HT66F24D/HT66F25D/HT66F26D

Enhanced A/D Flash 8-bit MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Revision: V1.30
Date: ��������������
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Table of Contents
Features............................................................................................................. 6
CPU Features.......................................................................................................................... 6
Peripheral Features.................................................................................................................. 6
General Description.......................................................................................... 7
Selection Table.................................................................................................. 7
Block Diagram................................................................................................... 8
Pin Assignment................................................................................................. 9
Pin Descriptions..............................................................................................11
HT66F24D...............................................................................................................................11
HT66F25D.............................................................................................................................. 12
HT66F26D.............................................................................................................................. 13
Absolute Maximum Ratings........................................................................... 14
D.C. Characteristics........................................................................................ 14
A.C. Characteristics........................................................................................ 16
LVD and LVR Electrical Characteristics........................................................ 17
A/D Converter Characteristics....................................................................... 18
Power-on Reset Characteristics.................................................................... 19
System Architecture....................................................................................... 19
Clocking and Pipelining.......................................................................................................... 19
Program Counter.................................................................................................................... 20
Stack...................................................................................................................................... 21
Arithmetic and Logic Unit – ALU............................................................................................ 22
Flash Program Memory.................................................................................. 22
Structure................................................................................................................................. 22
Special Vectors...................................................................................................................... 23
Look-up Table......................................................................................................................... 23
Table Program Example......................................................................................................... 23
In Circuit Programming.......................................................................................................... 24
On-Chip Debug Support – OCDS.......................................................................................... 25
RAM Data Memory.......................................................................................... 26
Structure................................................................................................................................. 26
Special Function Register Description......................................................... 31
Indirect Addressing Registers – IAR0, IAR1.......................................................................... 31
Memory Pointers – MP0, MP1............................................................................................... 31
Bank Pointer – BP.................................................................................................................. 32
Accumulator – ACC................................................................................................................ 32
Program Counter Low Register – PCL................................................................................... 33
Look-up Table Registers – TBLP, TBHP, TBLH...................................................................... 33
Status Register – STATUS..................................................................................................... 33
Rev. 1.30
2
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
EEPROM Data Memory................................................................................... 35
EEPROM Data Memory Structure......................................................................................... 35
EEPROM Registers............................................................................................................... 35
Reading Data from the EEPROM.......................................................................................... 37
Writing Data to the EEPROM................................................................................................. 37
Write Protection...................................................................................................................... 37
EEPROM Interrupt................................................................................................................. 37
Programming Considerations................................................................................................. 38
Oscillator......................................................................................................... 39
Oscillator Overview................................................................................................................ 39
System Clock Configurations................................................................................................. 39
External Crystal/Ceramic Oscillator – HXT............................................................................ 40
Internal High Speed RC Oscillator – HIRC............................................................................ 41
Internal 32kHz Oscillator – LIRC............................................................................................ 41
Supplementary Oscillator....................................................................................................... 41
Operating Modes and System Clocks.......................................................... 42
System Clocks....................................................................................................................... 42
System Operation Modes....................................................................................................... 43
Control Register..................................................................................................................... 44
Fast Wake-up......................................................................................................................... 46
Operating Mode Switching..................................................................................................... 47
Standby Current Considerations............................................................................................ 51
Wake-up................................................................................................................................. 51
Programming Considerations................................................................................................. 51
Watchdog Timer.............................................................................................. 52
Watchdog Timer Clock Source............................................................................................... 52
Watchdog Timer Control Register.......................................................................................... 52
Watchdog Timer Operation.................................................................................................... 53
Reset and Initialisation................................................................................... 54
Reset Functions..................................................................................................................... 55
Reset Initial Conditions.......................................................................................................... 57
Input/Output Ports.......................................................................................... 64
I/O Resistor Lists.................................................................................................................... 64
Pull-high Resistors................................................................................................................. 65
Port A Wake-up...................................................................................................................... 66
Pin-remapping Functions....................................................................................................... 68
Rev. 1.30
3
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Timer Modules – TM....................................................................................... 70
Introduction............................................................................................................................ 70
TM Operation......................................................................................................................... 71
TM Clock Source.................................................................................................................... 71
TM Interrupts.......................................................................................................................... 71
TM External Pins.................................................................................................................... 72
TM Input/Output Pin Control Registers.................................................................................. 72
Programming Considerations................................................................................................. 79
Compact Type TM –
­­ CTM............................................................................... 80
Compact TM Operation.......................................................................................................... 80
Compact Type TM Register Description................................................................................ 81
Compact Type TM Operation Modes..................................................................................... 85
Standard Type TM – STM............................................................................... 91
Standard TM Operation.......................................................................................................... 91
Standard Type TM Register Description................................................................................ 92
Standard Type TM Operation Modes..................................................................................... 96
Capture Input Mode............................................................................................................. 104
Enhanced Type TM – ETM............................................................................ 106
Enhanced TM Operation...................................................................................................... 106
Enhanced Type TM Register Description............................................................................. 107
Enhanced Type TM Operation Modes..................................................................................114
Analog to Digital Converter......................................................................... 130
A/D Overview....................................................................................................................... 130
A/D Converter Register Description..................................................................................... 130
A/D Operation...................................................................................................................... 134
A/D Input Pins...................................................................................................................... 135
Summary of A/D Conversion Steps...................................................................................... 136
Programming Considerations............................................................................................... 137
A/D Transfer Function.......................................................................................................... 137
A/D Programming Examples................................................................................................ 138
Interrupts....................................................................................................... 140
Interrupt Registers................................................................................................................ 140
Interrupt Operation............................................................................................................... 147
External Interrupt.................................................................................................................. 149
Multi-function Interrupt......................................................................................................... 149
A/D Converter Interrupt........................................................................................................ 150
Time Base Interrupt.............................................................................................................. 150
LVD Interrupt........................................................................................................................ 152
TM Interrupt.......................................................................................................................... 152
Interrupt Wake-up Function.................................................................................................. 152
Programming Considerations............................................................................................... 153
Rev. 1.30
4
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Low Voltage Detector – LVD........................................................................ 154
LVD Register........................................................................................................................ 154
LVD Operation...................................................................................................................... 155
Configuration Options.................................................................................. 156
Application Circuit........................................................................................ 156
Instruction Set............................................................................................... 157
Introduction.......................................................................................................................... 157
Instruction Timing................................................................................................................. 157
Moving and Transferring Data.............................................................................................. 157
Arithmetic Operations........................................................................................................... 157
Logical and Rotate Operations............................................................................................. 158
Branches and Control Transfer............................................................................................ 158
Bit Operations...................................................................................................................... 158
Table Read Operations........................................................................................................ 158
Other Operations.................................................................................................................. 158
Instruction Set Summary............................................................................. 159
Table Conventions................................................................................................................ 159
Package Information.................................................................................... 170
16-pin DIP (300mil) Outline Dimensions.............................................................................. 171
16-pin NSOP (150mil) Outline Dimensions.......................................................................... 173
20-pin DIP (300mil) Outline Dimensions.............................................................................. 174
20-pin SOP (300mil) Outline Dimensions............................................................................ 176
24-pin SOP (300mil) Outline Dimensions............................................................................ 179
28-pin SKDIP (300mil) Outline Dimensions......................................................................... 180
28-pin SOP (300mil) Outline Dimensions............................................................................ 181
Rev. 1.30
5
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Features
CPU Features
• Operating voltage:
♦♦
fSYS= 8MHz: 2.2V~5.5V
♦♦
fSYS= 12MHz: 2.7V~5.5V
♦♦
fSYS= 20MHz: 4.5V~5.5V
• Up to 0.2μs instruction cycle with 20MHz system clock at VDD= 5V
• Power down and wake-up functions to reduce power consumption
• Three Oscillator types
♦♦
External high frequency Crystal – HXT
♦♦
Internal RC – HIRC
♦♦
Internal 32kHz RC – LIRC
• Multi-mode operation: NORMAL, SLOW, IDLE and SLEEP
• Fully integrated internal 4MHz, 8MHz and 12MHz oscillator requires no external components
• All instructions executed in one or two instruction cycles
• Table read instructions
• 63 powerful instructions
• 8-level subroutine nesting
• Bit manipulation instruction
Peripheral Features
• Program Memory: 2K × 16 ~ 8K × 16
• Data Memory: 96 × 8 ~ 384 × 8
• EEPROM Memory: 64 × 8
• Watchdog Timer function
• Up to 26 bidirectional I/O lines
• Multiple pin-shared external interrupts
• Multiple Timer Module for time measure, input capture, compare match output, PWM output or
single pulse output function
• Dual Time-Base functions for generation of fixed time interrupt signal
• Up to 8 channels 12-bit A/D converter
• Low voltage reset function
• Low voltage detect function
• LED Driver
• Wide range of available package types
Rev. 1.30
6
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
General Description
The series of devices are Flash Memory A/D type 8-bit high performance RISC architecture
microcontrollers. Offering users the convenience of Flash Memory multi-programming features,
these devices also include a wide range of functions and features. Other memory includes an area of
RAM Data Memory for application program data storage.
Analog feature includes a multi-channel 12-bit A/D converter. Multiple and extremely flexible Timer
Modules provide timing, pulse generation and PWM generation functions. 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, 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 minimise power consumption.
The inclusion of flexible I/O programming features, Time-Base functions along with many other
features ensure that the devices will find excellent use in applications such as electronic metering,
environmental monitoring, handheld instruments, household appliances, electronically controlled
tools, motor driving in addition to many others.
Selection Table
Most features are common to all devices, the main feature distinguishing them are Memory capacity,
I/O count, TM features and package types. The following table summarises the main features of
each device.
Part No.
VDD
Program
Memory
Data
Memory
Data
EEPROM
I/O
External
Interrupt
HT66F24D
2.2V~5.5V
2k × 16
96 × 8
64 × 8
22
2
HT66F25D
2.2V~5.5V
4k × 16
192 × 8
64 × 8
26
2
HT66F26D
2.2V~5.5V
8k × 16
384 × 8
64 × 8
26
2
Part No.
A/D
Converter
Timer
Module
LED
Driver
Stacks
Package
HT66F24D
12-bit × 8
10-bit CTM × 1
10-bit STM × 1
8×6
8
16DIP/NSOP
20DIP/SOP
24SKDIP/SOP
HT66F25D
12-bit × 8
10-bit CTM × 1
10-bit ETM × 1
8×8
8
20DIP/SOP
24/28SKDIP/SOP
HT66F26D
12-bit × 8
10-bit CTM × 1
10-bit STM × 1
10-bit ETM × 1
8×8
8
24/28SKDIP/SOP
Note: As devices exist in more than one package format, the table reflects the situation for the package with the
most pins.
Rev. 1.30
7
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Block Diagram
Low
Voltage
Detect
Low
Voltage
Reset
Flash/EEPROM
Programming
Circuitry (ISP)
Flash
Program
Memory
Watchdog
Timer
Stack
EEPROM
Data
Memory
TB0/TB1
RAM
Data
Memory
Reset
Circuit
8-bit
RISC
MCU
Core
Interrupt
Controller
HXT
Oscillator
HIRC
Oscillator
LIRC/LXT
Oscillator
12-Bit A/D
Converter
I/O
Rev. 1.30
TM0
TM1
TM2
8
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Pin Assignment
P A 0 /T P 0 _ 1 /A N 0
1
P A 1 /T P 1 _ 1 /A N 1
P A 0 /T P 0 _ 1 /A N 0
2
1 5
3
1 4
4
1 3
5
1 2
6
1 1
7
1 0
8
9
P A 1 /T P 1 _ 1 /A N 1
1 6
P A 2 /IN T 0 /A N 2 /V R E F
V S S
P B 2 /A N 7
P B 1 /T P 1 _ 2 /A N 6
P A 7 /T P 0 _ 2
P C 0 /[IN T 0 ]
P A 2 /IN T 0 /A N 2 /V R E F
P B 0 /IN T 1 /T C K 1
1
1
P A 1 /T P 1 _ 1 /A N 1
2
P A 2 /IN T 0 /A N 2 /V R E F
3
V S S
4
P B 5 /A N 5
5
P B 4 /A N 4
6
P B 3 /A N 3
7
P B 2 /A N 7
8
P B 1 /T P 1 _ 2 /A N 6
9
2 4
2 3
2 2
2 1
2 0
1 9
1 8
1 7
P A 7 /T P 0 _ 2
1 0
P C 0 /[IN T 0 ]
1 1
P C 1 /[IN T 1 ]
1 2
1 6
1 5
1 4
1 3
P A 6 /T C K 0 /O S C 1
P B 3 /A N 3
P A 3 /T P 0 _ 0 /X T 2
P B 2 /A N 7
P A 4 /T P 1 _ 0 /X T 1
P B 1 /T P 1 _ 2 /A N 6
V D D
P A 7 /T P 0 _ 2
P C 2 /[T C K 0 ]
P C 0 /[IN T 0 ]
P C 1 /[IN T 1 ]
P C 1 /[IN T 1 ]
1
P A 1 /T P 1 B _ 1 /A N 1
2
P A 2 /IN T 0 /A N 2 /V R E F
3
V S S
4
P B 5 /A N 5
5
P B 4 /A N 4
6
P B 3 /A N 3
7
P B 2 /T P 1 A _ 1
8
P B 1 /T P 1 B _ 2
9
2 4
2 3
2 2
2 1
2 0
1 9
1 8
1 7
P A 7 /T P 0 _ 2
1 0
P C 0 /[IN T 0 ]
1 1
P C 1 /[IN T 1 ]
1 2
1 6
1 5
1 4
1 3
5
6
7
8
9
1 0
P B 0 /IN T 1 /T C K 1
1 9
P A 5 /O S C 2
1 8
P A 6 /T C K 0 /O S C 1
1 7
P A 3 /T P 0 _ 0 /X T 2
1 6
P A 4 /T P 1 _ 0 /X T 1
1 5
V D D
1 4
P C 5
1 3
P C 4
1 2
P C 3 /[T C K 1 ]
1 1
P C 2 /[T C K 0 ]
P B 0 /IN T 1 /T C K 1
P A 5 /O S C 2
P A 6 /T C K 0 /O S C 1
P A 0 /T P 0 _ 1 /A N 0
P A 3 /T P 0 _ 0 /X T 2
P A 1 /T P 1 B _ 1 /A N 1
P A 4 /T P 1 _ 0 /X T 1
P A 2 /IN T 0 /A N 2 /V R E F
V D D
V S S
P C 7
P B 3 /A N 3
P C 6
P B 2 /T P 1 A _ 1
P C 5
P B 1 /T P 1 B _ 2
P C 4
P A 7 /T P 0 _ 2
P C 3 /[T C K 1 ]
P C 0 /[IN T 0 ]
P C 2 /[T C K 0 ]
P C 1 /[IN T 1 ]
2 0
1
2
3
4
5
6
7
8
9
1 0
P B 0 /IN T 1 /T C K 1
1 9
P A 5 /T P 1 A _ 0 /O S C 2
1 8
P A 6 /T C K 0 /O S C 1
1 7
P A 3 /T P 0 _ 0 /X T 2
1 6
P A 4 /T P 1 B _ 0 /X T 1
1 5
V D D
1 4
P C 5
1 3
P C 4
1 2
P C 3 /[T C K 1 ]
1 1
P C 2 /[T C K 0 ]
 P B 0 /IN T 1 /T C K 1
P A 0 /T P 0 _ 1 /A N 0
1
2 8
P A 1 /T P 1 B _ 1 /A N 1
2
2 7
P B 0 /IN T 1 /T C K 1
P A 5 /T P 1 A _ 0 /O S C 2
P A 2 /IN T 0 /A N 2 /V R E F
3
2 6
P A 6 /T C K 0 /O S C 1
V S S
4
2 5
P A 3 /T P 0 _ 0 /X T 2
P A 6 /T C K 0 /O S C 1
P B 7 /A N 7
5
2 4
P A 4 /T P 1 B _ 0 /X T 1
P A 3 /T P 0 _ 0 /X T 2
P B 6 /A N 6
6
2 3
V D D
P A 4 /T P 1 B _ 0 /X T 1
P B 5 /A N 5
7
2 2
P D 0
V D D
P B 4 /A N 4
8
2 1
P D 1
P C 7
P B 3 /A N 3
9
2 0
P C 7
P C 6
P B 2 /T P 1 A _ 1
1 0
1 9
P C 6
P C 5
P B 1 /T P 1 B _ 2
1 1
1 8
P C 5
P C 4
P A 7 /T P 0 _ 2
1 2
1 7
P C 4
P C 3 /[T C K 1 ]
P C 0 /[IN T 0 ]
1 3
1 6
P C 3 /[T C K 1 ]
P C 2 /[T C K 0 ]
P C 1 /[IN T 1 ]
1 4
1 5
P C 2 /[T C K 0 ]
P A 5 /T P 1 A _ 0 /O S C 2
Rev. 1.30
4
2 0
 P A 0 /T P 0 _ 1 /A N 0
3
V S S
P A 5 /O S C 2
   P A 0 /T P 0 _ 1 /A N 0
2
9
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
P A 0 /T P 0 _ 1 /A N 0
1
P A 1 /T P 1 B _ 1 /A N 1
2
P A 2 /IN T 0 /A N 2 /V R E F
3
V S S
4
P B 5 /A N 5
5
P B 4 /A N 4
6
P B 3 /A N 3
7
P B 2 /T P 1 A _ 1
8
P B 1 /T P 1 B _ 2
9
2 4
2 3
2 2
2 1
2 0
1 9
1 8
1 7
P A 7 /T P 0 _ 2
1 0
P C 0 /[IN T 0 ]
1 1
P C 1 /[IN T 1 ]
1 2
1 6
1 5
1 4
1 3
P B 0 /IN T 1 /T C K 1
P A 0 /T P 0 _ 1 /A N 0
1
2 8
P A 1 /T P 1 B _ 1 /A N 1
2
2 7
P A 5 /T P 1 A _ 0 /O S C 2
P A 2 /IN T 0 /A N 2 /V R E F
3
2 6
P A 6 /T C K 0 /O S C 1
P B 0 /IN T 1 /T C K 1
V S S
4
2 5
P A 3 /T P 0 _ 0 /X T 2
P A 6 /T C K 0 /O S C 1
P B 7 /A N 7
5
2 4
P A 4 /T P 1 B _ 0 /X T 1
P A 3 /T P 0 _ 0 /X T 2
P B 6 /A N 6
6
2 3
V D D
P A 4 /T P 1 B _ 0 /X T 1
P B 5 /A N 5
7
2 2
P D 0
V D D
P B 4 /A N 4
8
2 1
P D 1
P C 7 /T C K 2
P B 3 /A N 3
9
2 0
P C 7 /T C K 2
P A 5 /T P 1 A _ 0 /O S C 2
P C 6 /T P 2 _ 2
P B 2 /T P 1 A _ 1
1 0
1 9
P C 6 /T P 2 _ 2
P C 5 /T P 2 _ 1
P B 1 /T P 1 B _ 2
1 1
1 8
P C 5 /T P 2 _ 1
P C 4 /T P 2 _ 0
P A 7 /T P 0 _ 2
1 2
1 7
P C 4 /T P 2 _ 0
P C 3 /[T C K 1 ]
P C 0 /[IN T 0 ]
1 3
1 6
P C 3 /[T C K 1 ]
P C 2 /[T C K 0 ]
P C 1 /[IN T 1 ]
1 4
1 5
P C 2 /[T C K 0 ]
H T 6 6 F 2 6 D
2 4 S K D IP -A /S O P -A
L E D 8 x 6 (S o u r c e /S in k )
H T 6 6 F 2 6 D
2 8 S K D IP -A /S O P -A
L E D 8 x 8 (S o u r c e /S in k )
P A 0 /T P 0 _ 1 /A N 0 /O C D S D A
1
2 8
P B 0 /IN T 1 /T C K 1 /O C D S C K
P A 1 /T P 1 B _ 1 /A N 1
2
2 7
P A 5 /T P 1 A _ 0 /O S C 2
P A 2 /IN T 0 /A N 2 /V R E F
3
2 6
P A 6 /T C K 0 /O S C 1
V S S
4
2 5
P A 3 /T P 0 _ 0 /X T 2
P B 7 /A N 7
5
2 4
P A 4 /T P 1 B _ 0 /X T 1
P B 6 /A N 6
6
2 3
V D D
P B 5 /A N 5
7
2 2
P D 0
P B 4 /A N 4
8
2 1
P D 1
P B 3 /A N 3
9
2 0
P C 7 /T C K 2
P B 2 /T P 1 A _ 1
1 0
1 9
P C 6 /T P 2 _ 2
P B 1 /T P 1 B _ 2
1 1
1 8
P C 5 /T P 2 _ 1
P A 7 /T P 0 _ 2
1 2
1 7
P C 4 /T P 2 _ 0
P C 0 /[IN T 0 ]
1 3
1 6
P C 3 /[T C K 1 ]
P C 1 /[IN T 1 ]
1 4
1 5
P C 2 /[T C K 0 ]
H T 6 6 V 2 6 D
2 8 S K D IP -A /S O P -A
L E D 8 x 8 (S o u r c e /S in k )
Rev. 1.30
10
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Pin Descriptions
With the exception of the power pins, all pins on these devices can be referenced by their Port name,
e.g. PA.0, PA.1 etc, which refer to the digital I/O function of the pins. However some of these Port
pins are also shared with other function such as the Analog to Digital Converter, Timer Module pins
etc. The function of each pin is listed in the following table, however the details behind how each
pin is configured is contained in other sections of the datasheet.
