBLP) is moved to the specified Data Memory and the high byte moved to TBLH.
[m] ← program code (low byte)
TBLH ← program code (high byte)
None
XOR A,[m]
Description
Operation
Affected flag(s)
Logical XOR Data Memory to ACC
Data in the Accumulator and the specified Data Memory perform a bitwise logical XOR operation. The result is stored in the Accumulator.
ACC ← ACC ″XOR″ [m]
Z
XORM A,[m]
Description
Operation
Affected flag(s)
Logical XOR ACC to Data Memory
Data in the specified Data Memory and the Accumulator perform a bitwise logical XOR operation. The result is stored in the Data Memory.
[m] ← ACC ″XOR″ [m]
Z
XOR A,x
Description
Operation
Affected flag(s)
Logical XOR immediate data to ACC
Data in the Accumulator and the specified immediate data perform a bitwise logical XOR operation. The result is stored in the Accumulator.
ACC ← ACC ″XOR″ x
Z
Rev. 1.00
184
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Extended Instruction Definition
The extended instructions are used to directly access the data stored in any data memory sections.
LADC A,[m]
Description
Operation
Affected flag(s)
Add Data Memory to ACC with Carry
The contents of the specified Data Memory, Accumulator and the carry flag are added.
The result is stored in the Accumulator.
ACC ← ACC + [m] + C
OV, Z, AC, C, SC
LADCM A,[m]
Description
Operation
Affected flag(s)
Add ACC to Data Memory with Carry
The contents of the specified Data Memory, Accumulator and the carry flag are added. The result is stored in the specified Data Memory.
[m] ← ACC + [m] + C
OV, Z, AC, C, SC
LADD A,[m]
Description
The contents of the specified Data Memory and the Accumulator are added.
The result is stored in the Accumulator.
Operation
Affected flag(s)
ACC ← ACC + [m]
OV, Z, AC, C, SC
LADDM A,[m]
Description
Operation
Affected flag(s)
Add ACC to Data Memory
The contents of the specified Data Memory and the Accumulator are added. The result is stored in the specified Data Memory.
[m] ← ACC + [m]
OV, Z, AC, C, SC
LAND A,[m]
Description
Operation
Affected flag(s)
Logical AND Data Memory to ACC
Data in the Accumulator and the specified Data Memory perform a bitwise logical AND operation. The result is stored in the Accumulator.
ACC ← ACC ″AND″ [m]
Z
LANDM A,[m]
Description
Operation
Affected flag(s)
Logical AND ACC to Data Memory
Data in the specified Data Memory and the Accumulator perform a bitwise logical AND
operation. The result is stored in the Data Memory.
[m] ← ACC ″AND″ [m]
Z
LCLR [m]
Description
Operation
Affected flag(s)
Clear Data Memory
Each bit of the specified Data Memory is cleared to 0.
[m] ← 00H
None
LCLR [m].i
Description
Operation
Affected flag(s)
Clear bit of Data Memory
Bit i of the specified Data Memory is cleared to 0.
[m].i ← 0
None
Rev. 1.00
Add Data Memory to ACC
185
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
LCPL [m]
Description
Operation
Affected flag(s)
Complement Data Memory
Each bit of the specified Data Memory is logically complemented (1′s complement). Bits which
previously contained a 1 are changed to 0 and vice versa.
[m] ← [m]
Z
LCPLA [m]
Description
Operation
Affected flag(s)
Complement Data Memory with result in ACC
Each bit of the specified Data Memory is logically complemented (1′s complement). Bits which
previously contained a 1 are changed to 0 and vice versa. The complemented result is stored in
the Accumulator and the contents of the Data Memory remain unchanged.
ACC ← [m]
Z
LDAA [m]
Description
Operation
Affected flag(s)
Decimal-Adjust ACC for addition with result in Data Memory
Convert the contents of the Accumulator value to a BCD (Binary Coded Decimal) value
resulting from the previous addition of two BCD variables. If the low nibble is greater than 9
or if AC flag is set, then a value of 6 will be added to the low nibble. Otherwise the low nibble
remains unchanged. If the high nibble is greater than 9 or if the C flag is set, then a value of 6
will be added to the high nibble. Essentially, the decimal conversion is performed by adding
00H, 06H, 60H or 66H depending on the Accumulator and flag conditions. Only the C flag
may be affected by this instruction which indicates that if the original BCD sum is greater than
100, it allows multiple precision decimal addition.