HT66F24D
Pin Name
Function
OP
I/T
O/T
Pin-Shared Mapping
PAWU
PAPU
ST
CMOS
—
—
PA0~PA7
Port A
PB0~PB5
Port B
PBPU
ST
CMOS
PC0~PC7
Port C
PCPU
ST
CMOS
—
—
PA0~PA2,PB3~PB5,
PB1~PB2
AN
—
PA2
ST
—
PA6, PC2
PRM0
ST
—
PB0, PC3
TM0 I/O
TMPC0
ST
CMOS PA3, PA0, PA7
TP1_0, TP1_1, TP1_2
TM1 I/O
TMPC0
ST
CMOS PA4, PA1, PB1
INT0
External Interrupt 0
PRM0
ST
—
PA2, PC0
INT1
External Interrupt 1
PRM0
ST
—
PB0, PC1
OSC1
HXT pin
CO
HXT
—
PA6
OSC2
HXT pin
CO
—
HXT
PA5
VDD
Power supply
—
PWR
—
—
VSS
Ground*
—
PWR
—
—
AN0~AN7
A/D Converter input
ACERL
AN
VREF
A/D Converter reference input
ADCR1
TCK0
TM0 input
PRM0
TCK1
TM1 input
TP0_0, TP0_1, TP0_2
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; NMOS: NMOS output
AN: Analog input pin
HXT: High frequency crystal oscillator
Rev. 1.30
11
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
HT66F25D
Pin Name
Function
OP
I/T
O/T
Pin-Shared Mapping
PAWU
PAPU
ST
CMOS
—
PA0~PA7
Port A
PB0~PB7
Port B
PBPU
ST
CMOS
—
PC0~PC7
Port C
PCPU
ST
CMOS
—
PD0~PD1
Port D
PDPU
ST
CMOS
AN0~AN7
A/D Converter input
ACERL
AN
—
PA0~PA2, PB3~PB7
VREF
A/D Converter
reference input
ADCR1
AN
—
PA2
TCK0
TM0 input
PRM0
ST
—
PA6, PC2
TCK1
TM1 input
PB0, PC3
—
PRM0
ST
—
TP0_0, TP0_1, TP0_2 TM0 I/O
TMPC0
ST
CMOS
PA3, PA0, PA7
TP1A_0, TP1A_1
TM1 I/O
TMPC0
ST
CMOS
PA5, PB2
TP1B_0,TP1B_1,
TP1B_2
TM1 I/O
TMPC0
ST
CMOS
PA4, PA1, PB1
INT0
External Interrupt 0
PRM0
ST
—
INT1
External Interrupt 1
PRM0
ST
—
PB0, PC1
OSC1
HXT pin
CO
HXT
—
PA6
OSC2
HXT pin
CO
—
HXT
PA5
VDD
Power supply
—
PWR
—
—
VSS
Ground*
—
PWR
—
—
PA2, PC0
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; NMOS: NMOS output
AN: Analog input pin
HXT: High frequency crystal oscillator
Rev. 1.30
12
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
HT66F26D
Pin Name
Function
OP
I/T
O/T
Pin-Shared Mapping
PAWU
PAPU
ST
CMOS
—
PA0~PA7
Port A
PB0~PB7
Port B
PBPU
ST
CMOS
—
PC0~PC7
Port C
PCPU
ST
CMOS
—
PD0~PD1
Port D
PDPU
ST
CMOS
—
OCDSDA
OCDS Data/Address, for EV chip
only.
—
ST
CMOS
OCDSCK
OCDS Clock pin, for EV chip only.
—
ST
—
PB0
AN0~AN7
A/D Converter input
ACERL
AN
—
PA0~PA2, PB3~PB7
VREF
A/D Converter reference input
ADCR1
AN
—
PA2
TCK0
TM0 input
PRM0
ST
—
PA6, PC2
TCK1
TM1 input
PRM0
ST
—
PB0, PC3
TCK2
TM2 input
—
ST
TP0_0, TP0_1, TP0_2
TM0 I/O
TMPC0
ST
CMOS
PA3, PA0, PA7
TP1A_0, TP1A_1
TM1 I/O
TMPC0
ST
CMOS
PA5, PB2
TP1B_0, TP1B_1,
TP1B_2
TM1 I/O
TMPC0
ST
CMOS
PA4, PA1, PB1
TP2_0, TP2_1, TP2_2
TM2 I/O
TMPC0
ST
CMOS
PC4, PC5, PC6
INT0
External Interrupt 0
PRM0
ST
—
PA2, PC0
INT1
External Interrupt 1
PRM0
ST
—
PB0, PC1
OSC1
HXT pin
CO
HXT
—
PA6
OSC2
HXT pin
CO
—
HXT
PA5
VDD
Power supply
—
PWR
—
—
VSS
Ground*
—
PWR
—
—
PA0
PC7
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; NMOS: NMOS output
AN: Analog input pin
HXT: High frequency crystal oscillator
Rev. 1.30
13
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Absolute Maximum Ratings
Supply Voltage .................................................................................................VSS-0.3V to VSS+6.0V
Input Voltage ...................................................................................................VSS-0.3V to VDD+0.3V
IOL Total ................................................................................................... 100mA
Total Power Dissipation ......................................................................................................... 500mW
Storage Temperature .................................................................................................. -50°C to 125°C
Operating Temperature . ............................................................................................... -40°C to 85°C
IOH Total.................................................................................................. -100mA
Note: These are stress ratings only. Stresses exceeding the range specified under “Absolute
Maximum Ratings” may cause substantial damage to the device. Functional operation of
this device at other conditions beyond those listed in the specification is not implied and
prolonged exposure to extreme conditions may affect device reliability.
D.C. Characteristics
Ta=25°C
Symbol
VDD
Parameter
Operating Voltage
(HXT/HIRC OSC)
Test Conditions
—
3V
IDD1
Operating Current,
Normal Mode,
fSYS=fH, fS=fSUB=fLIRC
(HXT, HIRC)
5V
3V
5V
3V
5V
IDD2
Operating Current,
Normal Mode,
fSYS=fH, fS=fSUB=fLIRC
(HXT)
IDD3
Operating Current, Slow Mode,
fSYS=fL (LIRC)
IIDLE1
IDLE0 Mode Stanby Current
(LIRC On)
3V
IIDLE2
IDLE1 Mode Stanby Current
(HXT, HIRC)
3V
ISLEEP1
SLEEP0 Mode Stanby Current
(LIRC Off)
3V
ISLEEP2
SLEEP1 Mode Stanby Current
( LIRC On)
3V
Rev. 1.30
Min.
Typ.
Max.
Unit
fSYS=8MHz
2.2
—
5.5
V
fSYS=12MHz
2.7
—
5.5
V
fSYS=20MHz
4.5
—
5.5
V
No load, fH=4MHz, ADC off,
WDT enable
—
0.7
1.1
mA
—
1.8
2.7
mA
No load, fH=8MHz, ADC off,
WDT enable
—
1.6
2.4
mA
—
3.3
5.0
mA
No load, fH=12MHz, ADC off,
WDT enable
—
2.2
3.3
mA
—
5.0
7.5
mA
—
6.0
9.0
mA
—
10
20
μA
—
20
40
μA
VDD
5V
3V
5V
5V
5V
5V
5V
Conditions
No load, fH=20MHz, ADC off,
WDT enable
No load, fSYS=LIRC, ADC off,
WDT enable
No load, ADC off,
WDT enable
No load, ADC off, WDT
enable, fSYS =12MHz on
—
1.5
3.0
μA
—
3.0
6.0
μA
—
0.55
0.83
mA
—
1.30
2.00
mA
No load, ADC off,
WDT disable
—
—
1.0
μA
—
—
2.0
μA
No load, ADC off,
WDT enable
—
1.5
3.0
μA
—
2.5
5.0
μA
14
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Symbol
Parameter
Test Conditions
VDD
Conditions
Min.
Typ.
Max.
Unit
VIL1
Input Low Voltage for I/O Ports
or Input Pins
—
—
0
—
0.3VDD
V
VIH1
Input High Voltage for I/O Ports
or Input Pins
—
—
0.7VDD
—
VDD
V
IOL1
I/O Port Sink Current
(PA0~PA6, PB0, D0~PD1)
3V
VOL= 0.1VDD
4
8
—
mA
5V
VOL= 0.1VDD
10
20
—
mA
IOH1
I/O Port, Source Current
(PA0~PA6, PB0, D0~PD1)
3V
VOH= 0.9VDD
-2
-4
—
mA
5V
VOH= 0.9VDD
-5
-10
—
mA
IOL2
I/O Port Sink Current
(PA7, PB1~PB7)
3V
VOL= 0.1VDD
16
32
—
mA
5V
VOL= 0.1VDD
40
80
—
mA
IOH2
I/O Port, Source Current
(PA7, PB1~PB7)
3V
VOH= 0.9VDD
-2
-4
—
mA
5V
VOH= 0.9VDD
-5
-10
—
mA
IOL3
I/O Port Sink Current
(PC0~PC7)
3V
VOL= 0.1VDD
4
8
—
mA
5V
VOL= 0.1VDD
10
20
—
mA
IOH3
I/O Port, Source Current
(PC0~PC7)
3V
VOH= 0.9VDD
-4
-8
—
mA
5V
VOH= 0.9VDD
-10
-20
—
mA
RPH
Pull-high Resistance of I/O
Ports
3V
—
20
60
100
kΩ
5V
—
10
30
50
kΩ
Rev. 1.30
15
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
A.C. Characteristics
Ta=25°C
Symbol
fCPU
fSYS
fHIRC
Parameter
Operating Clock
System clock (HXT)
System clock (HIRC)
Test Conditions
Min.
Typ.
Max.
Unit
—
DC
—
DC
—
8
MHz
—
12
MHz
4.5~5.5V
—
2.2~5.5V
—
DC
—
20
MHz
0.4
—
8
MHz
2.7~5.5V
4.5~5.5V
—
0.4
—
12
MHz
—
0.4
—
20
MHz
4
+2%
MHz
VDD
Condition
2.2~5.5V
2.7~5.5V
3V/5V
Ta=25°C
-2%
3V/5V
Ta=25°C
-2%
8
+2%
MHz
5V
Ta=25°C
-2%
12
+2%
MHz
3V/5V
Ta=0°C~70°C
-5%
4
+5%
MHz
3V/5V
Ta=0°C~70°C
-4%
8
+4%
MHz
5V
Ta=0°C~70°C
-5%
12
+3%
MHz
2.2V~3.6V Ta=0°C~70°C
-7%
4
+7%
MHz
3.0V~5.5V Ta=0°C~70°C
-5%
4
+9%
MHz
2.2V~3.6V Ta=0°C~70°C
-6%
8
+4%
MHz
3.0V~5.5V Ta=0°C~70°C
-4%
8
+9%
MHz
3.0V~5.5V Ta=0°C~70°C
-6%
12
+7%
MHz
2.2V~3.6V Ta=-40°C~85°C
-12%
4
+8%
MHz
3.0V~5.5V Ta=-40°C~85°C
-10%
4
+9%
MHz
2.2V~3.6V Ta=-40°C~85°C
-15%
8
+4%
MHz
3.0V~5.5V Ta=-40°C~85°C
-8%
8
+9%
MHz
3.0V~5.5V Ta=-40°C~85°C
-12%
12
+7%
MHz
-10%
32
+10%
kHz
-30%
32
+60%
kHz
μs
5V
Ta = 25°C
fLIRC
System Clock (LIRC)
tTIMER
TCKn Input Pin Pulse Width
—
—
0.3
—
—
tINT
Interrupt Pulse Width
—
—
10
—
—
μs
System Start-up Timer Period
(Wake-up from HALT,
fSYS off at HALT state)
—
fSYS = HXT
128
—
—
tSYS
—
fSYS = HIRC
16
—
—
tSYS
—
fSYS = LIRC
2
—
—
tSYS
System Start-up Timer Period
(Wake-up from HALT,
fSYS on at HALT state)
—
—
2
—
—
tSYS
System Reset Delay Time
(Power On Reset)
—
—
25
50
100
ms
System Reset Delay Time
(Any Reset except Power On Reset)
—
—
8.3
16.7
33.3
ms
tEERD
EEPROM Read Time
—
—
—
4
tSYS
tEEWR
EEPROM Write Time
—
1
2
4
ms
tSST
tRSTD
2.2V~5.5V Ta = -40°C to 85°C
fSYS = 20MHz
—
Note: 1. tSYS=1/fSYS
2. To maintain the accuracy of the internal HIRC oscillator frequency, a 0.1μF decoupling capacitor should
be connected between VDD and VSS and located as close to the device as possible.
Rev. 1.30
16
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
LVD and LVR Electrical Characteristics
Ta=25°C
Symbol
Parameter
Test Conditions
VDD
VLVR2
Min.
LVR Enable, VLVR = 2.1V
VLVR1
VLVR3
Conditions
Low Voltage Reset Voltage
—
LVR Enable, VLVR = 2.55V
LVR Enable, VLVR = 3.15V
Typ.
Max.
2.1
-5%×
Typ.
2.55
3.15
Unit
V
+5%×
Typ.
V
V
VLVR4
LVR Enable, VLVR = 3.8V
3.8
V
VLVD1
LVDEN = 1, VLVD = 2.0V
2.0
V
VLVD2
LVDEN = 1, VLVD = 2.2V
2.2
V
VLVD3
LVDEN = 1, VLVD = 2.4V
2.4
V
VLVD4
VLVD5
Low Voltage Detector Voltage
—
LVDEN = 1, VLVD = 2.7V
LVDEN = 1, VLVD = 3.0V
-5%×
Typ.
2.7
3.0
+5%×
Typ.
V
V
VLVD6
LVDEN = 1, VLVD = 3.3V
3.3
V
VLVD7
LVDEN = 1, VLVD = 3.6V
3.6
V
VLVD8
LVDEN = 1, VLVD = 4.0V
4.0
V
3V
ILVR
Additional Power Consumption
ILVD
Additional Power Consumption
if LVD is used
5V
—
5V
3V
LVD disable à LVD enable
(LVR enable)
—
30
45
μA
—
60
90
μA
—
30
45
μA
—
60
90
μA
tLVR
Low Voltage Width to Reset
—
—
120
240
480
μs
tLVD
Low Voltage Width to Interrupt
—
—
20
45
90
μs
tLVDS
LVDO stable time
—
For LVR enable, LVD offàon
15
—
—
μs
—
For LVR disable, LVD offàon
15
—
—
μs
tSRESET
Software Reset Width to Reset
—
—
45
90
120
μs
Rev. 1.30
17
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
A/D Converter Characteristics
Ta=25°C
Symbol
Parameter
Test Conditions
VDD
Conditions
Min.
Typ.
Max.
Unit
0
—
VREF
V
VADI
A/D Converter Input Voltage
—
—
VREF
A/D Converter Reference Voltage
—
—
2
—
VDD
V
VBG
Reference Voltage with Buffer Voltage
—
—
-3%
1.25
+3%
V
DNL1
Differential Non-linearity
VREF=AVDD=VDD,
tADCK =0.5μs, Ta=25°C
-3
—
+3
LSB
VREF=AVDD=VDD,
tADCK =0.5μs,
Ta=-40°C~85°C
-4
—
+4
LSB
VREF=AVDD=VDD,
tADC =0.5μs, Ta=25°C
-4
—
+4
LSB
VREF=AVDD=VDD
tADCK =0.5μs,
Ta=-40°C~85°C
-8
—
+8
LSB
—
0.9
1.35
mA
2.7V
3V
5V
2.7V
DNL2
Differential Non-linearity
3V
5V
2.7V
INL1
Integral Non-linearity
3V
5V
2.7V
INL2
Integral Non-linearity
3V
5V
IADC
Additional Power Consumption if A/D
Converter is Used
3V
No load, tADCK =0.5μs
5V
No load, tADCK =0.5μs
tADCK
A/D Converter Clock Period
—
tADC
A/D Conversion Time
(Include Sample and Hold Time)
—
tADS
A/D Converter Sampling Time
—
tON2ST
A/D Converter On-to-Start Time
tBGS
VBG Turn on Stable Time
Rev. 1.30
—
1.2
1.8
mA
0.5
─
10
μs
—
16
—
tADCK
—
—
4
—
tADCK
—
—
2
—
—
μs
—
—
200
—
—
μs
—
12 bit A/D Converter
18
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Power-on Reset 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 Raising Rate to
Ensure Power-on Reset
—
—
0.035
—
—
V/ms
tPOR
Minimum Time for VDD
Stays at VPOR to Ensure
Power-on Reset
—
—
1
—
—
ms
System Architecture
A key factor in the high-performance features of the Holtek range of microcontrollers is attributed
to their internal system architecture. The range of devices take advantage of the usual features found
within RISC microcontrollers providing increased speed of operation and enhanced 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, 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.
Rev. 1.30
19
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D


   
   
System Clocking and Pipelining
  
    
 Instruction Fetching
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.
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.
Rev. 1.30
20
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Program Counter
Device
High Byte
Low Byte (PCL Register)
HT66F24D
PC10~PC8
PCL7~PCL0
HT66F25D
PC11~PC8
PCL7~PCL0
HT66F26D
PC12~PC8
PCL7~PCL0
Program Counter
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.
Stack
This is a special part of the memory which is used to save the contents of the Program Counter only.
The stack has multiple levels depending upon the device and 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
Rev. 1.30
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
P ro g ra m
M e m o ry
S ta c k L e v e l 3
o f S ta c k
S ta c k L e v e l N
Device
Stack Levels
HT66F24D
8
HT66F25D
8
HT66F26D
8
21
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Arithmetic and Logic Unit – ALU
The arithmetic-logic unit or ALU is a critical area of the that carries out arithmetic and logic
operations of the instruction set. Connected to the main 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
• Logic operations: AND, OR, XOR, , ORM, XORM, CPL, CPLA
• Rotation RRA, RR, RRCA, RRC, RLA, RL, RLCA, RLC
• Increment and Decrement INCA, INC, DECA, DEC
• Branch decision, JMP, SZ, SZA, SNZ, SIZ, SDZ, SIZA, SDZA, CALL, RET, RETI
Flash Program Memory
The Program Memory is the location where the user code or program is stored. For this device
series 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, these Flash devices offer 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 2Kx16 bits to 8Kx16 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
HT66F24D
2K × 16
HT66F25D
4K × 16
HT66F26D
8K × 16
Program Memory Structure
Rev. 1.30
22
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
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.
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 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 “700H” which refers to the start
address of the last page within the 2K Program Memory of the HT66F24D 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 "706H" or 6 locations after the start of the last page.
Note that the value for the table pointer is referenced to the first address of the present page if the
"TABRD [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 "TABRD [m]" instruction is
executed.
Because the TBLH register is a read-only register and cannot 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.
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HT66F24D/HT66F25D/HT66F26D
Table Read Program Example
tempreg1db ?
tempreg2db ?
:
:
mov a,06h mov tblp,a mov a,07h movtbhp,a
:
:
tabrd tempreg1
dec tblp tabrd tempreg2
:
:
org 700h ; temporary register #1
; temporary register #2
; initialise low table pointer - note that this address
; is referenced
; initialise high table pointer
; transfers value in table referenced by table pointer data at
; program memory address 706H transferred to tempreg1 and TBLH
;
;
;
;
;
reduce value of table pointer by one
transfers value in table referenced by table pointer data at
program memory address 705H transferred to tempreg2 and TBLH
in this example the data 1AH is transferred to tempreg1 and
data 0FH to register tempreg2
; 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 5-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.
Holtek Writer Pins
MCU Programming Pins
ICPDA
PA0
Programming Serial Data
Pin Description
ICPCK
PA2
Programming Clock
ICPMS
PB0
Programming Mode Select
VDD
VDD
Power Supply
VSS
VSS
Ground
The Program Memory can be programmed serially in-circuit using this 5-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 one line for the reset. The technical details
regarding the in-circuit programming of the devices are beyond the scope of this document and will
be supplied in supplementary literature.
During the programming process the ICPMS pin will be held low by the programmer disabling the
normal operation of the microcontroller and taking control of the PA0 and PA2 I/O pins for data
and clock programming purposes. The user must there take care to ensure that no other outputs are
connected to these two pins.
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HT66F24D/HT66F25D/HT66F26D
W r ite r C o n n e c to r
S ig n a ls
M C U
P r o g r a m m in g
P in s
V D D
V D D
IC P M S
P B 0
IC P D A
P A 0
IC P C K
P A 2
V S S
V S S
*
*
*
T o o th e r C ir c u it
Note: * may be resistor or capacitor. The resistance of * must be greater than 1kΩ or the capacitance of * must be less than 1nF.
On-Chip Debug Support – OCDS
There is an EV chip named HT66V26D which is used to emulate the HT66F2xD series of devices.
The HT66V26D device also provides the “On-Chip Debug” function to debug the HT66F2xD
series of devices during development process. The devices, HT66F2xD and HT66V26D, are almost
functional compatible except the “On-Chip Debug” function and package types. Users can use
the HT66V26D device to emulate the HT66F2xD series of devices behaviors 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 HT66V26D EV chip for debugging, the corresponding pin functions shared with
the OCDSDA and OCDSCK pins in the HT66F2xD series of devices will have no effect in the
HT66V26D EV chip. However, the two OCDS pins which are pin-shared with the ICP programming
pins are still used as the Flash Memory programming pins for ICP. For more detailed OCDS
information, refer to the corresponding document named “Holtek e-Link for 8-bit MCU OCDS
User’s Guide”.
Rev. 1.30
Holtek e-Link Pins
EV Chip Pins
OCDSDA
OCDSDA
On-Chip Debug Support Data/Address input/output
Pin Description
OCDSCK
OCDSCK
On-Chip Debug Support Clock input
VDD
VDD
Power Supply
GND
VSS
Ground
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
RAM Data Memory
The Data Memory is a volatile area of 8-bit wide RAM internal memory and is the location where
temporary information is stored.
Structure
Divided into two sections, the first of these is an area of RAM, known as the Special Function Data
Memory. Here are located registers which 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 known as the General Purpose Data Memory, which is reserved
for general purpose use. All locations within this area are read and write accessible under program
control.
The overall Data Memory is subdivided into up to three banks, the structure of which depends
upon the device chosen. The Special Purpose Data Memory registers are accessible in all banks.
Switching between the different Data Memory banks is achieved by setting the Bank Pointer to the
correct value. 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 40H or 80H for
different chosen device.
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HT66F24D/HT66F25D/HT66F26D
Bank 0
00H
00H
Bank 0
Spe�ial Pu�pose
Data �emo�y
Spe�ial Pu�pose
Data �emo�y
3FH
40H
3FH
40H
EEC in bank 1
EEC in bank 1
Gene�al Pu�pose
Data �emo�y
9FH
Gene�al Pu�pose
Data �emo�y
Bank 0
HT66F24D
Data Memory Structure
Bank 0
00H
FFH
Bank 0
HT66F25D
Data Memory Structure
Spe�ial Pu�pose
Data �emo�y
EEC in bank 1
7FH
80H
Gene�al Pu�pose
Data �emo�y
FFH
Bank 0
Bank 1
Bank �
HT66F26D
Data Memory Structure
RAM Data Memory Structure
Device
Capacity
Bank : Address
HT66F24D
96 × 8
Bank 0 : 40H ~ 9FH
HT66F25D
192 × 8
Bank 0 : 40H ~ FFH
HT66F26D
384 × 8
Bank 0 : 80H ~ FFH
Bank 1 : 80H ~ FFH
Bank 2 : 80H ~ FFH
General Purpose Data Memory Structure
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HT66F24D/HT66F25D/HT66F26D
Bank 0
Bank 1
Bank 0
Bank 1
00H
IAR0
��H
01H
�P0
0�H
IAR1
�4H
��H
03H
�P1
�6H
T�PC0
04H
BP
�7H
Unused
0�H
ACC
�8H
ADRL
Unused
PR�0
06H
PCL
�9H
ADRH
07H
TBLP
�AH
ADCR0
08H
TBLH
�BH
ADCR1
09H
TBHP
�CH
ACERL
0AH
STATUS
�DH
Unused
0BH
S�OD
�EH
T�0C0
0CH
LVDC
�FH
T�0C1
0DH
INTEG
30H
T�0DL
0EH
WDTC
31H
T�0DH
0FH
TBC
3�H
T�0AL
10H
INTC0
33H
T�0AH
11H
INTC1
34H
T�1C0
1�H
INTC�
3�H
T�1C1
13H
�FI0
36H
Unused
14H
�FI1
37H
T�1DL
1�H
�FI�
38H
T�1DH
16H
CTRL
39H
T�1AL
17H
LVRC
T�1AH
18H
PAWU
3AH
3BH
19H
PAPU
1AH
PA
3DH
3EH
1BH
PAC
3FH
1CH
PBPU
40H
1DH
PB
1EH
PBC
1FH
PCPU
�0H
PC
�1H
PCC
Unused
EEA
EED
Data
RA�
EEC
9FH
: Unused� �ead as 00H
HT66F24D Special Purpose Data Memory Structure
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Bank 0 Bank 1
IAR0
��H
01H
�P0
�3H
PD
0�H
IAR1
�4H
PDC
03H
�P1
��H
PR�0
04H
BP
�6H
T�PC0
0�H
ACC
�7H
Unused
00H
Bank 0 Bank 1
PDPU
06H
PCL
�8H
ADRL
07H
TBLP
�9H
ADRH
08H
TBLH
�AH
ADCR0
09H
TBHP
�BH
ADCR1
0AH
STATUS
�CH
ACERL
0BH
S�OD
�DH
Unused
0CH
LVDC
�EH
T�0C0
0DH
INTEG
�FH
T�0C1
0EH
WDTC
30H
T�0DL
0FH
TBC
31H
T�0DH
10H
INTC0
3�H
T�0AL
11H
INTC1
33H
T�0AH
1�H
INTC�
34H
T�1C0
13H
�FI0
3�H
T�1C1
14H
�FI1
36H
T�1C�
1�H
�FI�
37H
T�1DL
16H
CTRL
38H
T�1DH
17H
LVRC
39H
T�1AL
18H
PAWU
3AH
T�1AH
19H
PAPU
3BH
T�1BL
1AH
PA
3CH
T�1BH
1BH
PAC
3DH
Unused
1CH
PBPU
3EH
EEA
1DH
PB
3FH
EED
1EH
PBC
40H
1FH
PCPU
�0H
PC
�1H
PCC
FFH
Data
RA�
EEC
: Unused� �ead as 00H
HT66F25D Special Purpose Data Memory Structure
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HT66F24D/HT66F25D/HT66F26D
00H
Bank 0~�
IAR0
1CH
Bank 0~�
PBPU
34H
Bank 0� � Bank 1
T�1C0
01H
�P0
1DH
PB
3�H
T�1C1
0�H
IAR1
1EH
PBC
36H
T�1C�
03H
�P1
1FH
PCPU
37H
T�1DL
04H
BP
�0H
PC
38H
T�1DH
0�H
ACC
�1H
PCC
39H
T�1AL
06H
PCL
��H
PDPU
3AH
T�1AH
07H
TBLP
�3H
PD
3BH
T�1BL
08H
TBLH
�4H
PDC
3CH
T�1BH
09H
TBHP
��H
PR�0
3DH
Unused
0AH
STATUS
�6H
T�PC0
3EH
EEA
0BH
S�OD
�7H
T�PC1
3FH
EED
0CH
LVDC
�8H
ADRL
40H
0DH
INTEG
�9H
ADRH
41H
T��C0
EEC
0EH
WDTC
�AH
ADCR0
4�H
T��C1
0FH
TBC
�BH
ADCR1
43H
Unused
10H
INTC0
�CH
ACERL
44H
T��DL
11H
INTC1
�DH
�FI3
4�H
T��DH
1�H
INTC�
�EH
T�0C0
46H
T��AL
13H
�FI0
�FH
T�0C1
47H
T��AH
14H
�FI1
30H
T�0DL
48H
1�H
�FI�
31H
T�0DH
16H
CTRL
3�H
T�0AL
17H
LVDC
33H
T�0AH
18H
PAWU
19H
PAPU
1AH
PA
1BH
PAC
Unused
FFH
: Unused� �ead as 00H
HT66F26D Special Purpose Data Memory Structure
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Special Function Register Description
Most of the Special Function Register details will be described in the relevant functional section.
However, several registers require a separate description in this section.
Indirect Addressing Registers – IAR0, IAR1
The Indirect Addressing Registers, IAR0 and IAR1, 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 and IAR1 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 or MP1. 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, MP1
Two Memory Pointers, known as MP0 and MP1 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 Bank 0, while MP1 and IAR1 are used to
access data from all banks according to BP register. Direct Addressing can only be used with Bank
0 while all other Banks must be addressed indirectly using MP1 and IAR1. The following example
shows how to clear a section of four Data Memory locations already defined as locations adres1 to
adres4.
Indirect Addressing Program Example
data .section data
adres1 db?
adres2 db ?
adres3 db ?
adres4 db?
block db?
code .section at 0 code
org 00h
begin:
mov a,04h
; setup size of block
mov block,a
mov a, offset adres1 ; Accumulator loaded with first RAM address
mov mp0, a ; setup memory pointer with first RAM address
loop:
clr IAR0 ; clear the data at address defined by MP0
inc mp0 ; increment memory pointer
sdz block ; check if last memory location has been cleared
jmploop
continue:
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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HT66F24D/HT66F25D/HT66F26D
Bank Pointer – BP
Selecting the required Data Memory area is achieved using the Bank Pointer. The Bank Pointer BP
bits are used to select Data Memory Banks 0~2. The Data Memory is initialised to Bank 0 after a
reset, except for a WDT time-out reset in the Power down Mode, in which case, the Data Memory
bank remains unaffected. It should be noted that the Special Function Data Memory is not affected
by the bank selection, which means that the Special Function Registers can be accessed from
within any bank. Directly addressing the Data Memory will always result in Bank 0 being accessed
irrespective of the value of the Bank Pointer. Accessing data from banks other than Bank 0 must be
implemented using indirect addressing.
BP Register – HT66F24D/HT66F25D
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
—
—
—
DMBP0
R/W
—
—
—
—
—
—
—
R/W
POR
—
—
—
—
—
—
—
0
Bit 7~1
unimplemented, read as “0”
Bit 0
DMBP0: Data Memory Bank Pointer
0: Bank 0
1: Bank 1
BP Register – HT66F26D
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
—
—
DMBP1
DMBP0
R/W
—
—
—
—
—
—
R/W
R/W
POR
—
—
—
—
—
—
0
0
Bit 7~1
unimplemented, read as “0”
Bit 0
DMBP1~DMBP0: Data Memory Bank Pointer
00: Bank 0
01: Bank 1
10: Bank 2
11: Reserved
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.
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
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 pointer and indicates 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 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 and C flags generally reflect the status of the latest operations.
• 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.
• 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.
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
STATUS Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
TO
PDF
OV
Z
AC
C
R/W
—
—
R
R
R/W
R/W
R/W
R/W
POR
—
—
0
0
x
x
x
x
Rev. 1.30
“X” unknown
Bit 7, 6
Unimplemented, read as "0"
Bit 5
TO: Watchdog Time-Out flag
0: After power up or executing the "CLR WDT" or "HALT" instruction
1: A watchdog time-out occurred.
Bit 4
PDF: Power down flag
0: After power up or executing the "CLR WDT" instruction
1: By executing the "HALT" instruction
Bit 3
OV: 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 2
Z: 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 1
AC: 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 0
C: 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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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
EEPROM Data Memory
The device contains an area of internal EEPROM Data Memory. EEPROM, which stands for
Electrically Erasable Programmable Read Only Memory, is by its nature a non-volatile form
of re-programmable 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 64x8 bits for this series of devices. 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 Bank 0 and a single control register in Bank 1.
Device
Capacity
Address
HT66F24D
64 × 8
00H ~ 3FH
HT66F25D
64 × 8
00H ~ 3FH
64 × 8
00H ~ 3FH
HT66F26D
EEPROM Data Memory Structure
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 Bank 0, they can be directly accessed in the same was as any other
Special Function Register. The EEC register however, being located in Bank1, cannot be addressed
directly and can only be read from or written to indirectly using the MP1 Memory Pointer and
Indirect Addressing Register, IAR1. Because the EEC control register is located at address 40H in
Bank 1, the MP1 Memory Pointer must first be set to the value 40H and the Bank Pointer register,
BP, set to the value, 01H, before any operations on the EEC register are executed.
EEPROM Register List
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
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
EEA Register
Rev. 1.30
Bit 7~6
“—” Unimplemented, read as 0
Bit 5~0
Data EEPROM address bit 5 ~ bit 0
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
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 7~0
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 7~0
“—” Unimplemented, read as 0
Bit 3
WREN: 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 operation are carried out. Clearing this bit to zero will inhibit Data
EEPROM write operations.
Bit 2
WR: Data 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 1
RDEN: 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 operation are carried out. Clearing this bit to zero will inhibit Data
EEPROM read operations.
Bit 0
RD: Data 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.
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
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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. Note that 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 the Bank Pointer, BP, will be reset to zero, which means that Data
Memory Bank 0 will be selected. As the EEPROM control register is located in Bank 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. However as
the EEPROM is contained within a Multi-function Interrupt, the associated multi-function interrupt
enable bit must also be set. When an EEPROM write cycle ends, the DEF request flag and its
associated multi-function interrupt request flag will both be set. If the global, EEPROM and Multifunction interrupts are enabled and the stack is not full, a jump to the associated Multi-function
Interrupt vector will take place. When the interrupt is serviced only the Multi-function interrupt flag
will be automatically reset, the EEPROM interrupt flag must be manually reset by the application
program. More details can be obtained in the Interrupt section.
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
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Programming Considerations
Care must be taken that data is not inadvertently written to the EEPROM. Protection can be
enhanced 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 1 where
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.
Programming Examples
Reading data from the EEPROM - polling method
MOV A, EEPROM_ADRES
MOV EEA, A
MOV A, 040H
MOV MP1, A
MOV A, 01H
MOV BP, 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 MP1
; MP1 points to EEC register
; setup Bank Pointer
; 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 MP1, A
MOV A, 01H
MOV BP, A
CLR EMI
SET IAR1.3
SET IAR1.2
SET EMI
BACK:
SZ IAR1.2
JMP BACK
CLR IAR1
CLR BP
Rev. 1.30
; user defined address
; user defined data
; setup memory pointer MP1
; MP1 points to EEC register
; setup Bank Pointer
; set WREN bit, enable write operations
; Start Write Cycle - set WR bit - executed immediately
; after set WREN bit
; check for write cycle end
; disable EEPROM read/write
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Enhanced A/D Flash Type MCU with High Current LED Driver
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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. 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 oscillators provide 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.
Type
Name
Freq.
Pins
External High Speed Crystal
HXT
400kHz~12MHz
OSC1/OSC2
Internal High Speed RC
HIRC
4, 8 or 12MHz
—
Internal Low Speed RC
LIRC
32kHz
—
Oscillator Types
System Clock Configurations
There are three system oscillators, two high speed and one low speed oscillators. The high speed
oscillators are the external crystal/ceramic oscillator – HXT and the internal RC oscillator - HIRC.
The low speed oscillator is the internal 32 kHz oscillator – LIRC. 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 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.
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Hig� Speed
Os�illato�
HXT
fH
6-stage P�es�ale�
HIRC
Hig� Speed Os�illato�
Configu�ation Option
fH/�
fH/4
fH/8
fH/16
fH/3�
fH/64
fSYS
fL
LXT
Fast Wake-up f�om SLEEP
�ode o� IDLE �ode Cont�ol
(fo� HXT only)
HLCLK�
CKS�~CKS0 bits
fSUB
LIRC
fSUB Os�illato�
Configu�ation Option
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 inter connecting lines are all
located as close to the MCU as possible.
     Crystal/Resonator Oscillator – HXT
Rev. 1.30
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March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
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 High Speed RC Oscillator – HIRC
The internal RC oscillator is a fully integrated system oscillator requiring no external components.
The internal RC oscillator has three fixed frequencies of either 4MHz, 8MHz or 12MHz. 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 either 3V or
5V and at a temperature of 25°C degrees, the fixed oscillation frequency of 4MHz, 8MHz or 12MHz
will have a tolerance within 2%. Note that if this internal system clock option is selected, as it
requires no external pins for its operation, I/O pins PA6 and PA5 are free for use as normal I/O pins.
Internal 32kHz Oscillator – LIRC
The Internal 32kHz System Oscillator is one of the low frequency oscillator choices, which is
selected via configuration option. It is a fully integrated RC oscillator with a typical frequency of
32 kHz 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 32 kHz 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 the Time Base Interrupts function.
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
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 these devices 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 a high frequency fH or low frequency fSUB source 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 a HXT or HIRC oscillator, selected via a configuration option. The
low speed system clock source can be sourced from internal clock fSUB. If fSUB is selected, then it can
be sourced by the LIRC oscillator. The other choice, which is a divided version of the high speed
system oscillator has a range of fH/2~fH/64. Note that when the system clock source fSYS is switched
to fSUB from fH, the high speed oscillation will stop to conserve the power. Thus there is no fH~fH/64
for peripheral circuit to use.
There is an additional internal clock for the peripheral circuits, the substitute clock, fSUB. The internal
clock is sourced by the LIRC 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. Together with
fSYS/4 it is also used as one of the clock sources for the Time Base interrupt function. The fSUB clock
is also used as a clock source for the TMs.
Hig� Speed
Os�illato�
HXT
fH
6-stage P�es�ale�
HIRC
Hig� Speed Os�illato�
Configu�ation Option
Low Speed
Os�illato�
LXT
fH/�
fH/4
fH/8
fH/16
fH/3�
fH/64
fSYS
fSUB
LIRC
HLCLK�
CKS�~CKS0 bits
Low Speed Os�illato�
Configu�ation Option
fSYS/4
fTB
fSUB
Fast Wake-up f�om
SLEEP o� IDLE �ode
Cont�ol (fo� HXT only)
Time Base
TBCK
fSUB
Rev. 1.30
Wat��dog Time�
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
System Operation Modes
There are six 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 two modes allowing normal operation of the
microcontroller, the NORMAL Mode and SLOW Mode. The remaining four modes, the SLEEP0,
SLEEP1, IDLE0 and IDLE1 Mode are used when the microcontroller CPU is switched off to
conserve power.
Operating Mode
Description
CPU
fSYS
fSUB
NORMAL Mode
On
fH ~ fH/64
On
SLOW Mode
On
fL
On
IDLE0 Mode
Off
Off
On
IDLE1 Mode
Off
On
On
SLEEP0 Mode
Off
Off
Off
SLEEP1 Mode
Off
Off
On
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, either the HXT or HIRC oscillators. The high speed oscillator
will however first be divided by a ratio ranging from 1 to 64, the actual ratio being selected by the
CKS2~CKS0 and HLCLK bits in the SMOD register. Although a high speed oscillator is used,
running the microcontroller at a divided clock ratio reduces the operating current.
SLOW 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. Running
the microcontroller in this mode allows it to run with much lower operating currents. In the SLOW
Mode, the fH is off.
SLEEP0 Mode
The SLEEP Mode is entered when a HALT instruction is executed and the IDLEN bit in the SMOD
register is low. In the SLEEP0 mode the CPU will be stopped, and the fSUB clock will be stopped
too, and the Watchdog Timer function is disabled. In this mode, the LVDEN is must set to 0. If the
LVDEN is set to 1, it won’t enter the SLEEP0 Mode.