[m] ← ACC + 00H or
[m] ← ACC + 06H or [m] ← ACC + 60H or
[m] ← ACC + 66H
C
LDEC [m]
Description
Operation
Affected flag(s)
Decrement Data Memory
Data in the specified Data Memory is decremented by 1.
[m] ← [m] − 1
Z
LDECA [m]
Description
Operation
Affected flag(s)
Decrement Data Memory with result in ACC
Data in the specified Data Memory is decremented by 1. The result is stored in the
Accumulator. The contents of the Data Memory remain unchanged.
ACC ← [m] − 1
Z
LINC [m]
Description
Operation
Affected flag(s)
Increment Data Memory
Data in the specified Data Memory is incremented by 1.
[m] ← [m] + 1
Z
LINCA [m]
Description
Operation
Affected flag(s)
Increment Data Memory with result in ACC
Data in the specified Data Memory is incremented by 1. The result is stored in the Accumulator.
The contents of the Data Memory remain unchanged.
ACC ← [m] + 1
Z
Rev. 1.00
186
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
LMOV A,[m]
Description
Operation
Affected flag(s)
Move Data Memory to ACC
The contents of the specified Data Memory are copied to the Accumulator.
ACC ← [m]
None
LMOV [m],A
Description
Operation
Affected flag(s)
Move ACC to Data Memory
The contents of the Accumulator are copied to the specified Data Memory.
[m] ← ACC
None
LOR A,[m]
Description
Operation
Affected flag(s)
Logical OR Data Memory to ACC
Data in the Accumulator and the specified Data Memory perform a bitwise
logical OR operation. The result is stored in the Accumulator.
ACC ← ACC ″OR″ [m]
Z
LORM A,[m]
Description
Operation
Affected flag(s)
Logical OR ACC to Data Memory
Data in the specified Data Memory and the Accumulator perform a bitwise logical OR operation. The result is stored in the Data Memory.
[m] ← ACC ″OR″ [m]
Z
LRL [m]
Description
Operation
Affected flag(s)
Rotate Data Memory left
The contents of the specified Data Memory are rotated left by 1 bit with bit 7 rotated into bit 0.
[m].(i+1) ← [m].i; (i=0~6)
[m].0 ← [m].7
None
LRLA [m]
Description
Operation
Affected flag(s)
Rotate Data Memory left with result in ACC
The contents of the specified Data Memory are rotated left by 1 bit with bit 7 rotated into bit 0.
The rotated result is stored in the Accumulator and the contents of the Data Memory remain
unchanged.
ACC.(i+1) ← [m].i; (i=0~6)
ACC.0 ← [m].7
None
LRLC [m]
Description
Operation
Affected flag(s)
Rotate Data Memory left through Carry
The contents of the specified Data Memory and the carry flag are rotated left by 1 bit. Bit 7
replaces the Carry bit and the original carry flag is rotated into bit 0.
[m].(i+1) ← [m].i; (i=0~6)
[m].0 ← C
C ← [m].7
C
LRLCA [m]
Description
Operation
Affected flag(s)
Rotate Data Memory left through Carry with result in ACC
Data in the specified Data Memory and the carry flag are rotated left by 1 bit. Bit 7 replaces the
Carry bit and the original carry flag is rotated into the bit 0. The rotated result is stored in the
Accumulator and the contents of the Data Memory remain unchanged.
ACC.(i+1) ← [m].i; (i=0~6)
ACC.0 ← C
C ← [m].7
C
Rev. 1.00
187
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
LRR [m]
Description
Operation
Affected flag(s)
Rotate Data Memory right
The contents of the specified Data Memory are rotated right by 1 bit with bit 0 rotated into bit 7.
[m].i ← [m].(i+1); (i=0~6)
[m].7 ← [m].0
None
LRRA [m]
Description
Operation
Affected flag(s)
Rotate Data Memory right with result in ACC
Data in the specified Data Memory and the carry flag are rotated right by 1 bit with bit 0
rotated into bit 7. The rotated result is stored in the Accumulator and the contents of the
Data Memory remain unchanged.