SLEEP1 Mode
The SLEEP Mode is entered when a HALT instruction is executed and the IDLEN bit in the SMOD
register is low. In the SLEEP1 mode the CPU will be stopped. However, the fS clock will continue
to operate if the LVDEN is set to 1 or the Watchdog Timer function is enabled since its clock source
comes from the LIRC oscillator.
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
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 while the fSUB clock will be on.
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 while the fSUB clock will be on.
Control Register
The corresponding system control registers, SMOD and CTRL, are used for overall control of the
internal clocks within the device.
SMOD Register
Rev. 1.30
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 when HLCLK is 0
000: fSUB (fLIRC)
001: fSUB (fLIRC)
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, a divided version of the
high speed system oscillator can also be chosen as the system clock source.
Bit 4
FSTEN: 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.
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Enhanced A/D Flash Type MCU with High Current LED Driver
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Bit 3
LTO: 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 or a wake-up has occurred. The flag
will be low when in the SLEEP0 Mode but after a wake-up has occurred, the flag will
change to a high level after 1~2 clock cycles if the LIRC oscillator is used.
Bit 2
HTO: 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 or IDLE0 Mode but after 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.
Bit 1
IDLEN: 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 as the
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 0
HLCLK: System clock selection
0: fH/2 ~ fH/64 or fSUB
1: fH
This bit is used to select if the fH clock or the fH/2 ~ fH/64 or fSUB 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 fSUB clock will be selected. When system clock switches from the fH clock to
the fSUB clock, 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
—
—
—
—
x
0
0
Bit 7
Rev. 1.30
FSYSON: fSYS Control in IDLE Mode
0: Disable
1: Enable
Bit 6~3
“—”: Unimplemented, read as 0
Bit 2
LVRF: 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 0 by the application program.
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Enhanced A/D Flash Type MCU with High Current LED Driver
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Bit 1
LRF: LVR Control 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
0 by the application program.
Bit 0
WRF: WDT Control register software reset flag
0: Not occur
1: Occurred
This bit is set to 1 by the WDT Control register software reset and cleared by the
application program. Note that this bit can only be cleared to 0 by the application
program.
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, namely the LIRC oscillator, to act as a temporary clock to first drive
the system until the original system oscillator has stabilised. As the clock source for the Fast Wakeup function is fSUB, the Fast Wake-up function is only available in the SLEEP1 and IDLE0 modes.
When the device is woken up from the SLEEP0 mode, the Fast Wake-up function has no effect
because the fSUB clock is stopped. 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 the Fast Wake-up function
is enabled, then it will take one to two tSUB clock cycles of the LIRC oscillator 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.
If the HIRC oscillators or LIRC oscillator is used as the system oscillator then it will take 15~16
clock cycles of the HIRC or 1~2 cycles of the LIRC oscillator 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
(SLEEP0 Mode)
Wake-up Time
(SLEEP1 Mode)
Wake-up Time
(IDLE0 Mode)
Wake-up Time
(IDLE1 Mode)
0
128 HXT cycles
128 HXT cycles
1
128 HXT cycles
1~2 fSUB cycles
(System runs first with fSUB for 128 HXT
1~2 HXT cycles
cycles and then switches over to run with the
HXT clock)
HIRC
X
15~16 HIRC cycles
15~16 HIRC cycles
1~2 HIRC cycles
LIRC
X
1~2 LIRC cycles
1~2 LIRC cycles
1~2 LIRC cycles
HXT
Wake-up Times
1~2 HXT cycles
“X”: don’t care
Note that if the Watchdog Timer is disabled, which means that the LIRC oscillator is off, then there
will be no Fast Wake-up function available when the device wakes-up from the SLEEP0 Mode.
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
­ €    
­ €    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 fSUB. If the clock is from the fSUB, 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.
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
NORMAL Mode to SLOW 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 SLOW Mode by set the HLCLK
bit to 0 and set the CKS2~CKS0 bits to 000B or 001B 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 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.
  
   ­   ­       ­   ­  €‚ ƒ    ­   ­  €‚ ƒ    ­   ­  Rev. 1.30
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March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
SLOW Mode to NORMAL Mode Switching
In SLOW Mode the system uses the LIRC 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
or HLCLK bit is 0 but CKS2~CKS0 is set to 010B, 011B, 100B, 101B, 110B or 111B. 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.
  
     ­          ­   € ‚      ­   € ‚      ­   Entering the SLEEP0 Mode
There is only one way for the device to enter the SLEEP0 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 and LVD both off. When this instruction is executed under the conditions described above, the
following will occur:
• The system clock, WDT clock and Time Base clock will be stopped 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 stopped.
• 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.
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Entering the SLEEP1 Mode
There is only one way for the device to enter the SLEEP1 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
or LVD 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
• The Data Memory contents and registers will maintain their present condition.
• The WDT will be cleared and resume counting as the WDT function is enabled.
• 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.
In SLOW Mode the system uses the LIRC 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
or HLCLK bit is 0 but CKS2~CKS0 is set to 010B, 011B, 100B, 101B, 110B or 111B. 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.
• 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 the 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
while the fSUB clock and time base clock which is derived from 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 if the WDT function is enabled.
• 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 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 the CTRL register equal to 1. When this instruction is executed under the conditions
described above, the following will occur:
• The system clock, Time Base clock and fSUB clock 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 if the WDT function is enabled.
• 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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Enhanced A/D Flash Type MCU with High Current LED Driver
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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. Also note that additional
standby current will also be required if the configuration option has enabled the LIRC oscillator.
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. If a WDT
time-out occurs, it will set TO flag and cause a wake-up that only resets the Program Counter and
Stack Pointer, the other flags remain in their original status.
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 HXT oscillator use the same SST counter. For example, if the system is woken up from the
SLEEP0 Mode and the HXT oscillator need to start-up from an off state.
If the device is woken up from the SLEEP0 Mode to the NORMAL Mode, the high speed system
oscillator needs an SST period. The device will execute first instruction after the HTO bit is set to 1.
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
If the device is woken up from the SLEEP1 Mode to NORMAL Mode, and the system clock source
is from the HXT oscillator and the FSTEN bit is set to 1, the system clock can first be switched to
the LIRC 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 the high speed clock fH to low speed clock fSUB, 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 internal clock, fS, which is source from the
LIRC oscillator. The LIRC internal oscillator has an approximate frequency of 32kHz at a supply
voltage of 5V. However, it should be noted that this specified internal clock period can vary with
VDD, temperature and process variations. 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/disable
operation. This register together with several configuration options control the overall operation of
the Watchdog Timer.
WDTC Register
Rev. 1.30
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
If the WDT configuration option is “always enable”:
10101 or 01010: Enabled
Other: Reset MCU
If the WDT configuration option is “controlled by the WDT control register”:
10101: Disabled
01010: Enabled
Other: Reset MCU
When these bits are changed by the environmental noise to reset the microcontroller,
the reset operation will be activated after 2~3 LIRC clock cycles and the WRF bit in
the CTRL register will be set to 1.
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Enhanced A/D Flash Type MCU with High Current LED Driver
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WS2~WS0: WDT Time-out period selection
000: 28/fS
001: 210/fS
010: 212/fS
011: 214/fS
100: 215/fS
101: 216/fS
110: 217/fS
111: 218/fS
Bit 2~0
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
—
—
—
—
x
0
Bit 7
FSYSON: fSYS Control in IDLE Mode
Describe elsewhere.
0
“x”: unknown
Bit 6~3
“—”: Unimplemented, read as 0
Bit 2
LVRF: LVR function reset flag
Describe elsewhere.
Bit 1
LRF: LVR Control register software reset flag
Describe elsewhere.
Bit 0
WRF: WDT Control register software reset flag
0: Not occur
1: Occurred
This bit is set to 1 by the WDT Control register software reset and cleared by the
application program. Note that this bit can only be cleared to 0 by the application
program.
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, these clear instructions will not be executed in
the correct manner, in which case the Watchdog Timer will overflow and reset the device. Some
of the Watchdog Timer options, such as always on select and clear instruction type are selected
using configuration options. With regard to the Watchdog Timer enable/disable function, there
are also five bits, WE4~WE0, in the WDTC register to offer additional enable/disable and reset
control of the Watchdog Timer. If the WDT configuration option is determined that the WDT
function is always enabled, the WE4~WE0 bits still have effects on the WDT function. When the
WE4~WE0 bits value is equal to 01010B or 10101B, the WDT function is enabled. However, if the
WE4~WE0 bits are changed to any other values except 01010B and 10101B, which is caused by
the environmental noise, it will reset the microcontroller after 2~3 LIRC clock cycles. If the WDT
configuration option is determined that the WDT function is controlled by the WDT control register,
the WE4~WE0 values can determine which mode the WDT operates in. The WDT function will be
disabled when the WE4~WE0 bits are set to a value of 10101B. The WDT function will be enabled
if the WE4~WE0 bits value is equal to 01010B. If the WE4~WE0 bits are set to any other values by
the environmental noise, except 01010B and 10101B, it will reset the device after 2~3 LIRC clock
cycles. After power on these bits will have the value of 01010B.
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Watchdog Timer Enable/Disable Control
WDT Configuration Option
WE4 ~ WE0 Bits
Always Enable
Controlled by WDT Control Register
WDT Function
01010B or 10101B
Enable
Any other value
Reset MCU
10101B
Disable
01010B
Enable
Any other value
Reset MCU
“x”: don’t care.
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 certain value except 01010B and 10101B written into the
WE4~WE0 bit filed, 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
second for the 218 division ratio, and a minimum timeout of 7.8ms for the 28 division ration.
WDTC Registe�
WE4~WE0 bits
Reset �CU
CLR
"CLR WDT" Inst�u�tion
fSUB
fS
8-stage Divide�
WS�~WS0
(fS/�8 ~ fS/�18)
fS/�8
WDT P�es�ale�
WDT Time-out
(�8/fS ~ �18/fS)
8-to-1 �UX
Watchdog timer
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.
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Reset Functions
There are five 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.
Power-On Reset Timing Chart
Note: tRSTD is power-on delay, typical time=50ms
Low Voltage Reset – LVR
The microcontroller contains a low voltage reset circuit in order to monitor the supply voltage of the
device. The LVR function is always enabled with a specific LVR voltage VLVR. 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 to 1. For a valid LVR signal, a low supply voltage, i.e., a voltage in the range between
0.9V~VLVR must exist for a time greater than that specified by tLVR in the A.C. characteristics. If the
low supply 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 value can be selected by the LVS 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 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.
Rev. 1.30
Low Voltage Reset Timing Chart
Note: tRSTD is power-on delay, typical time=16.7ms
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Enhanced A/D Flash Type MCU with High Current LED Driver
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• 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/W
R/W
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
Any other value: Generates 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 clock cycles. In this situation the register contents will
remain the same after such a reset occurs.
Any register value, other than the four defined LVR values above, will also result in
the generation of an MCU reset. The reset operation will be activated after 2~3 LIRC
clock cycles. However in this situation the register contents will be reset to the POR
value.
• 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
—
—
—
—
x
0
0
Bit 7
Rev. 1.30
FSYSON: fSYS Control in IDLE Mode
Describe elsewhere.
Bit 6~3
“—”: Unimplemented, read as 0
Bit 2
LVRF: 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 0 by the application program.
Bit 1
LRF: LVR Control 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
0 by the application program.
Bit 0
WRF: WDT Control register software reset flag
Describe elsewhere.
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Enhanced A/D Flash Type MCU with High Current LED Driver
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Watchdog Time-out Reset during Normal Operation
The Watchdog time-out Reset during normal operation will perform a full reset and also the
Watchdog time-out flag TO will be set to “1”.
WDT Time-out Reset during Normal Operation Timing Chart
Note: tRSTD is power-on delay, typical time=16.7ms
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.
WDT Time-out Reset during SLEEP or IDLE Timing Chart
Note: The tSST is 15~16 clock cycles if the system clock source is provided by HIRC.
The SST is 128 clock cycles for HXT. The SST is 1~2 clock cycles for LIRC.
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
Rev. 1.30
Condition After Power-on Reset
Program Counter
Reset to zero
Interrupts
All interrupt will be disabled
WDT, Time Base
Clear after reset, WDT begins counting
Timer Modules
Timer Counter will be turned off
Input/Output Ports
I/O ports will be setup as inputs and AN0~AN7 as A/D input pins
Stack Pointer
Stack Pointer will point to the top of the stack
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Enhanced A/D Flash Type MCU with High Current LED Driver
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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.
HT66F24D
Rev. 1.30
Register
Power On Reset
LVR Reset
WDT Time-out
(Normal Operation)
WDT Time-out
(IDLE)
MP0
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
MP1
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
BP
---- ---0
---- ---0
---- ---0
---- ---u
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
---- -xxx
---- -uuu
---- -uuu
---- -uuu
STATUS
--00 xxxx
--uu uuuu
--1u uuuu
- - 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
LVDC
--00 -000
--00 -000
--00 -000
--uu -uuu
LVRC
0101 0101
uuuu uuuu
0101 0101
uuuu uuuu
CTRL
0--- -x00
0--- -100
0--- -000
u--- -uuu
INTEG
---- 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 - 111
0 0 11 - 111
0 0 11 - 111
uuuu -uuu
INTC0
-000 0000
-000 0000
-000 0000
-uuu uuuu
INTC1
0000 0000
0000 0000
0000 0000
uuuu uuuu
INTC2
---0 ---0
---0 ---0
---0 ---0
---u ---u
MFI0
--00 --00
--00 --00
--00 --00
--uu --uu
MFI1
--00 --00
--00 --00
--00 --00
--uu --uu
MFI2
--00 --00
--00 --00
--00 --00
--uu --uu
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
--00 0000
--00 0000
--00 0000
--uu uuuu
PB
- - 11 1111
- - 11 1111
- - 11 1111
--uu uuuu
PBC
- - 11 1111
- - 11 1111
- - 11 1111
--uu uuuu
uuuu uuuu
PCPU
0000 0000
0000 0000
0000 0000
PC
1111 1111
1111 1111
1111 1111
uuuu uuuu
PCC
1111 1111
1111 1111
1111 1111
uuuu uuuu
PRM0
0000 ----
0000 ----
0000 ----
uuuu ----
TMPC0
--00 0000
--00 0000
--00 0000
--uu 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
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
58
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Register
Power On Reset
LVR Reset
WDT Time-out
(Normal Operation)
WDT Time-out
(IDLE)
ADCR1
00-0 -000
00-0 -000
00-0 -000
uu-u -uuu
ACERL
1111 1111
1111 1111
1111 1111
uuuu uuuu
TM0C0
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM0C1
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM0DL
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM0DH
---- --00
---- --00
---- --00
---- --uu
TM0AL
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM0AH
---- --00
---- --00
---- --00
---- --uu
TM1C0
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM1C1
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM1DL
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM1DH
---- --00
---- --00
---- --00
---- --uu
TM1AL
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM1AH
---- --00
---- --00
---- --00
---- --uu
Note: “u” stands for unchanged
“x” stands for “unknown”
“-“ stands for unimplemented
Rev. 1.30
59
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
HT66F25D
Rev. 1.30
Register
Power On Reset
LVR Reset
WDT Time-out
(Normal Operation)
WDT Time-out
(IDLE)
MP0
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
MP1
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
BP
---- ---0
---- ---0
---- ---0
---- ---u
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
---- xxxx
---- uuuu
---- uuuu
---- uuuu
STATUS
--00 xxxx
--uu uuuu
--1u uuuu
- - 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
LVDC
--00 -000
--00 -000
--00 -000
--uu -uuu
LVRC
0101 0101
uuuu uuuu
0101 0101
uuuu uuuu
CTRL
0--- -x00
0--- -100
0--- -000
u--- -uuu
INTEG
---- 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
uuuu -uuu
TBC
0 0 11 - 111
0 0 11 - 111
0 0 11 - 111
INTC0
-000 0000
-000 0000
-000 0000
-uuu uuuu
INTC1
0000 0000
0000 0000
0000 0000
uuuu uuuu
INTC2
---0 ---0
---0 ---0
---0 ---0
---u ---u
MFI0
--00 --00
--00 --00
--00 --00
--uu --uu
MFI1
-000 -000
-000 -000
-000 -000
-uuu -uuu
MFI2
--00 --00
--00 --00
--00 --00
--uu --uu
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 uuuu
PB
1111 1111
1111 1111
1111 1111
uuuu uuuu
PBC
1111 1111
1111 1111
1111 1111
uuuu uuuu
uuuu uuuu
PCPU
0000 0000
0000 0000
0000 0000
PC
1111 1111
1111 1111
1111 1111
uuuu uuuu
PCC
1111 1111
1111 1111
1111 1111
uuuu uuuu
PDPU
---- --00
---- --00
---- --00
---- --uu
PD
---- --11
---- --11
---- --11
---- --uu
PDC
---- --11
---- --11
---- --11
---- --uu
PRM0
0000 ----
0000 ----
0000 ----
uuuu ----
TMPC0
0000 0000
0000 0000
0000 0000
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
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
00-0 -000
00-0 -000
00-0 -000
uu-u -uuu
60
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Register
Power On Reset
LVR Reset
WDT Time-out
(Normal Operation)
WDT Time-out
(IDLE)
ACERL
1111 1111
1111 1111
1111 1111
uuuu uuuu
TM0C0
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM0C1
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM0DL
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM0DH
---- --00
---- --00
---- --00
---- --uu
TM0AL
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM0AH
---- --00
---- --00
---- --00
---- --uu
TM1C0
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM1C1
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM1C2
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM1DL
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM1DH
---- --00
---- --00
---- --00
---- --uu
TM1AL
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM1AH
---- --00
---- --00
---- --00
---- --uu
TM1BL
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM1BH
---- --00
---- --00
---- --00
---- --uu
Note: “u” stands for unchanged
“x” stands for “unknown”
“-“ stands for unimplemented
Rev. 1.30
61
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
HT66F26D
Rev. 1.30
Register
Power On Reset
LVR Reset
WDT Time-out
(Normal Operation)
WDT Time-out
(IDLE)
MP0
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
MP1
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
BP
---- --00
---- --00
---- --00
---- ---u
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
--00 xxxx
--uu uuuu
--1u uuuu
- - 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
LVDC
--00 -000
--00 -000
--00 -000
--uu -uuu
LVRC
0101 0101
uuuu uuuu
0101 0101
uuuu uuuu
CTRL
0--- -x00
0--- -100
0--- -000
u--- -uuu
INTEG
---- 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
uuuu -uuu
TBC
0 0 11 - 111
0 0 11 - 111
0 0 11 - 111
INTC0
-000 0000
-000 0000
-000 0000
-uuu uuuu
INTC1
0000 0000
0000 0000
0000 0000
uuuu uuuu
INTC2
---0 ---0
---0 ---0
---0 ---0
---u ---u
MFI0
--00 --00
--00 --00
--00 --00
--uu --uu
MFI1
-000 -000
-000 -000
-000 -000
-uuu -uuu
MFI2
--00 --00
--00 --00
--00 --00
--uu --uu
MFI3
--00 --00
--00 --00
--00 --00
--uu --uu
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 uuuu
PB
1111 1111
1111 1111
1111 1111
uuuu uuuu
PBC
1111 1111
1111 1111
1111 1111
uuuu uuuu
uuuu uuuu
PCPU
0000 0000
0000 0000
0000 0000
PC
1111 1111
1111 1111
1111 1111
uuuu uuuu
PCC
1111 1111
1111 1111
1111 1111
uuuu uuuu
PDPU
---- --00
---- --00
---- --00
---- --uu
PD
---- --11
---- --11
---- --11
---- --uu
PDC
---- --11
---- --11
---- --11
---- --uu
PRM0
0000 ----
0000 ----
0000 ----
uuuu ----
TMPC0
0000 0000
0000 0000
0000 0000
uuuu uuuu
TMPC1
---- -000
---- -000
---- -000
---- -uuu
ADRL
(ADRFS=0)
xxxx ----
xxxx ----
xxxx ----
uuuu ----
ADRL
(ADRFS=1)
xxxx ----
xxxx ----
xxxx ----
uuuu uuuu
ADRH
(ADRFS=0)
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
ADRH
(ADRFS=1)
xxxx xxxx
xxxx xxxx
xxxx xxxx
---- uuuu
62
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Register
Power On Reset
LVR Reset
WDT Time-out
(Normal Operation)
WDT Time-out
(IDLE)
ADCR0
0 11 0 - 0 0 0
0 11 0 - 0 0 0
0 11 0 - 0 0 0
uuuu -uuu
ADCR1
00-0 -000
00-0 -000
00-0 -000
uu-u -uuu
ACERL
1111 1111
1111 1111
1111 1111
uuuu uuuu
TM0C0
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM0C1
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM0DL
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM0DH
---- --00
---- --00
---- --00
---- --uu
TM0AL
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM0AH
---- --00
---- --00
---- --00
---- --uu
TM1C0
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM1C1
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM1DL
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM1DH
---- --00
---- --00
---- --00
---- --uu
TM1AL
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM1AH
---- --00
---- --00
---- --00
---- --uu
TM1BL
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM1BH
---- --00
---- --00
---- --00
---- --uu
TM2C0
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM2C1
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM2DL
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM2DH
---- --00
---- --00
---- --00
---- --uu
TM2AL
0000 0000
0000 0000
0000 0000
uuuu uuuu
TM2AH
---- --00
---- --00
---- --00
---- --uu
Note: “u” stands for unchanged
“x” stands for “unknown”
“-“ stands for unimplemented
Rev. 1.30
63
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
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.
I/O Resistor Lists
HT66F24D
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
PAC
PAC7
PAC6
PAC5
PAC4
PAC3
PAC2
PAC1
PAC0
PA
PA7
PA6
PA5
PA4
PA3
PA2
PA1
PA0
PBPU
—
—
PBPU5
PBPU4
PBPU3
PBPU2
PBPU1
PBPU0
PBC0
PB
—
—
PBC5
PBC4
PBC3
PBC2
PBC1
PBC
—
—
PB5
PB4
PB3
PB2
PB1
PB0
PCPU
PCPU7
PCPU6
PCPU5
PCPU4
PCPU3
PCPU2
PCPU1
PCPU0
PC
PCC7
PCC6
PCC5
PCC4
PCC3
PCC2
PCC1
PCC0
PCC
PC7
PC4
PC5
PC4
PC3
PC2
PC1
PC0
HT66F25D/HT66F26D
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
PAC
PAC7
PAC6
PAC5
PAC4
PAC3
PAC2
PAC1
PAC0
PA
PA7
PA6
PA5
PA4
PA3
PA2
PA1
PA0
PBPU
PBPU7
PBPU6
PBPU5
PBPU4
PBPU3
PBPU2
PBPU1
PBPU0
PBC0
PB
PBC7
PBC6
PBC5
PBC4
PBC3
PBC2
PBC1
PBC
PB7
PB6
PB5
PB4
PB3
PB2
PB1
PB0
PCPU
PCPU7
PCPU6
PCPU5
PCPU4
PCPU3
PCPU2
PCPU1
PCPU0
PCC0
PC
PCC7
PCC6
PCC5
PCC4
PCC3
PCC2
PCC1
PCC
PC7
PC4
PC5
PC4
PC3
PC2
PC1
PC0
PDPU
—
—
—
—
—
—
PDPU1
PDPU0
PD
—
—
—
—
—
—
PDC1
PDC0
PDC
—
—
—
—
—
—
PD1
PD0
Rev. 1.30
64
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
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.
PAPU Register
Bit
7
6
5
4
3
2
1
0
Name
PAWU7
PAWU6
PAWU5
PAWU4
PAWU3
PAWU2
PAWU1
PAWU0
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 7~0
PAWU7~PAWU0: I/O Port A bit 7 ~ bit 0 Pull-high Control
0: Disable
1: Enable
PBPU Register
• HT66F24D
Bit
7
6
5
4
3
2
1
0
Name
—
—
PBPU5
PBPU4
PBPU3
PBPU2
PBPU1
PBPU0
R/W
—
—
R/W
R/W
R/W
R/W
R/W
R/W
POR
—
—
0
0
0
0
0
0
• HT66F25D/HT66F26D
Bit
7
6
5
4
3
2
1
0
Name
PBPU7
PBPU6
PBPU5
PBPU4
PBPU3
PBPU2
PBPU1
PBPU0
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
“—”: Unimplemented, read as 0
PBPUn:
I/O Port B bit n Pull-high Control
0: Disable
1: Enable
PCPU Register
• HT66F24D/HT66F25D/HT66F26D
Bit
7
6
5
4
3
2
1
0
Name
PCPU7
PCPU6
PCPU5
PCPU4
PCPU3
PCPU2
PCPU1
PCPU0
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
“—”: Unimplemented, read as 0
PCPUn:
I/O Port C bit n Pull-high Control
0: Disable
1: Enable
Rev. 1.30
65
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
PDPU Register
• HT66F25D/HT66F26D
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
—
—
PDPU1
PDPU0
R/W
—
—
—
—
—
—
R/W
R/W
POR
—
—
—
—
—
—
0
0
“—”: Unimplemented, read as 0
PDPUn:
I/O Port D bit n Pull-high Control
0: Disable
1: Enable
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.
PAWU Register
Bit
7
6
5
4
3
2
1
0
Name
PAWU7
PAWU6
PAWU5
PAWU4
PAWU3
PAWU2
PAWU1
PAWU0
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 7~0
PAWU: Port A bit 7 ~ bit 0 Wake-up Control
0: Disable
1: Enable
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 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 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.
PAC Register
Bit
7
6
5
4
3
2
1
0
Name
PAC7
PAC6
PAC5
PAC4
PAC3
PAC2
PAC1
PAC0
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 7~0
Rev. 1.30
PAC7~PAC0: I/O Port A bit 7 ~ bit 0 Input/Output Control
0: Output
1: Input
66
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
PBC Register
• HT66F24D
Bit
7
6
5
4
3
2
1
0
Name
—
—
PBC5
PBC4
PBC3
PBC2
PBC1
PBC0
R/W
—
—
R/W
R/W
R/W
R/W
R/W
R/W
POR
—
—
1
1
1
1
1
1
• HT66F25D/HT66F26D
Bit
7
6
5
4
3
2
1
0
Name
PBC7
PBC6
PBC5
PBC4
PBC3
PBC2
PBC1
PBC0
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
“—”: Unimplemented, read as 0
PBCn:
I/O Port B bit n Input/Output Control
0: Output
1: Input
PCC Register
• HT66F24D/HT66F25D/HT66F26D
Bit
7
6
5
4
3
2
1
0
Name
PCC7
PCC6
PCC5
PCC4
PCC3
PCC2
PCC1
PCC0
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
“—”: Unimplemented, read as 0
PCCn:
I/O Port C bit n Input/Output Control
0: Output
1: Input
PDC Register
• HT66F25D/HT66F26D
Rev. 1.30
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
—
—
PDC1
PDC0
R/W
—
—
—
—
—
—
R/W
R/W
POR
—
—
—
—
—
—
1
1
Bit 7~2
“—” Unimplemented, read as 0
Bit 1~0
PDC1~PDC0: I/O Port D bit 1 ~ bit 0 Input/Output Control
0: Output
1: Input
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Pin-remapping 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. The way in
which the pin function of each pin is selected is different for each function and a priority order is
established where more than one pin function is selected simultaneously. Additionally there is a
PRM0 register to establish certain pin functions.
Pin-remapping Registers
The limited number of supplied pins in a package can impose restrictions on the amount of functions
a certain device can contain. However by allowing the same pins to share several different functions
and providing a means of function selection, a wide range of different functions can be incorporated
into even relatively small package sizes. The devices include a PRM0 register which can select the
functions of certain pins.
PRM0 Register
Rev. 1.30
Bit
7
6
5
4
3
2
1
0
Name
INT1PS
INT0PS
TCK1PS
TCK0PS
—
—
—
—
R/W
R/W
R/W
R/W
R/W
—
—
—
—
POR
0
0
0
0
—
—
—
—
Bit 7
INT1PS: INT1 Pin Remapping Control
0: INT1 on PB0
1: INT1 on PC1
Bit 6
INT0PS: INT0 Pin Remapping Control
0: INT1 on PA2
1: INT1 on PC0
Bit 5
TCK1PS: TCK1 Pin Remapping Control
0: TCK1 on PB0
1: TCK1 on PC3
Bit 5
“—” Unimplemented, read as 0
Bit 4
TCK0PS: TCK0 Pin Remapping Control
0: TCK0 on PA6
1: TCK0 on PC2
Bit 3~0
“—” Unimplemented, read as 0
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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 pinshared structures does not permit all types to be shown. The diagrams illustrate the I/O pin internal
structures. As the exact logical construction of the I/O pin may differ from these drawings, they are
supplied as a guide only to assist with the functional understanding of the I/O pins.
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A/D Input/Output Structure
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
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 each 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 either
two or three 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 Enhanced TM sections.
Introduction
The devices contain up to three TMs with each TM having a reference name of TM0, TM1 and
TM2. Each individual TM can be categorised as a certain type, namely Compact Type TM (CTM),
Standard Type TM (STM) or Enhanced Type TM (ETM). Although similar in nature, the different
TM types vary in their feature complexity. The common features to all of the Compact, Standard
and Enhanced TMs will be described in this section and the detailed operation regarding each of the
TM types will be described in separate sections. The main features and differences between the three
types of TMs are summarised in the accompanying table.
CTM
STM
ETM
Timer/Counter
Function
√
√
√
I/P Capture
—
√
√
Compare Match Output
√
√
√
PWM Channels
1
1
2
Single Pulse Output
PWM Alignment
PWM Adjustment Period & Duty
—
1
2
Edge
Edge
Edge & Centre
Duty or Period
Duty or Period
Duty or Period
TM Function Summary
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Enhanced A/D Flash Type MCU with High Current LED Driver
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Each device in the series contains a specific number of either Compact Type, Standard Type and
Enhanced Type TM units which are shown in the table together with their individual reference name,
TM0~TM2.
Device
TM0
TM1
TM2
HT66F24D
10-bit CTM
10-bit STM
—
HT66F25D
10-bit CTM
10-bit ETM
—
HT66F26D
10-bit CTM
10-bit ETM
10-bit STM
TM Name/Type Reference
TM Operation
The three different types of TM 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 TnCK2~TnCK0 bits in the TM
control registers. The clock source can be a ratio of either the system clock fSYS or the high speed
clock fH, the fSUB clock source or the external TCKn pin. Note that setting these bits to the value 101
will select a reserved clock input, in effect disconnecting the TM clock source. The TCKn 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 and Standard type TMs each have two internal interrupts, one for each of the internal
comparator A or comparator P, which generate a TM interrupt when a compare match condition
occurs. As the Enhanced type TM has three internal comparators and comparator A or comparator
B or comparator P compare match functions, it consequently has three internal interrupts. 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.
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TM External Pins
Each of the TMs, irrespective of what type, has one TM input pin, with the label TCKn. The TM
input pin, is essentially a clock source for the TM and is selected using the TnCK2~TnCK0 bits in
the TMnC0 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 TnCK2~TnCK0 bits. The TM input pin can be chosen to have either a
rising or falling active edge.
The TMs each have one or more output pins with the label TPn. 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 TPn 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 and device is different, the details are
provided in the accompanying table. All TM output pin names have a “_n” suffix. Pin names that
include a “_1” or “_2” suffix indicate that they are from a TM with multiple output pins. This allows
the TM to generate a complimentary output pair, selected using the I/O register data bits.
Device
CTM
STM
ETM
Register
HT66F24D
TP0_0, TP0_1,
TP0_2
TP1_0, TP1_1,
TP1_2
—
TMPC0
HT66F25D
TP0_0, TP0_1,
TP0_2
—
TP1A_0, TP1A_1
TP1B_0, TP1B_1, TP1B_2
TMPC0
HT66F26D
TP0_0, TP0_1,
TP0_2
TP2_0, TP2_1,
TP2_2
TP1A_0, TP1A_1
TP1B_0, TP1B_1, TP1B_2
TMPC0
TMPC1
TM Output Pins
TM Input/Output Pin Control Registers
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 each 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.
Bit
Device
Register
HT66F24D
TMPC0
HT66F25D
TMPC0
T1ACP1 T1ACP0 T1BCP2 T1BCP1 T1BCP0 T0CP2 T0CP1 T0CP0
TMPC0
T1ACP1 T1ACP0 T1BCP2 T1BCP1 T1BCP0 T0CP2 T0CP1 T0CP0
HT66F26D
TMPC1
7
6
5
4
3
—
—
T1CP2
T1CP1
T1CP0
—
—
—
—
—
2
1
0
T0CP2 T0CP1 T0CP0
T2CP2 T2CP1 T2CP0
TM Input/Output Pin Control Register List
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HT66F24D/HT66F25D/HT66F26D
0
PA3 Output Function
1
0
1
PA3/TP0_0
T0CP0
PA3
PA0 Output Function
0
1
0
1
TM0
(CTM)
PA0/TP0_1
T0CP1
PA0
0
PA7 Output Function
Output
1
0
1
PA7/TP0_2
T0CP2
PA7
TCK Input
PA6/TCK1
0
PA4 Output Function
1
0
1
PA4/TP1_0
T1CP0
PA4
PA1 Output Function
0
1
0
1
TM1
(STM)
PA1/TP1_1
T1CP1
PA1
0
PB1 Output Function
Output
1
0
1
PB1
Capture Input
PB1/TP1_2
T1CP2
1
0
T1CP2
1
0
T1CP1
1
0
T1CP0
TCK Input
PB0/TCK1
Note: (1) The I/O register data bits shown are used for TM output inversion control.
(2) In the Capture Input Mode, the TM pin control register must never enable more than
one TM input.
HT66F24D TM0 & TM1 Function Pin Control Block Diagram
Rev. 1.30
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HT66F24D/HT66F25D/HT66F26D
0
PA3 Output Function
1
0
1
PA3/TP0_0
T0CP0
PA3
PA0 Output Function
0
1
0
1
TM0
(CTM)
PA0/TP0_1
T0CP1
PA0
0
PA7 Output Function
Output
1
0
1
PA7/TP0_2
T0CP2
PA7
TCK Input
PA6/TCK1
PA5 Output Function
0
1
0
1
PA5/TP1A_0
T1ACP0
PA5
PB2 Output Function
Output
0
1
0
1
PB2/TP1A_1
T1ACP1
PB2
Capture Input
1
0
T1ACP1
1
0
T1ACP0
0
PA4 Output Function
1
0
1
PA4/TP1B_0
T1BCP0
PA4
PA1 Output Function
0
1
0
1
TM1
(ETM)
PA1/TP1_1
T1BCP1
PA1
0
PB1 Output Function
CCRB Output
1
0
1
PB1/TP1B_2
T1BCP2
PB1
CCRB Capture Input
1
0
T1BCP2
1
0
T1BCP1
1
0
T1BCP0
TCK Input
PB0/TCK1
Note: (1) The I/O register data bits shown are used for TM output inversion control.
(2) In the Capture Input Mode, the TM pin control register must never enable more than
one TM input.
HT66F25D TM0 & TM1 Function Pin Control Block Diagram
Rev. 1.30
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HT66F24D/HT66F25D/HT66F26D
P A 3 O u tp u t F u n c tio n
0
P A 3 /T P 0 _ 0
1
0
1
T 0 C P 0
P A 3
P A 0 O u tp u t F u n c tio n
0
P A 0 /T P 0 _ 1
1
0
1
T 0 C P 1
P A 0
P A 7 O u tp u t F u n c tio n
0
P A 7 /T P 0 _ 2
1
O u tp u t
0
1
T 0 C P 2
P A 7
T C K In p u t
P A 6 /T C K 1
P C 4 O u tp u t F u n c tio n
0
P C 4 /T P 2 _ 0
1
0
1
T 2 C P 0
P C 4
P C 5 O u tp u t F u n c tio n
0
P C 5 /T P 2 _ 1
1
0
1
T 2 C P 1
P C 5
P C 6 O u tp u t F u n c tio n
O u tp u t
0
1
0
1
P C 6 /T P 2 _ 2
T 2 C P 2
P C 6
1
C a p tu re In p u t
0
T 2 C P 2
1
0
T 2 C P 1
1
0
T 2 C P 0
T C K In p u t
Rev. 1.30
P C 7 /T C K 2
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P A 5 O u tp u t F u n c tio n
0
P A 5 /T P 1 A _ 0
1
0
1
T 1 A C P 0
P A 5
P B 2 O u tp u t F u n c tio n
0
P B 2 /T P 1 A _ 1
1
O u tp u t
0
1
T 1 A C P 1
P B 2
1
C a p tu re In p u t
0
T 1 A C P 1
1
0
T 1 A C P 0
P A 4 O u tp u t F u n c tio n
0
P A 4 /T P 1 B _ 0
1
0
1
T 1 B C P 0
P A 4
P A 1 O u tp u t F u n c tio n
0
P A 1 /T P 1 B _ 1
1
0
1
T 1 B C P 1
P A 1
P B 1 O u tp u t F u n c tio n
C C R B O u tp u t
0
1
0
1
P B 1 /T P 1 B _ 2
T 1 B C P 2
P B 1
1
C C R B C a p tu re In p u t
0
T 1 B C P 2
1
0
T 1 B C P 1
1
0
T 1 B C P 0
T C K In p u t
P B 0 /T C K 1
Note: (1) The I/O register data bits shown are used for TM output inversion control.
(2) In the Capture Input Mode, the TM pin control register must never enable more than
one TM input.
HT66F26D TM Function Pin Control Block Diagram
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
TMPC0 Register
• HT66F24D
Rev. 1.30
Bit
Register
Name
7
6
5
4
3
2
1
0
Name
—
—
T1CP2
T1CP1
T1CP0
T0CP2
T0CP1
T0CP0
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
T1CP2: TP1_2 pin enable Control
0: Disable
1: Enable
Bit 4
T1CP1: TP1_1 pin enable Control
0: Disable
1: Enable
Bit 3
T1CP0: TP1_0 pin enable Control
0: Disable
1: Enable
Bit 2
T0CP2: TP0_2 pin enable Control
0: Disable
1: Enable
Bit 1
T0CP1: TP0_1 pin enable Control
0: Disable
1: Enable
Bit 0
T0CP0: TP0_0 pin enable Control
0: Disable
1: Enable
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
• HT66F25D/HT66F26D
Bit
Register
Name
7
6
5
4
3
2
1
0
Name
T1ACP1
T1ACP0
T1BCP2
T1BCP1
T1BCP0
T0CP2
T0CP1
T0CP0
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
3
2
1
0
Bit 7
T1ACP1: TP1A_1 pin enable Control
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0: Disable
1: Enable
T1ACP0: TP1A_0 pin enable Control
0: Disable
1: Enable
T1BCP2: TP1B_2 pin enable Control
0: Disable
1: Enable
T1BCP1: TP1B_1 pin enable Control
0: Disable
1: Enable
T1BCP0: TP1B_0 pin enable Control
0: Disable
1: Enable
T0CP2: TP0_2 pin enable Control
0: Disable
1: Enable
T0CP1: TP0_1 pin enable Control
0: Disable
1: Enable
T0CP0: TP0_0 pin enable Control
0: Disable
1: Enable
TMPC1 Register
• HT66F26D
Register
Name
Rev. 1.30
Bit
7
6
5
4
Name
—
—
—
—
—
T2CP2
T2CP1
T2CP0
R/W
—
—
—
—
—
R/W
R/W
R/W
POR
—
—
—
—
—
0
0
0
Bit 7~3
“—” Unimplemented, read as 0
Bit 2
Bit 1
Bit 0
T2CP2: TP2_2 pin enable Control
0: Disable
1: Enable
T2CP1: TP2_1 pin enable Control
0: Disable
1: Enable
T2CP0: TP2_0 pin enable Control
0: Disable
1: Enable
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Enhanced A/D Flash Type MCU with High Current LED Driver
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Programming Considerations
The TM Counter Registers and the Capture/Compare CCRA and CCRB registers, being 10-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 CCRB registers are implemented in the way shown in the
following diagram and accessing these register pairs is carried out in a specific way described above,
it is recommended to use the “MOV” instruction to access the CCRA and CCRB low byte registers,
named TMxAL and TMxBL, using the following access procedures. Accessing the CCRA or CCRB
low byte registers without following these access procedures will result in unpredictable values.