ACC.i ← [m].(i+1); (i=0~6)
ACC.7 ← [m].0
None
LRRC [m]
Description
Operation
Affected flag(s)
Rotate Data Memory right through Carry
The contents of the specified Data Memory and the carry flag are rotated right by 1 bit. Bit 0
replaces the Carry bit and the original carry flag is rotated into bit 7.
[m].i ← [m].(i+1); (i=0~6)
[m].7 ← C
C ← [m].0
C
LRRCA [m]
Description
Operation
Affected flag(s)
Rotate Data Memory right through Carry with result in ACC
Data in the specified Data Memory and the carry flag are rotated right by 1 bit. Bit 0 replaces the Carry bit and the original carry flag is rotated into bit 7. The rotated result is stored in the Accumulator and the contents of the Data Memory remain unchanged.
ACC.i ← [m].(i+1); (i=0~6)
ACC.7 ← C
C ← [m].0
C
LSBC A,[m]
Description
Operation
Affected flag(s)
Subtract Data Memory from ACC with Carry
The contents of the specified Data Memory and the complement of the carry flag are
subtracted from the Accumulator. The result is stored in the Accumulator. Note that if the result of subtraction is negative, the C flag will be cleared to 0, otherwise if the result is
positive or zero, the C flag will be set to 1.
ACC ← ACC − [m] − C
OV, Z, AC, C, SC, CZ
LSBCM A,[m]
Description
Operation
Affected flag(s)
Subtract Data Memory from ACC with Carry and result in Data Memory
The contents of the specified Data Memory and the complement of the carry flag are subtracted from the Accumulator. The result is stored in the Data Memory. Note that if the result of subtraction is negative, the C flag will be cleared to 0, otherwise if the result is positive or zero, the C flag will be set to 1.
[m] ← ACC − [m] − C
OV, Z, AC, C, SC, CZ
Rev. 1.00
188
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
LSDZ [m]
Description
Operation
Affected flag(s)
Skip if decrement Data Memory is 0
The contents of the specified Data Memory are first decremented by 1. If the result is 0 the following instruction is skipped. As this requires the insertion of a dummy instruction while the next instruction is fetched, it is a two cycle instruction. If the result is not 0 the program proceeds with the following instruction.
[m] ← [m] − 1
Skip if [m]=0
None
LSDZA [m]
Description
Operation
Affected flag(s)
Skip if decrement Data Memory is zero with result in ACC
The contents of the specified Data Memory are first decremented by 1. If the result is 0, the following instruction is skipped. The result is stored in the Accumulator but the specified Data Memory contents remain unchanged. As this requires the insertion of a dummy
instruction while the next instruction is fetched, it is a two cycle instruction. If the result is not 0,
the program proceeds with the following instruction.
ACC ← [m] − 1
Skip if ACC=0
None
LSET [m]
Description
Operation
Affected flag(s)
Set Data Memory
Each bit of the specified Data Memory is set to 1.
[m] ← FFH
None
LSET [m].i
Description
Operation
Affected flag(s)
Set bit of Data Memory
Bit i of the specified Data Memory is set to 1.
[m].i ← 1
None
LSIZ [m]
Description
Operation
Affected flag(s)
Skip if increment Data Memory is 0
The contents of the specified Data Memory are first incremented by 1. If the result is 0, the
following instruction is skipped. As this requires the insertion of a dummy instruction while the next instruction is fetched, it is a two cycle instruction. If the result is not 0 the program
proceeds with the following instruction.
[m] ← [m] + 1
Skip if [m]=0
None
LSIZA [m]
Description
Operation
Affected flag(s)
Skip if increment Data Memory is zero with result in ACC
The contents of the specified Data Memory are first incremented by 1. If the result is 0, the following instruction is skipped. The result is stored in the Accumulator but the specified
Data Memory contents remain unchanged. As this requires the insertion of a dummy
instruction while the next instruction is fetched, it is a two cycle instruction. If the result is not
0 the program proceeds with the following instruction.