T� Counte� Registe� (Read only)
T�xDL
TMxDH
8-bit
Buffe�
T�xAL
TMxAH
T� CCRA Registe� (Read/W�ite)
T�xBL
TMxBH
T� CCRB Registe� (Read/W�ite)
Data
Bus
The following steps show the read and write procedures:
Writing Data to CCRB or CCRA
• Step 1. Write data to Low Byte TMxAL or TMxBL - note that here data is only written to the 8-bit
buffer.
• Step 2. Write data to High Byte TMxAH or TMxBH - 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 CCRB or CCRA
• Step 1. Read data from the High Byte TMxDH, TMxAH or TMxBH - 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 TMxDL, TMxAL or TMxBL - 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 or more
external output pins. These external output pins can be the same signal or the inverse signal.
CTM
HT66F24D
HT66F25D
HT66F26D
Name
TM No.
TM Input Pin
TM Output Pin
10-bit CTM
0
TCK0
TP0_0, TP0_1, TP0_2
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 TnON 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 an output pin. All operating setup conditions are
selected using relevant internal registers.
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  ­ ­ ­     Compact Type TM Block Diagram
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
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Compact Type TM Register Description
Overall operation of the Compact TM is controlled using six 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.
CTM Register List
Bit
Register
Name
7
6
5
4
3
2
1
0
TM0C0
T0PAU
T0CK2
T0CK1
T0CK0
T0ON
T0RP2
T0RP1
T0RP0
TM0C1
T0M1
T0M0
T0IO1
T0IO0
T0OC
T0POL
T0DPX
T0CCLR
TM0DL
D7
D6
D5
D4
D3
D2
D1
D0
TM0DH
—
—
—
—
—
—
D9
D8
TM0AL
D7
D6
D5
D4
D3
D2
D1
D0
TM0AH
—
—
—
—
—
—
D9
D8
10-bit Compact TM Register List
TM0DL Register
Bit
Register
Name
7
6
5
4
3
2
1
0
TM0C0
D7
D6
D5
D4
D3
D2
D1
D0
TM0C1
R
R
R
R
R
R
R
R
TM0DL
0
0
0
0
0
0
0
0
Bit 7~0
TM0DL: TM0 Counter Low Byte Register bit 7 ~ bit 0
TM0 10-bit Counter bit 7 ~ bit 0
TM0DH Register
Bit
Register
Name
7
6
5
4
3
2
1
0
TM0C0
—
—
—
—
—
—
D9
D8
TM0C1
—
—
—
—
—
—
R
R
TM0DL
—
—
—
—
—
—
0
0
Bit 7~2
“—” Unimplemented, read as 0
Bit 1~0
TM0DH: TM0 Counter High Byte Register bit 1 ~ bit 0
TM0 10-bit Counter bit 9 ~ bit 8
TM0AL Register
7
6
5
4
3
2
1
0
TM0C0
D7
D6
D5
D4
D3
D2
D1
D0
TM0C1
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
TM0DL
0
0
0
0
0
0
0
0
Bit 7~0
Rev. 1.30
Bit
Register
Name
TM0AL: TM0 CCRA Low Byte Register bit 7 ~ bit 0
TM0 10-bit CCRA bit 7 ~ bit 0
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TM0AH Register
Bit
Register
Name
7
6
5
4
3
2
1
0
TM0C0
—
—
—
—
—
—
D9
D8
TM0C1
—
—
—
—
—
—
R/W
R/W
TM0DL
—
—
—
—
—
—
0
0
Bit 7~2
“—” Unimplemented, read as 0
Bit 1~0
TM0AH: TM0 CCRA High Byte Register bit 1 ~ bit 0
TM0 10-bit CCRA bit 9 ~ bit 8
TM0C0 Register
Rev. 1.30
Bit
Register
Name
7
6
5
4
3
2
1
0
TM0C0
T0PAU
T0CK2
T0CK1
T0CK0
T0ON
T0RP2
T0RP1
T0RP0
TM0C1
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
TM0DL
0
0
0
0
0
0
0
0
Bit 7
T0PAU: TM0 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
T0CK2~T0CK0: Select TM0 Counter clock
000: fSYS/4
001: fSYS
010: fH/16
011: fH/64
100: fSUB
101: undefined, can not be selected.
110: TCK0 rising edge clock
111: TCK0 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 fSUB are other internal clocks, the details of which can
be found in the oscillator section.
Bit 3
T0ON: TM0 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 and 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.
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 T0OC bit, when the T0ON bit changes from
low to high.
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Bit 2~0
T0RP2~T0RP0: TM0 CCRP 3-bit register, compare with the TM0 counter bit 9~bit 7
Comparator P Match Period
000: 1024 TM0 clocks
001: 128 TM0 clocks
010: 256 TM0 clocks
011: 384 TM0 clocks
100: 512 TM0 clocks
101: 640 TM0 clocks
110: 768 TM0 clocks
111: 896 TM0 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 T0CCLR bit is set to
zero. Setting the T0CCLR 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.
TM0C1 Register
Rev. 1.30
Bit
Register
Name
7
6
5
4
3
2
1
0
TM0C0
T0M1
T0M0
T0IO1
T0IO0
T0OC
T0POL
T0DPX
T0CCLR
TM0C1
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
TM0DL
0
0
0
0
0
0
0
0
Bit 7~6
T0M1~T0M0: Select TM0 Operation Mode
00: Compare Match Output Mode
01: Undefined
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 T0M1 and T0M0
bits. In the Timer/Counter Mode, the TM output pin control must be disabled.
Bit 5~4
T0IO1~T0IO0: Select TP0_0, TP0_1, TP0_2 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 T0IO1 and T0IO0 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 T0OC bit in the TM0C1 register. Note that the output
level requested by the T0IO1 and T0IO0 bits must be different from the initial value
setup using the T0OC 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 T0ON bit from low to high.
In the PWM Mode, the TnIO1 and TnIO0 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 TnIO1 and TnIO0 bits only after the TMn has been switched off. Unpredictable
PWM outputs will occur if the TnIO1 and TnIO0 bits are changed when the TM is
running
Rev. 1.30
Bit 3
T0OC: TP0_0, TP0_1, TP0_2 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 2
T0POL: TP0_0, TP0_1, TP0_2 output Polarity control
0: Non-invert
1: Invert
This bit controls the polarity of the TP0_0, TP0_1 or TP0_2 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 1
T0DPX: TM0 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 0
T0CCLR: Select TM0 Counter clear condition
0: TM0 Comparator P match
1: TM0 Comparator 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 T0CCLR 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 T0CCLR bit is not
used in the PWM Mode.
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Enhanced A/D Flash Type MCU with High Current LED Driver
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Compact Type TM Operation Modes
The Compact Type TM can operate in one of three operating modes, Compare Match Output Mode,
PWM Mode or Timer/Counter Mode. The operating mode is selected using the TnM1 and TnM0
bits in the TMnC1 register.
Compare Match Output Mode
To select this mode, bits TnM1 and TnM0 in the TMnC1 register, should be set to 00B 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 TnCCLR bit is low, there are two ways in which the counter can be cleared. One is when
a compare match occurs from Comparator P, the other is when the CCRP bits are all zero which
allows the counter to overflow. Here both TnAF and TnPF interrupt request flags for the Comparator
A and Comparator P respectively, will both be generated.
If the TnCCLR bit in the TMnC1 register is high then the counter will be cleared when a compare
match occurs from Comparator A. However, here only the TnAF interrupt request flag will be
generated even if the value of the CCRP bits is less than that of the CCRA registers. Therefore when
TnCCLR is high no TnPF 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 TnAF
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 TnAF interrupt request flag
is generated after a compare match occurs from Comparator A. The TnPF 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
TnIO1 and TnIO0 bits in the TMnC1 register. The TM output pin can be selected using the TnIO1
and TnIO0 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
TnON bit changes from low to high, is setup using the TnOC bit. Note that if the TnIO1 and TnIO0
bits are zero then no pin change will take place.
Rev. 1.30
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Counter overflow
Counter Value
CCRP=0
0x3FF
TnCCLR = 0; TnM [1:0] = 00
CCRP > 0
Counter cleared by CCRP value
CCRP > 0
Counter
Restart
Resume
CCRP
Pause
CCRA
Stop
Time
TnON
TnPAU
TnPOL
CCRP Int.
Flag TnPF
CCRA Int.
Flag TnAF
TM O/P Pin
Output pin set to
initial Level Low
if TnOC=0
Output not affected by TnAF
flag. Remains High until reset
by TnON bit
Output Toggle with
TnAF flag
Here TnIO [1:0] = 11
Toggle Output select
Note TnIO [1:0] = 10
Active High Output select
Output Inverts
when TnPOL is high
Output Pin
Reset to Initial value
Output controlled by
other pin-shared function
Compare Match Output Mode – TnCCLR=0
Note: 1. With TnCCLR=0, a Comparator P match will clear the counter
2. The TM output pin is controlled only by the TnAF flag
3. The output pin is reset to its initial state by a TnON bit rising edge
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
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Counter Value
TnCCLR = 1; TnM [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
TnON
TnPAU
TnPOL
No TnAF flag
generated on
CCRA overflow
CCRA Int.
Flag TnAF
CCRP Int.
Flag TnPF
TnPF not
generated
Output does
not change
TM O/P Pin
Output pin set to
initial Level Low
if TnOC=0
Output not affected by
TnAF flag. Remains High
until reset by TnON bit
Output Toggle with
TnAF flag
Here TnIO [1:0] = 11
Toggle Output select
Note TnIO [1:0] = 10
Active High Output select
Output Inverts
when TnPOL is high
Output Pin
Reset to Initial value
Output controlled by
other pin-shared function
Compare Match Output Mode – TnCCLR=1
Note: 1. With TnCCLR=1, a Comparator A match will clear the counter
2. The TM output pin is controlled only by the TnAF flag
3. The output pin is reset to its initial state by a TnON bit rising edge
4. The TnPF flag is not generated when TnCCLR=1
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
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Timer/Counter Mode
To select this mode, bits TnM1 and TnM0 in the TMnC1 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 TnM1 and TnM0 in the TMnC1 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 TnCCLR bit has no effect on the PWM
operation. 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 TnDPX bit in the TMnC1 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 TnOC bit in the TMnC1 register is used to
select the required polarity of the PWM waveform while the two TnIO1 and TnIO0 bits are used to
enable the PWM output or to force the TM output pin to a fixed high or low level. The TnPOL bit is
used to reverse the polarity of the PWM output waveform.
CTM, PWM Mode, Edge-aligned Mode, T0DPX=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 and 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, T0DPX=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 cycle is determined by the CCRA register value together with the TM clock
while the PWM duty cycle is defined by the CCRP register value.
Rev. 1.30
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Counter Value
TnDPX = 0; TnM [1:0] = 10
Counter cleared
by CCRP
Counter Reset when
TnON returns high
CCRP
Pause Resume
CCRA
Counter Stop if
TnON bit low
Time
TnON
TnPAU
TnPOL
CCRA Int.
Flag TnAF
CCRP Int.
Flag TnPF
TM O/P Pin
(TnOC=1)
TM O/P Pin
(TnOC=0)
PWM resumes
operation
PWM Duty Cycle
set by CCRA
PWM Period
set by CCRP
Output controlled by
other pin-shared function
Output Inverts
when TnPOL = 1
PWM Mode – TnDPX=0
Note: 1. Here TnDPX=0 – Counter cleared by CCRP
2. A counter clear sets the PWM Period
3. The internal PWM function continues running even when TnIO [1:0] = 00 or 01
4. The TnCCLR bit has no influence on PWM operation
Rev. 1.30
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Counter Value
TnDPX = 1; TnM [1:0] = 10
Counter cleared
by CCRA
Counter Reset when
TnON returns high
CCRA
Pause Resume
CCRP
Counter Stop if
TnON bit low
Time
TnON
TnPAU
TnPOL
CCRP Int.
Flag TnPF
CCRA Int.
Flag TnAF
TM O/P Pin
(TnOC=1)
TM O/P Pin
(TnOC=0)
PWM Duty Cycle
set by CCRP
PWM Period
set by CCRA
PWM resumes
operation
Output controlled by
Output Inverts
other pin-shared function
when TnPOL = 1
PWM Mode – TnDPX=1
Note: 1. Here TnDPX = 1 – Counter cleared by CCRA
2. A counter clear sets the PWM Period
3. The internal PWM function continues running even when TnIO [1:0] = 00 or 01
4. The TnCCLR bit has no influence on PWM operation
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
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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
also be controlled with an external input pin and can drive one or more external output pins.
STM
Name
TM No.
TM Input Pin
TM Output Pin
HT66F24D
HT66F25D
10-bit STM
1
TCK1
TP1_0, TP1_1, TP1_2
—
—
—
—
HT66F26D
10-bit STM
2
TCK2
TP2_0, TP2_1, TP2_2
Standard 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 TnON 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 Block Diagram
Rev. 1.30
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Standard Type TM Register Description
Overall operation of the Standard TM is controlled using a series of 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.
STM Register List – HT66F24D/HT66F26D
Bit
Register
Name
7
6
5
4
3
2
1
0
TM1C0
T1PAU
T1CK2
T1CK1
T1CK0
T1ON
T1RP2
T1RP1
T1RP0
TM1C1
T1M1
T1M0
T1IO1
T1IO0
T1OC
T1POL
T1DPX
T1CCLR
TM1DL
D7
D6
D5
D4
D3
D2
D1
D0
TM1DH
—
—
—
—
—
—
D9
D8
TM1AL
D7
D6
D5
D4
D3
D2
D1
D0
TM1AH
—
—
—
—
—
—
D9
D8
10-bit Standard TM Register List (n=1 for HT66F24D; n=2 for HT66F26D)
TMnDL Register
Bit
Register
Name
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 7~0
TMnDL: TMn Counter Low Byte Register bit 7 ~ bit 0
TMn 10-bit Counter bit 7 ~ bit 0
TMnDH Register
Bit
Register
Name
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 1~0
TMnDH: TMn Counter High Byte Register bit 1 ~ bit 0
TMn 10-bit Counter bit 9 ~ bit 8
TMnAL Register
Rev. 1.30
Bit
Register
Name
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 7~0
TMnAL: TMn CCRA Low Byte Register bit 7 ~ bit 0
TMn 10-bit CCRA bit 7 ~ bit 0
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Enhanced A/D Flash Type MCU with High Current LED Driver
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TMnAH Register
Bit
Register
Name
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 1~0
TMnAH: TMn CCRA High Byte Register bit 1 ~ bit 0
TMn 10-bit CCRA bit 9 ~ bit 8
TMnC0 Register
Rev. 1.30
Bit
Register
Name
7
6
5
4
3
2
1
0
Name
T1PAU
T1CK2
T1CK1
T1CK0
T1ON
T1RP2
T1RP1
T1RP0
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
TnPAU: TMn 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
TnCK2~TnCK0: Select TMn Counter clock
000: fSYS/4
001: fSYS
010: fH/16
011: fH/64
100: fSUB
101: Undefined, can not be selected.
110: TCKn rising edge clock
111: TCKn 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 fSUB are other internal clocks, the details of which can
be found in the oscillator section.
Bit 3
TnON: TMn 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 and 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.
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 TnOC bit, when the TnON bit changes from
low to high.
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Bit 2~0
TnRP2~TnRP0: TMn CCRP 3-bit register, compare with the TMn counter bit 9~bit 7
Comparator P Match Period
000: 1024 TMn clocks
001: 128 TMn clocks
010: 256 TMn clocks
011: 384 TMn clocks
100: 512 TMn clocks
101: 640 TMn clocks
110: 768 TMn clocks
111: 896 TMn 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 TnCCLR bit is set to
zero. Setting the TnCCLR 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.
TMnC1 Register
Rev. 1.30
Bit
Register
Name
7
6
5
4
3
2
1
0
Name
TnM1
TnM0
TnIO1
TnIO0
TnOC
TnPOL
TnDPX
TnCCLR
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
TnM1~TnM0: Select TMn Operation 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 TnM1 and TnM0
bits. In the Timer/Counter Mode, the TM output pin control must be disabled.
Bit 5~4
TnIO1~TnIO0: Select TPn_0, TPn_1, TPn_2 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 TPn_0, TPn_1, TPn_2
01: Input capture at falling edge of TPn_0, TPn_1, TPn_2
01: Input capture at falling/rising edge of TPn_0, TPn_1, TPn_2
11: Input capture disabled
Timer/Counter Mode
Unused.
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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 TnIO1 and TnIO0 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 TnOC bit in the TMnC1 register. Note that the output
level requested by the TnIO1 and TnIO0 bits must be different from the initial value
setup using the TnOC 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 T1ON bit from low to high.
In the PWM Mode, the TnIO1 and TnIO0 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 TnIO1 and TnIO0 bits only after the TM has been switched off. Unpredictable
PWM outputs will occur if the TnIO1 and TnIO0 bits are changed when the TM is
running
Rev. 1.30
Bit 3
TnOC: TPn_0, TPn_1, TPn_2 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 2
TnPOL: TPn_0, TPn_1, TPn_2 output Polarity control
0: Non-invert
1: Invert
This bit controls the polarity of the TPn_0, TPn_1 or TPn_2 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 1
TnDPX: TMn 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 0
TnCCLR: Select TMn Counter clear condition
0: TMn Comparator P match
1: TMn 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 TnCCLR 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 TnCCLR bit is not
used in the PWM Mode, Single Pulse or Input Capture Mode.
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Standard Type TM Operation Modes
The Standard Type TM can operate in one of five operating modes, Compare Match Output
Mode, PWM Mode, Single Pulse Output Mode, Capture Input Mode or Timer/Counter Mode. The
operating mode is selected using the TnM1 and TnM0 bits in the TMnC1 register.
Compare Match Output Mode
To select this mode, bits TnM1 and TnM0 in the TMnC1 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 TnCCLR 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 TnAF and TnPF interrupt request flags for Comparator A and
Comparator P respectively, will both be generated.
If the TnCCLR bit in the TMnC1 register is high then the counter will be cleared when a compare
match occurs from Comparator A. However, here only the TnAF interrupt request flag will be
generated even if the value of the CCRP bits is less than that of the CCRA registers. Therefore when
TnCCLR is high no TnPF 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 TnAF interrupt request flag
is generated after a compare match occurs from Comparator A. The TnPF 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
TnIO1 and TnIO0 bits in the TMnC1 register. The TM output pin can be selected using the TnIO1
and TnIO0 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
TnON bit changes from low to high, is setup using the TnOC bit. Note that if the TnIO1 and TnIO0
bits are zero then no pin change will take place.
Rev. 1.30
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Counter overflow
Counter Value
CCRP=0
0x3FF
TnCCLR = 0; TnM [1:0] = 00
CCRP > 0
Counter cleared by CCRP value
CCRP > 0
Counter
Restart
Resume
CCRP
Pause
CCRA
Stop
Time
TnON
TnPAU
TnPOL
CCRP Int.
Flag TnPF
CCRA Int.
Flag TnAF
TM O/P Pin
Output pin set to
initial Level Low
if TnOC=0
Output not affected by TnAF
flag. Remains High until reset
by TnON bit
Output Toggle with
TnAF flag
Here TnIO [1:0] = 11
Toggle Output select
Note TnIO [1:0] = 10
Active High Output select
Output Inverts
when TnPOL is high
Output Pin
Reset to Initial value
Output controlled by
other pin-shared function
Compare Match Output Mode – TnCCLR=0
Note: 1. With TnCCLR=0, a Comparator P match will clear the counter
2. The TM output pin is controlled only by the TnAF flag
3. The output pin is reset to its initial state by a TnON bit rising edge
Rev. 1.30
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Counter Value
TnCCLR = 1; TnM [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
TnON
TnPAU
TnPOL
No TnAF flag
generated on
CCRA overflow
CCRA Int.
Flag TnAF
CCRP Int.
Flag TnPF
TnPF not
generated
Output does
not change
TM O/P Pin
Output pin set to
initial Level Low
if TnOC=0
Output not affected by
TnAF flag. Remains High
until reset by TnON bit
Output Toggle with
TnAF flag
Here TnIO [1:0] = 11
Toggle Output select
Note TnIO [1:0] = 10
Active High Output select
Output Inverts
when TnPOL is high
Output Pin
Reset to Initial value
Output controlled by
other pin-shared function
Compare Match Output Mode – TnCCLR=1
Note: 1. With TnCCLR=1, a Comparator A match will clear the counter
2. The TM output pin is controlled only by the TnAF flag
3. The output pin is reset to its initial state by a TnON bit rising edge
4. A TnPF flag is not generated when TnCCLR=1
Rev. 1.30
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Timer/Counter Mode
To select this mode, bits TnM1 and TnM0 in the TMnC1 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 TnM1 and TnM0 in the TMnC1 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 TnCCLR bit has no effect on the PWM
operation. 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 TnDPX bit in the TMnC1 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 TnOC bit in the TMnC1 register is used to
select the required polarity of the PWM waveform while the two TnIO1 and TnIO0 bits are used to
enable the PWM output or to force the TM output pin to a fixed high or low level. The TnPOL bit is
used to reverse the polarity of the PWM output waveform.
STM, PWM Mode, Edge-aligned Mode, T0DPX=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 select fSYS/4, CCRP = 100b and CCRA = 128,
The STM 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%.
STM, PWM Mode, Edge-aligned Mode, T0DPX=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 cycle is determined by the CCRA register value together with the TM clock
while the PWM duty cycle is defined by the CCRP register value.
Rev. 1.30
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Counter Value
TnDPX = 0; TnM [1:0] = 10
Counter cleared
by CCRP
Counter Reset when
TnON returns high
CCRP
Pause Resume
CCRA
Counter Stop if
TnON bit low
Time
TnON
TnPAU
TnPOL
CCRA Int.
Flag TnAF
CCRP Int.
Flag TnPF
TM O/P Pin
(TnOC=1)
TM O/P Pin
(TnOC=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 TnPOL = 1
PWM Mode – TnDPX=0
Note: 1. Here TnDPX=0 – Counter cleared by CCRP
2. A counter clear sets the PWM Period
3. The internal PWM function continues running even when TnIO [1:0] = 00 or 01
4. The TnCCLR bit has no influence on PWM operation
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Counter Value
TnDPX = 1; TnM [1:0] = 10
Counter cleared
by CCRA
Counter Reset when
TnON returns high
CCRA
Pause Resume
CCRP
Counter Stop if
TnON bit low
Time
TnON
TnPAU
TnPOL
CCRP Int.
Flag TnPF
CCRA Int.
Flag TnAF
TM O/P Pin
(TnOC=1)
TM O/P Pin
(TnOC=0)
PWM Duty Cycle
set by CCRP
PWM Period
set by CCRA
PWM resumes
operation
Output controlled by
Output Inverts
other pin-shared function
when TnPOL = 1
PWM Mode – TnDPX=1
Note: 1. Here TnDPX=1 – Counter cleared by CCRA
2. A counter clear sets the PWM Period
3. The internal PWM function continues running even when TnIO [1:0] = 00 or 01
4. The TnCCLR bit has no influence on PWM operation
Rev. 1.30
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Single Pulse Mode
To select this mode, bits TnM1 and TnM0 in the TMnC1 register should be set to 10 respectively
and also the TnIO1 and TnIO0 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 TnON bit, which can
be implemented using the application program. However in the Single Pulse Mode, the TnON bit
can also be made to automatically change from low to high using the external TCKn pin, which will
in turn initiate the Single Pulse output. When the TnON bit transitions to a high level, the counter
will start running and the pulse leading edge will be generated. The TnON bit should remain high
when the pulse is in its active state. The generated pulse trailing edge will be generated when the
TnON 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
TnM [1:0] = 10 ; TnIO [1:0] = 11
Counter stopped
by CCRA
Counter Reset when
TnON returns high
CCRA
Pause
Counter Stops
by software
Resume
CCRP
Time
TnON
Software
Trigger
Auto. set by
TCKn pin
Cleared by
CCRA match
TCKn pin
Software
Trigger
Software
Trigger
Software
Software Trigger
Clear
TCKn pin
Trigger
TnPAU
TnPOL
CCRP Int.
Flag TnPF
No CCRP Interrupts
generated
CCRA Int.
Flag TnAF
TM O/P Pin
(TnOC=1)
TM O/P Pin
(TnOC=0)
Output Inverts
when TnPOL = 1
Pulse Width
set by CCRA
Single Pulse Mode
Note: 1. Counter stopped by CCRA
2. CCRP is not used
3. The pulse is triggered by the TCKn pin or by setting the TnON bit high
4. A TCKn pin active edge will automatically set the TnON bit high.
5. In the Single Pulse Mode, TnIO [1:0] must be set to “11” and can not be changed.
However a compare match from Comparator A will also automatically clear the TnON 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 TnON bit changes from low to high when the counter
restarts. In the Single Pulse Mode CCRP is not used. The TnCCLR and TnDPX bits are not used in
this Mode.
Rev. 1.30
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Capture Input Mode
To select this mode bits TnM1 and TnM0 in the TMnC1 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 TPn_0, TPn_1 or TPn_2 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 TnIO1 and
TnIO0 bits in the TMnC1 register. The counter is started when the TnON bit changes from low to
high which is initiated using the application program.
When the required edge transition appears on the TPn_0, TPn_1 or TPn_2 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 TPn_0, TPn_1 or TPn_2 pin the counter will continue to free run until the
TnON 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 TnIO1 and TnIO0 bits can select the active trigger edge on the TPn_0, TPn_1
or TPn_2 pin to be a rising edge, falling edge or both edge types. If the TnIO1 and TnIO0 bits are
both set high, then no capture operation will take place irrespective of what happens on the TPn_0,
TPn_1 or TPn_2 pin, however it must be noted that the counter will continue to run.
As the TPn_0, TPn_1 or TPn_2 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 TnCCLR and TnDPX bits are not
used in this Mode.
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Counter Value
TnM [1:0] = 01
Counter cleared
by CCRP
Counter Counter
Stop
Reset
CCRP
YY
Pause
Resume
XX
Time
TnON
TnPAU
TM capture
pin TPn_x
Active
edge
Active
edge
Active edge
CCRA Int.
Flag TnAF
CCRP Int.
Flag TnPF
CCRA
Value
TnIO [1:0]
Value
XX
00 – Rising edge
YY
01 – Falling edge
XX
10 – Both edges
YY
11 – Disable Capture
Capture Input Mode
Note: 1. TnM [1:0] = 01 and active edge set by the TnIO [1:0] bits
2. A TM Capture input pin active edge transfers the counter value to CCRA
3. TnCCLR bit not used
4. No output function – TnOC and TnPOL bits are not used
5. CCRP determines the counter value and the counter has a maximum
count value when CCRP is equal to zero.
Rev. 1.30
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Enhanced Type TM – ETM
The Enhanced Type TM contains five operating modes, which are Compare Match Output, Timer/
Event Counter, Capture Input, Single Pulse Output and PWM Output modes. The Enhanced TM can
also be controlled with an external input pin and can drive two or more external output pins.
ETM
Name
TM No.
TM Input Pin
HT66F24D
—
—
—
—
TCK1
TP1A_0, TP1A_1
TP1B_0, TP1B_1, TP1B_2
HT66F25D/HT66F26D
10-bit ETM
1
TM Output Pin
Enhanced TM Operation
At its core is a 10-bit count-up/count-down counter which is driven by a user selectable internal
or external clock source. There are three internal comparators with the names, Comparator A,
Comparator B and Comparator P. These comparators will compare the value in the counter with the
CCRA, CCRB and CCRP registers. The CCRP comparator is 3 bits wide whose value is compared
with the highest 3 bits in the counter while CCRA and CCRB are 10 bits wide and therefore
compared 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 TnON 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 Enhanced
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 output pins. All operating setup conditions are
selected using relevant internal registers.
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Enhanced Type TM Block Diagram
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Enhanced Type TM Register Description
Overall operation of the Enhanced 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 and CCRB value. The remaining three registers are control registers which
setup the different operating and control modes as well as the three CCRP bits.
ETM Register List – HT66F25D/HT66F26D
Bit
Register
Name
7
6
5
4
3
2
1
0
TM1C0
T1PAU
T1CK2
T1CK1
T1CK0
T1ON
T1RP2
T1RP1
T1RP0
TM1C1
T1AM1
T1AM0
T1AIO1
T1AIO0
T1AOC
T1APOL
T1CDN
T1CCLR
TM1C2
T1BM1
T1BM0
T1BIO1
T1BIO0
T1BOC
T1BPOL
T1PWM1
T1PWM0
TM1DL
D7
D6
D5
D4
D3
D2
D1
D0
D8
TM1DH
—
—
—
—
—
—
D9
TM1AL
D7
D6
D5
D4
D3
D2
D1
D0
TM1AH
—
—
—
—
—
—
D9
D8
TM1BL
D7
D6
D5
D4
D3
D2
D1
D0
TM1BH
—
—
—
—
—
—
D9
D8
10-bit Enhanced TM Register List
TM1DL Register
Bit
Register
Name
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 7~0
TM1DL: TM1 Counter Low Byte Register bit 7 ~ bit 0
TM1 10-bit Counter bit 7 ~ bit 0
TM1DH Register
Bit
Register
Name
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 1~0
TM1DH: TM1 Counter High Byte Register bit 1 ~ bit 0
TM1 10-bit Counter bit 9 ~ bit 8
TM1AL Register
Rev. 1.30
Bit
Register
Name
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 7~0
TM1AL: TM1 CCRA Low Byte Register bit 7 ~ bit 0
TM1 10-bit CCRA bit 7 ~ bit 0
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HT66F24D/HT66F25D/HT66F26D
TM1AH Register
Bit
Register
Name
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 1~0
TM1AH: TM1 CCRA High Byte Register bit 1 ~ bit 0
TM1 10-bit CCRA bit 9 ~ bit 8
TM1BL Register
Bit
Register
Name
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 7~0
TM1BL: TM1 CCRB Low Byte Register bit 7 ~ bit 0
TM1 10-bit CCRB bit 7 ~ bit 0
TM1BH Register
Bit
Register
Name
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 1~0
TM1BH: TM1 CCRB High Byte Register bit 1 ~ bit 0
TM1 10-bit CCRB bit 9 ~ bit 8
TM1C0 Register
7
6
5
4
3
2
1
0
Name
T1PAU
T1CK2
T1CK1
T1CK0
T1ON
T1RP2
T1RP1
T1RP0
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
Rev. 1.30
Bit
Register
Name
T1PAU: TM1 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.
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March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Rev. 1.30
Bit 6~4
T1CK2~T1CK0: Select TM1 Counter clock
000: fSYS/4
001: fSYS
010: fH/16
011: fH/64
100: fSUB
101: Undefined, can not be selected.
110: TCK1 rising edge clock
111: TCK1 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 fSUB are other internal clocks, the details of which can
be found in the oscillator section.
Bit 3
T1ON: TM1 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 while 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 T1OC bit, when the T1ON bit changes from
low to high.
Bit 2~0
T1RP2~T1RP0: TM1 CCRP 3-bit register, compare with the TM1 counter bit 9~bit 7
Comparator P Match Period
000: 1024 TM1 clocks
001: 128 TM1 clocks
010: 256 TM1 clocks
011: 384 TM1 clocks
100: 512 TM1 clocks
101: 640 TM1 clocks
110: 768 TM1 clocks
111: 896 TM1 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 T1CCLR bit is set to
zero. Setting the T1CCLR 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.
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
TM1C1 Register
Rev. 1.30
Bit
Register
Name
7
6
5
4
3
2
1
0
Name
T1AM1
T1AM0
T1AIO1
T1AIO0
T1AOC
T1APOL
T1CDN
T1CCLR
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
R/W
POR
0
0
0
0
0
0
0
0
Bit 7~6
T1AM1~T1AM0: Select TM1 CCRA Operation 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 T1AM1 and
T1AM0 bits. In the Timer/Counter Mode, the TM output pin control must be disabled.
Bit 5~4
T1AIO1~T1AIO0: Select TP1A_0, TP1A_1 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 TP1A_0, TP1A_1
01: Input capture at falling edge of TP1A_0, TP1A_1
01: Input capture at falling/rising edge of TP1A_0, TP1A_1
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 T1AIO1 and T1AIO0 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 T1AOC bit in the TM1C1 register. Note that the output
level requested by the T1AIO1 and T1AIO0 bits must be different from the initial
value setup using the T1AOC 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 T1ON bit from low to high.
In the PWM Mode, the T1AIO1 and T1AIO0 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 T1AIO1 and T1AIO0 bits only after the TM has been switched off. Unpredictable
PWM outputs will occur if the T1AIO1 and T1AIO0 bits are changed when the TM is
running
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March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Rev. 1.30
Bit 3
T1AOC: TP1A_0, TP1A_1output 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 2
T1APOL: TP1A_0, TP1A_1output Polarity control
0: Non-invert
1: Invert
This bit controls the polarity of the TP1A_0 or TP1A_1 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 1
T1CDN: TM1 Counter count up or down flag
0: Count Up
1: Count Down
Bit 0
T1CCLR: Select TM1 Counter clear condition
0: TM1 Comparator P match
1: TM1 Comparator A match
This bit is used to select the method which clears the counter. Remember that
the Enhanced TM contains three comparators, Comparator A, Comparator B and
Comparator P, but only Comparator A or Comparator P can be selected to clear the
internal counter. With the T1CCLR 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 T1CCLR bit is not used in the Single Pulse or Input
Capture Mode.
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
TM1C2 Register
Rev. 1.30
Bit
Register
Name
7
6
5
4
3
2
Name
T1BM1
T1BM0
T1BIO1
T1BIO0
T1BOC
T1BPOL
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
1
0
T1PWM1 T1PWM0
Bit 7~6
T1BM1~T1BM0: Select TM1 CCRB Operation 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 T1BM1 and
T1BM0 bits. In the Timer/Counter Mode, the TM output pin control must be disabled.
Bit 5~4
T1BIO1~T1BIO0: Select TP1B_0, TP1B_1, TP1B_2 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 TP1B_0, TP1B_1, TP1B_2
01: Input capture at falling edge of TP1B_0, TP1B_1, TP1B_2
01: Input capture at falling/rising edge of TP1B_0, TP1B_1, TP1B_2
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 T1BIO1 and T1BIO0 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 T1BOC bit in the TM1C2 register. Note that the output
level requested by the T1BIO1 and T1BIO0 bits must be different from the initial
value setup using the T1BOC 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 T1ON bit from low to high.
In the PWM Mode, the T1BIO1 and T1BIO0 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 T1BIO1 and T1BIO0 bits only after the TM has been switched off. Unpredictable
PWM outputs will occur if the T1BIO1 and T1BIO0 bits are changed when the TM is
running
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March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Rev. 1.30
Bit 3
T1BOC: TP1B_0, TP1B_1, TP1B_2 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 2
T1BPOL: TP1B_0, TP1B_1, TP1B_2 output Polarity control
0: Non-invert
1: Invert
This bit controls the polarity of the TP1B_0, TP1B_1, TP1B_2 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 1~0
T1PWM1~T1PWM0: Select PWM Mode
00: Edge aligned
01: Centre aligned, compare match on count up
10: Centre aligned, compare match on count down
11: Centre aligned, compare match on count up or down
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March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Enhanced Type TM Operation Modes
The Enhanced 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 TnAM1 and TnAM0 bits in the TMnC1, and the TnBM1 and
TnBM0 bits in the TMnC2 register.
ETM Operating Mode
CCRA
CCRA Timer/
Compare Match
Counter Mode
Output Mode
CCRB PWM
Output Mode
CCRB
Single Pulse
Output Mode
CCRB Input
Capture Mode
—
—
—
—
CCRB Compare Match
Output Mode
√
CCRB Timer/Counter Mode
—
√
—
—
—
CCRB PWM Output Mode
—
—
√
—
—
CCRB Single Pulse Output
Mode
—
—
—
√
—
CCRB Input Capture Mode
—
—
—
—
√
“√”: permitted.
“—”: not permitted
Compare Match Output Mode
To select this mode, bits TnAM1, TnAM0 and TnBM1, TnBM0 in the TMnC1/TMnC2 registers
should be all cleared to zero. 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 TnCCLR bit is low, there are two ways in which the counter
can be cleared. One is when a compare match occurs from Comparator P, the other is when the
CCRP bits are all zero which allows the counter to overflow. Here both the TnAF and TnPF interrupt
request flags for Comparator A and Comparator P respectively, will both be generated.
If the TnCCLR bit in the TMnC1 register is high then the counter will be cleared when a compare
match occurs from Comparator A. However, here only the TnAF interrupt request flag will be
generated even if the value of the CCRP bits is less than that of the CCRA registers. Therefore when
TnCCLR is high no TnPF interrupt request flag will 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 TnAF or TnBF interrupt
request flag is generated after a compare match occurs from Comparator A or Comparator B. The
TnPF interrupt request flag, generated from a compare match from Comparator P, will have no
effect on the TM output pin. The way in which the TM output pin changes state is determined by the
condition of the TnAIO1 and TnAIO0 bits in the TMnC1 register for ETM CCRA, and the TnBIO1
and TnBIO0 bits in the TMnC2 register for ETM CCRB. The TM output pin can be selected using
the TnAIO1, TnAIO0 bits (for the TPnA_0 or TPnA_1 pin) and TnBIO1, TnBIO0 bits (for the
TPnB_0, TPnB_1 or TPnB_2 pins) to go high, to go low or to toggle from its present condition
when a compare match occurs from Comparator A or a compare match occurs from Comparator B.
The initial condition of the TM output pin, which is setup after the TnON bit changes from low to
high, is setup using the TnAOC or TnBOC bit for TPnA_0, TPnA_1 or TPnB_0, TPnB_1, TPnB_2
output pins. Note that if the TnAIO1, TnAIO0 and TnBIO1, TnBIO0 bits are zero then no pin
change will take place.
Rev. 1.30
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March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Counter overflow
Counter Value
CCRP=0
0x3FF
TnCCLR = 0; TnAM [1:0] = 00
CCRP > 0
Counter cleared by CCRP value
CCRP > 0
Counter
Restart
Resume
CCRP
Pause
CCRA
Stop
Time
TnON
TnPAU
TnAPOL
CCRP Int.
Flag TnPF
CCRA Int.
Flag TnAF
TPnA O/P
Pin
Output pin set to
initial Level Low
if TnAOC=0
Output not affected by TnAF
flag. Remains High until reset
by TnON bit
Output Toggle with
TnAF flag
Here TnAIO [1:0] = 11
Toggle Output select
Note TnAIO [1:0] = 10
Active High Output select
Output Inverts
when TnAPOL is high
Output Pin
Reset to Initial value
Output controlled by
other pin-shared function
ETM CCRA Compare Match Output Mode – TnCCLR=0
Note: 1. With TnCCLR=0, a Comparator P match will clear the counter
2. The TPnA output pin is controlled only by the TnAF flag
3. The output pin is reset to its initial state by a TnON bit rising edge
Rev. 1.30
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March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Counter overflow
Counter Value
CCRP=0
0x3FF
TnCCLR = 0; TnBM [1:0] = 00
CCRP > 0
Counter cleared by CCRP value
CCRP > 0
Counter
Restart
Resume
CCRP
Pause
CCRB
Stop
Time
TnON
TnPAU
TnBPOL
CCRP Int.
Flag TnPF
CCRB Int.
Flag TnBF
TPnB O/P
Pin
Output pin set to
initial Level Low
if TnBOC=0
Output not affected by TnBF
flag. Remains High until reset
by TnON bit
Output Toggle with
TnBF flag
Here TnBIO [1:0] = 11
Toggle Output select
Note TnBIO [1:0] = 10
Active High Output select
Output Inverts
when TnBPOL is high
Output Pin
Reset to Initial value
Output controlled by
other pin-shared function
ETM CCRB Compare Match Output Mode – TnCCLR=0
Note: 1. With TnCCLR=0, a Comparator P match will clear the counter
2. The TPnB output pin is controlled only by the TnBF flag
3. The output pin is reset to its initial state by a TnON bit rising edge
Rev. 1.30
116
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Counter Value
TnCCLR = 1; TnAM [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
TnON
TnPAU
TnAPOL
No TnAF flag
generated on
CCRA overflow
CCRA Int.
Flag TnAF
CCRP Int.