ACC ← [m] + 1
Skip if ACC=0
None
LSNZ [m].i
Description
Operation
Affected flag(s)
Skip if Data Memory is not 0
If the specified Data Memory is not 0, the following instruction is skipped. As this requires the
insertion of a dummy instruction while the next instruction is fetched, it is a two cycle instruction. If the result is 0 the program proceeds with the following instruction.
Skip if [m].i ≠ 0
None
Rev. 1.00
189
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
LSNZ [m]
Description
Operation
Affected flag(s)
Skip if Data Memory is not 0
If the content of the specified Data Memory is not 0, the following instruction is skipped. As this requires the insertion of a dummy instruction while the next instruction is fetched, it is a two cycle instruction. If the result is 0 the program proceeds with the following instruction.
Skip if [m] ≠ 0
None
LSUB A,[m]
Description
Operation
Affected flag(s)
Subtract Data Memory from ACC
The specified Data Memory is subtracted from the contents of the Accumulator. The result is stored in the Accumulator. Note that if the result of subtraction is negative, the C flag will be cleared to 0, otherwise if the result is positive or zero, the C flag will be set to 1.
ACC ← ACC − [m]
OV, Z, AC, C, SC, CZ
LSUBM A,[m]
Description
Operation
Affected flag(s)
Subtract Data Memory from ACC with result in Data Memory
The specified Data Memory is subtracted from the contents of the Accumulator. The result is stored in the Data Memory. Note that if the result of subtraction is negative, the C flag will be cleared to 0, otherwise if the result is positive or zero, the C flag will be set to 1.
[m] ← ACC − [m]
OV, Z, AC, C, SC, CZ
LSWAP [m]
Description
Operation
Affected flag(s)
Swap nibbles of Data Memory
The low-order and high-order nibbles of the specified Data Memory are interchanged.
[m].3~[m].0 ↔ [m].7~[m].4
None
LSWAPA [m]
Description
Operation
Affected flag(s)
Swap nibbles of Data Memory with result in ACC
The low-order and high-order nibbles of the specified Data Memory are interchanged. The result is stored in the Accumulator. The contents of the Data Memory remain unchanged.
ACC.3~ACC.0 ← [m].7~[m].4
ACC.7~ACC.4 ← [m].3~[m].0
None
LSZ [m]
Description
Operation
Affected flag(s)
Skip if Data Memory is 0
If the contents of the specified Data Memory is 0, the following instruction is skipped. As this requires the insertion of a dummy instruction while the next instruction is fetched, it is a two cycle instruction. If the result is not 0 the program proceeds with the following instruction.
Skip if [m]=0
None
LSZA [m]
Description
Operation
Affected flag(s)
Skip if Data Memory is 0 with data movement to ACC
The contents of the specified Data Memory are copied to the Accumulator. If the value is zero, the following instruction is skipped. As this requires the insertion of a dummy instruction while the next instruction is fetched, it is a two cycle instruction. If the result is not 0 the program proceeds with the following instruction.
ACC ← [m]
Skip if [m]=0
None
Rev. 1.00
190
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
LSZ [m].i
Description
Operation
Affected flag(s)
Skip if bit i of Data Memory is 0
If bit i of the specified Data Memory is 0, the following instruction is skipped. As this requires
the insertion of a dummy instruction while the next instruction is fetched, it is a two cycle
instruction. If the result is not 0, the program proceeds with the following instruction.
Skip if [m].i=0
None
LTABRD [m]
Description
Operation
Affected flag(s)
Read table (current page) to TBLH and Data Memory
The low byte of the program code (current page) addressed by the table pointer (TBLP) is moved to the specified Data Memory and the high byte moved to TBLH.
[m] ← program code (low byte)
TBLH ← program code (high byte)
None
LTABRDL [m]
Description
Operation
Affected flag(s)
Read table (last page) to TBLH and Data Memory
The low byte of the program code (last page) addressed by the table pointer (TBLP) is moved to the specified Data Memory and the high byte moved to TBLH.
[m] ← program code (low byte)
TBLH ← program code (high byte)
None
LITABRD [m]
Description
Operation
Increment table pointer low byte first and read table to TBLH and Data Memory
Increment table pointer low byte, TBLP, first and then the program code addressed by the table pointer (TBHP and TBLP) is moved to the specified Data Memory and the high byte moved to TBLH.
[m] ← program code (low byte)
TBLH ← program code (high byte)
Affected flag(s)
None
LITABRDL [m]
Description
Operation
Affected flag(s)
Increment table pointer low byte first and read table (last page) to TBLH and Data Memory
Increment table pointer low byte, TBLP, first and then the low byte of the program code (last page) addressed by the table pointer (TBLP) is moved to the specified Data Memory and the high byte moved to TBLH.
[m] ← program code (low byte)
TBLH ← program code (high byte)
None
LXOR A,[m]
Description
Operation
Affected flag(s)
Logical XOR Data Memory to ACC
Data in the Accumulator and the specified Data Memory perform a bitwise logical XOR operation. The result is stored in the Accumulator.
ACC ← ACC ″XOR″ [m]
Z
LXORM A,[m]
Description
Operation
Affected flag(s)
Logical XOR ACC to Data Memory
Data in the specified Data Memory and the Accumulator perform a bitwise logical XOR operation. The result is stored in the Data Memory.
[m] ← ACC ″XOR″ [m]
Z
Rev. 1.00
191
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Package Information
Note that the package information provided here is for consultation purposes only. As this
information may be updated at regular intervals users are reminded to consult the Holtek website for
the latest version of the package information.
Additional supplementary information with regard to packaging is listed below. Click on the relevant
section to be transferred to the relevant website page.
• Further Package Information (include Outline Dimensions, Product Tape and Reel Specifications)
• Packing Meterials Information
• Carton information
Rev. 1.00
192
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
28-pin SOP (300mil) Outline Dimensions
Symbol
Dimensions in inch
Min.
Nom.
Max.
A
—
0.406 BSC
—
B
—
0.295 BSC
—
C
0.012
—
0.020
C’
—
0.705 BSC
—
D
—
—
0.104
E
—
0.050 BSC
—
F
0.004
—
0.012
G
0.016
—
0.050
H
0.008
—
0.013
α
0°
—
8°
Symbol
Rev. 1.00
Dimensions in mm
Min.
Nom.
Max.
—
A
—
10.30 BSC
B
—
7.50 BSC
—
C
0.31
—
0.51
C’
—
17.9 BSC
—
D
—
—
2.65
E
—
1.27 BSC
—
F
0.10
—
0.30
G
0.40
—
1.27
H
0.20
—
0.33
α
0°
—
8°
193
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
28-pin SSOP (150mil) Outline Dimensions
Symbol
Dimensions in inch
Min.
Nom.
Max.
—
A
—
0.236 BSC
B
—
0.154 BSC
—
C
0.008
—
0.012
C’
—
0.390 BSC
—
D
—
—
0.069
E
—
0.025 BSC
—
F
0.004
—
0.010
G
0.016
—
0.050
H
0.004
—
0.010
α
0°
—
8°
Symbol
A
Rev. 1.00
Dimensions in mm
Min.
Nom.
Max.
—
6.0 BSC
—
B
—
3.9 BSC
—
C
0.20
—
0.30
C’
—
9.9 BSC
—
D
—
—
1.75
E
—
0.635 BSC
—
F
0.10
—
0.25
G
0.41
—
1.27
H
0.10
—
0.25
α
0°
—
8°
194
September 25, 2014
HT66F488/HT66F489
A/D 8-Bit Flash MCU with EEPROM
Copyright© 2014 by HOLTEK SEMICONDUCTOR INC.
The information appearing in this Data Sheet is believed to be accurate at the time
of publication. However, Holtek assumes no responsibility arising from the use of
the specifications described. The applications mentioned herein are used solely
for the purpose of illustration and Holtek makes no warranty or representation that
such applications will be suitable without further modification, nor recommends
the use of its products for application that may present a risk to human life due to
malfunction or otherwise. Holtek's products are not authorized for use as critical
components in life support devices or systems. Holtek reserves the right to alter
its products without prior notification. For the most up-to-date information, please
visit our web site at http://www.holtek.com.tw.
Rev. 1.00
195
September 25, 2014