Flag TnPF
TnPF not
generated
Output does
not change
TPnA O/P
Pin
Output pin set to
initial Level Low
if TnAOC=0
Output not affected by
TnAF flag. Remains High
until reset by TnON bit
Output Toggle with
TnAF flag
Here TnAIO [1:0] = 11
Toggle Output select
Note TnAIO [1:0] = 10
Active High Output select
Output Inverts
when TnAPOL is high
Output Pin
Reset to Initial value
Output controlled by
other pin-shared function
ETM CCRA Compare Match Output Mode – TnCCLR=1
Note: 1. With TnCCLR=1, a Comparator A match will clear the counter
2. The TPnA output pin is controlled only by the TnAF flag
3. The TPnA output pin is reset to its initial state by a TnON bit rising edge
4. The TnPF flag is not generated when TnCCLR=1
Rev. 1.30
117
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Counter Value
TnCCLR = 1; TnBM [1:0] = 00
CCRA = 0
Counter overflow
CCRA > 0 Counter cleared by CCRA value
0x3FF
Resume
CCRA
Pause
CCRA=0
Stop
Counter Restart
CCRB
Time
TnON
TnPAU
TnBPOL
No TnAF flag
generated on
CCRA overflow
CCRA Int.
Flag TnAF
CCRB Int.
Flag TnBF
TPnB O/P
Pin
Output pin set to
initial Level Low
if TnBOC=0
Output Toggle with
TnBF flag
Here TnBIO [1:0] = 11
Toggle Output select
Output not affected by
TnBF flag. Remains High
until reset by TnON bit
Note TnBIO [1:0] = 10
Active High Output select
Output Inverts
when TnBPOL is high
Output Pin
Reset to Initial value
Output controlled by
other pin-shared function
ETM CCRB Compare Match Output Mode – TnCCLR=1
Note: 1. With TnCCLR=1, a Comparator A match will clear the counter
2. The TPnB output pin is controlled only by the TnBF flag
3. The TPnB output pin is reset to its initial state by a TnON bit rising edge
4. The TnPF flag is not generated when TnCCLR=1
Rev. 1.30
118
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Timer/Counter Mode
To select this mode, bits TnAM1, TnAM0 and TnBM1, TnBM0 in the TMnC1 and TMnC2 register
should all be set high. 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, the required bit pairs, TnAM1, TnAM0 and TnBM1, TnBM0 should be set
to 10 respectively and also the TnAIO1, TnAIO0 and TnBIO1, TnBIO0 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 TnCCLR bit is used to determine in which
way the PWM period is controlled. With the TnCCLR bit set high, the PWM period can be finely
controlled using the CCRA registers. In this case the CCRB registers are used to set the PWM duty
value (for TPnB output pins). The CCRP bits are not used and TPnA output pins are not used. The
PWM output can only be generated on the TPnB output pins. With the TnCCLR bit cleared to zero,
the PWM period is set using one of the eight values of the three CCRP bits, in multiples of 128.
Now both CCRA and CCRB registers can be used to setup different duty cycle values to provide
dual PWM outputs on their relative TPnA and TPnB pins.
The TnPWM1 and TnPWM0 bits determine the PWM alignment type, which can be either edge
or centre type. In edge alignment, the leading edge of the PWM signals will all be generated
concurrently when the counter is reset to zero. With all power currents switching on at the same
time, this may give rise to problems in higher power applications. In centre alignment the centre
of the PWM active signals will occur sequentially, thus reducing the level of simultaneous power
switching currents.
Interrupt flags, one for each of the CCRA, CCRB and CCRP, will be generated when a compare
match occurs from either the Comparator A, Comparator B or Comparator P. The TnAOC and
TnBOC bits in the TMnC1 and TMnC2 register are used to select the required polarity of the PWM
waveform while the two TnAIO1, TnAIO0 and TnBIO1, TnBIO0 bits pairs are used to enable the
PWM output or to force the TM output pin to a fixed high or low level. The TnAPOL and TnBPOL
bit are used to reverse the polarity of the PWM output waveform.
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
ETM, PWM Mode, Edge-aligned Mode, TnCCLR=0
CCRP
001b
010b
011b
100b
101b
110b
111b
000b
Period
128
256
384
512
640
768
896
1024
A Duty
CCRA
B Duty
CCRB
If fSYS = 16MHz, TM clock source select fSYS/4, CCRP = 100b, CCRA = 128 and CCRB = 256,
The TP1A PWM output frequency = (fSYS/4) / 512 = fSYS/2048 = 7.8125kHz, duty = 128/512 = 25%.
The TP1B_n PWM output frequency = (fSYS/4) / 512 = fSYS/2048 = 7.8125kHz, duty = 256/512 = 50%.
If the Duty value defined by CCRA or CCRB register is equal to or greater than the Period value,
then the PWM output duty is 100%.
ETM, PWM Mode, Edge-aligned Mode, TnCCLR=1
CCRA
1
2
3
511
512
1021
1022
1023
Period
1
2
3
511
512
1021
1022
1023
B Duty
CCRB
ETM, PWM Mode, Center-aligned Mode, TnCCLR=0
CCRP
001b
010b
011b
100b
101b
110b
111b
000b
Period
256
512
768
1024
1280
1536
1792
2046
A Duty
(CCRA × 2) - 1
B Duty
(CCRB × 2) - 1
ETM, PWM Mode, Center-aligned Mode, TnCCLR=1
CCRA
1
2
3
511
512
1021
1022
1023
Period
2
4
6
1022
1024
2042
2044
2046
B Duty
Rev. 1.30
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120
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Counter Value
TnCCLR = 0;
TnAM [1:0] = 10, TnBM [1:0] = 10;
TnPWM [1:0] = 00
Counter Cleared by CCRP
CCRP
CCRA
Pause
Resume
Stop
CCRB
Counter
Restart
Time
TnON
TnPAU
TnAPOL
CCRA Int.
Flag TnAF
CCRB Int.
Flag TnBF
CCRP Int.
Flag TnPF
TPnA Pin
(TnAOC=1)
Duty Cycle
set by CCRA
TPnB Pin
Duty Cycle
set by CCRA
Duty Cycle
set by CCRA
Output Inverts
when TnAPOL
is high
(TnBOC=1)
TPnB Pin
(TnBOC=0)
Duty Cycle
set by CCRB
Output controlled by
other pin-shared function
Output Pin
Reset to Initial value
PWM Period set by CCRP
ETM PWM Mode – Edge Aligned
Note: 1. Here TnCCLR=0 therefore CCRP clears the counter and determines the PWM period
2. The internal PWM function continues running even when TnAIO [1:0] (or TnBIO [1:0])
= 00 or 01
3. CCRA controls the TPnA PWM duty and CCRB controls the TPnB PWM duty
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HT66F24D/HT66F25D/HT66F26D
Counter Value
TnCCLR = 1; TnBM [1:0] = 10;
TnPWM [1:0] = 00
Counter Cleared by CCRA
CCRA
Pause
Resume
Stop
CCRB
Counter
Restart
Time
TnON
TnPAU
TnBPOL
CCRP Int.
Flag TnPF
CCRB Int.
Flag TnBF
TPnB Pin
(TnBOC=1)
TPnB Pin
(TnBOC=0)
Duty Cycle
set by CCRB
Output controlled by
other pin-shared function
PWM Period set by CCRA
Output Pin
Reset to
Initial value
Output Inverts
when TnBPOL
is high
ETM PWM Mode – Edge Aligned
Note: 1. Here TnCCLR=1 therefore CCRA clears the counter and determines the PWM period
2. The internal PWM function continues running even when TnBIO [1:0] = 00 or 01
3. CCRA controls the TPnB PWM period and CCRB controls the TPnB PWM duty
4. Here the TM pin control register should not enable the TPnA pin as a TM output pin.
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HT66F24D/HT66F25D/HT66F26D
TnCCLR = 0;
TnAM [1:0] = 10, TnBM [1:0] = 10;
TnPWM [1:0] = 11
Counter Value
CCRP
Resume
CCRA
Stop
Counter
Restart
Pause
CCRB
Time
TnON
TnPAU
TnAPOL
CCRA Int.
Flag TnAF
CCRB Int.
Flag TnBF
CCRP Int.
Flag TnPF
TPnA Pin
(TnAOC=1)
TPnB Pin
Duty Cycle set by CCRA
Output Inverts
when TnAPOL
is high
(TnBOC=1)
TPnB Pin
(TnBOC=0)
Duty Cycle set by CCRB
Output controlled by
Other pin-shared function
PWM Period set by CCRP
Output Pin
Reset to Initial value
ETM PWM Mode – Centre Aligned
Note: 1. Here TnCCLR=0 therefore CCRP clears the counter and determines the PWM period
2. TnPWM [1:0] =11 therefore the PWM is centre aligned
3. The internal PWM function continues running even when TnAIO [1:0] (or TnBIO [1:0])
= 00 or 01
4. CCRA controls the TPnA PWM duty and CCRB controls the TPnB PWM duty
5. CCRP will generate an interrupt request when the counter decrements to its zero value
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Counter Value
TnCCLR = 1; TnBM [1:0] = 10;
TnPWM [1:0] = 11
CCRA
Resume
Stop
Counter
Restart
Pause
CCRB
Time
TnON
TnPAU
TnBPOL
CCRA Int.
Flag TnAF
CCRB Int.
Flag TnBF
CCRP Int.
Flag TnPF
TPnB Pin
(TnBOC=1)
TPnB Pin
(TnBOC=0)
Output controlled
Output Inverts
by other pin-shared
when TnBPOL is high
function
Output Pin
Reset to Initial value
Duty Cycle set by CCRB
PWM Period set by CCRA
ETM PWM Mode – Centre Aligned
Note: 1. Here TnCCLR=1 therefore CCRA clears the counter and determines the PWM period
2. TnPWM [1:0] =11 therefore the PWM is centre aligned
3. The internal PWM function continues running even when TnBIO [1:0] = 00 or 01
4. CCRA controls the TPnB PWM period and CCRB controls the TPnB PWM duty
5. CCRP will generate an interrupt request when the counter decrements to its zero value
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Single Pulse Output Mode
To select this mode, the required bit pairs, TnAM1, TnAM0 and TnBM1, TnBM0 should be set to
10 respectively and also the corresponding TnAIO1, TnAIO0 and TnBIO1, TnBIO0 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 TPnA output leading edge is a low to high transition of the TnON bit, which
can be implemented using the application program. The trigger for the pulse TPnB output leading
edge is a compare match from Comparator B, which can be implemented using the application
program. However in the Single Pulse Mode, the TnON bit can also be made to automatically
change from low to high using the external TCKn pin, which will in turn initiate the Single Pulse
output of TPnA. When the TnON bit transitions to a high level, the counter will start running and
the pulse leading edge of TPnA will be generated. The TnON bit should remain high when the pulse
is in its active state. The generated pulse trailing edge of TPnA and TPnB will be generated when
the TnON 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 TnON bit and thus
generate the Single Pulse output trailing edge of TPnA and TPnB. In this way the CCRA value can
be used to control the pulse width of TPnA. The CCRA-CCRB value can be used to control the
pulse width of TPnB. A compare match from Comparator A and Comparator B will also generate
TM interrupts. The counter can only be reset back to zero when the TnON bit changes from low to
high when the counter restarts. In the Single Pulse Mode CCRP is not used. The TnCCLR bit is also
not used.
Counter Value
CCRA
CCRB
Time
0
S/W Command
SET“TnON”
or
TCKn Pin
Transition
CCRA
Leading Edge
CCRA
Trailing Edge
TnON bit
0à1
TnON bit
1à0
S/W Command
CLR“TnON”
or
CCRA Compare
Match
TPnA Output Pin
Pulse Width = CCRA Value
TPnB Output Pin
Pulse Width = (CCRA-CCRB) Value
CCRB Compare
Match
TnON = 1
TnON bit
1à0
CCRB
Leading Edge
CCRB
Trailing Edge
S/W Command
CLR“TnON”
or
CCRA Compare
Match
Single Pulse Generation
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Counter Value
TnAM [1:0] = 10, TnBM [1:0] = 10;
TnAIO [1:0] = 11, TnBIO [1:0] = 11
Counter stopped
by CCRA
CCRA
Pause
Counter Stops
by software
Resume
CCRB
Counter Reset
when TnON
returns high
Time
TnON
Software
Trigger
Cleared by
CCRA match
Auto. set by
TCKn pin
TCKn pin
Software
Trigger
Software
Software Trigger
Clear
Software
Trigger
TCKn pin
Trigger
TnPAU
TnAPOL
TnBPOL
CCRB Int.
Flag TnBF
CCRA Int.
Flag TnAF
TPnA Pin
(TnAOC=1)
TPnA Pin
Pulse Width
set by CCRA
(TnAOC=0)
Output Inverts
when TnAPOL=1
TPnB Pin
(TnBOC=1)
TPnB Pin
Pulse Width set
by (CCRA-CCRB)
(TnBOC=0)
Output Inverts
when TnBPOL=1
Single Pulse Mode
Note: 1. Counter stopped by CCRA
2. CCRP is not used
3. The pulse is triggered by the TCKn pin or by setting the TnON bit high
4. A TCKn pin active edge will automatically set by the TnON bit high.
5. In the Single Pulse Mode, TnAIO [1:0] and TnBIO [1:0] must be set to “11” and can not
be changed.
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Capture Input Mode
To select this mode bits TnAM1, TnAM0 and TnBM1, TnBM0 in the TMnC1 and TMnC2 registers
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 TPnA_0, TPnA_1 and TPnB_0, TPnB_1,
TPnB_2 pins, 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 TnAIO1, TnAIO0 and TnBIO1, TnBIO0
bits in the TMnC1 and TMnC2 registers. The counter is started when the TnON bit changes from
low to high which is initiated using the application program.
When the required edge transition appears on the TPnA_0, TPnA_1 and TPnB_0, TPnB_1, TPnB_2
pins the present value in the counter will be latched into the CCRA and CCRB registers and a
TM interrupt generated. Irrespective of what events occur on the TPnA_0, TPnA_1 and TPnB_0,
TPnB_1, TPnB_2 pins the counter will continue to free run until the TnON 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
TnAIO1, TnAIO0 and TnBIO1, TnBIO0 bits can select the active trigger edge on the TPnA_0,
TPnA_1 and TPnB_0, TPnB_1, TPnB_2 pins to be a rising edge, falling edge or both edge types.
If the TnAIO1, TnAIO0 and TnBIO1, TnBIO0 bits are both set high, then no capture operation will
take place irrespective of what happens on the TPnA_0, TPnA_1 and TPnB_0, TPnB_1, TPnB_2
pins, however it must be noted that the counter will continue to run.
As the TPnA_0, TPnA_1 and TPnB_0, TPnB_1, TPnB_2 pins are pin shared with other functions,
care must be taken if the TM is in the Capture Input 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
TnCCLR, TnAOC, TnBOC, TnAPOL and TnBPOL bits are not used in this mode.
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Counter Value
TnAM [1:0] = 01
Counter cleared
by CCRP
Counter Counter
Stop
Reset
CCRP
YY
Pause
Resume
XX
Time
TnON
TnPAU
Active
edge
TM capture
pin TPnA
Active
edge
Active edge
CCRA Int.
Flag TnAF
CCRP Int.
Flag TnPF
CCRA
Value
XX
TnAIO [1:0]
Value
00 – Rising edge
YY
01 – Falling edge
XX
10 – Both edges
YY
11 – Disable Capture
ETM CCRA Capture Input Mode
Note: 1. TnAM [1:0] = 01 and active edge set by the TnAIO [1:0] bits
2. The TM Capture input pin active edge transfers the counter value to CCRA
3. TnCCLR bit not used
4. No output function – TnAOC and TnAPOL bits 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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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Counter Value
TnBM [1:0] = 01
Counter cleared
by CCRP
Counter Counter
Stop
Reset
CCRP
YY
Pause
Resume
XX
Time
TnON
TnPAU
TM capture
pin TPnB_x
Active
edge
Active
edge
Active edge
CCRB Int.
Flag TnBF
CCRP Int.
Flag TnPF
CCRB
Value
XX
TnBIO [1:0]
Value
00 – Rising edge
YY
01 – Falling edge
XX
10 – Both edges
YY
11 – Disable Capture
ETM CCRB Capture Input Mode
Note: 1. TnBM [1:0] = 01 and active edge set by the TnBIO [1:0] bits
2. The TM Capture input pin active edge transfers the counter value to CCRB
3. TnCCLR bit not used
4. No output function – TnBOC and TnBPOL bits 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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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
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 devices contain a multi-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.
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  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
ADRL (ADRFS=0)
Bit
7
6
5
4
3
2
1
0
D3
D2
D1
D0
—
—
—
—
D0
ADRL (ADRFS=1)
D7
D6
D5
D4
D3
D2
D1
ADRH (ADRFS=0)
D11
D10
D9
D8
D7
D6
D5
D4
ADRH (ADRFS=1)
—
—
—
—
D11
D10
D9
D8
ADCR0
START
EOCB
ADOFF
ADRFS
—
ACS2
ACS1
ACS0
ADCR1
ACS4
VBGEN
—
VREFS
—
ADCK2
ADCK1
ADCK0
ACERL
ACE7
ACE6
ACE5
ACE4
ACE3
ACE2
ACE1
ACE0
A/D Converter Register List
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
A/D Converter Data Registers – ADRL, ADRH
As the devices contain an internal 12-bit A/D converter, they require 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.
ADRH
ADRFS
ADRL
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
0
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
0
0
0
0
1
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 and 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 ACS2~ACS0 bits in the ADCR0 register and ACS4 bit is the ADCR1 register
define the ADC input channel number. As the device contains only one actual analog to digital
converter hardware circuit, each of the individual 4 analog inputs must be routed to the converter. It
is the function of the ACS4 and ACS2~ACS0 bits to determine which analog channel input pins or
internal reference voltage, VBG, is actually connected to the internal A/D converter.
The ACERL control register contains the ACER7~ACER0 bits which determine which pins on I/O
ports 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
Rev. 1.30
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 7
START: 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 6
EOCB: 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 5
ADOFF: A/D module on/off control bit
0: A/D module power on
1: A/D 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 4
ADRFS: A/D Data Format control bit
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.
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
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
ADCR1 Register
Rev. 1.30
Bit
7
6
5
4
3
2
1
0
Name
ACS4
VBGEN
—
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 7
ACS4: Select internal band gap reference voltage as ADC input Control
0: Disable
1: Enable
This bit enables the internal band gap reference voltage to be connected to the A/
D converter. The VBGEN bit must first have been set to enable the band gap circuit
reference voltage to be used by the A/D converter. When the ACS4 bit is set high, the
band gap reference voltage will be routed to the A/D converter and the other A/D input
channels disconnected.
Bit 6
VBGEN: Internal Band Gap reference voltage 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 band gap voltage can be used by the A/D converter. If
the band gap reference voltage is not used by the A/D converter and the LVR/LVD
function is disabled then the band gap reference circuit will be automatically switched
off to conserve power. When the band gap reference voltage is switched on for use by
the A/D converter, a time tBG should be allowed for the band gap circuit to stabilise
before implementing an A/D conversion.
Bit 5
unimplemented, read as “0”
Bit 4
VREFS: Select ADC reference voltage
0: Internal ADC power
1: VREF pin
This bit is used to select the reference voltage for the A/D converter. If the bit is high,
then the A/D converter reference voltage is supplied on the external VREF pin. If the
pin is low, then the internal reference is used which is taken from the power supply pin
VDD.
Bit 3
unimplemented, read as “0”
Bit 2~0
ADCK2~ADCK0: Select ADC converter clock source
000: fSYS
001: fSYS/2
010: fSYS/4
011: fSYS/8
100: fSYS/16
101: fSYS/32
110: fSYS/64
111: undefined, can not be used.
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 7
ACE7: Define I/O pin is A/D input or not
0: Not A/D input
1: A/D input, AN7
Bit 6
ACE6: Define I/O pin is A/D input or not
0: Not A/D input
1: A/D input, AN6
Bit 5
ACE5: Define I/O pin is A/D input or not
0: Not A/D input
1: A/D input, AN5
Bit 4
ACE4: Define I/O pin is A/D input or not
0: Not A/D input
1: A/D input, AN4
Bit 3
ACE3: Define I/O pin is A/D input or not
0: Not A/D input
1: A/D input, AN3
Bit 2
ACE2: Define I/O pin is A/D input or not
0: Not A/D input
1: A/D input, AN2
Bit 1
ACE1: Define I/O pin is A/D input or not
0: Not A/D input
1: A/D input, AN1
Bit 0
ACE0: Define I/O pin 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, tADCK, is from 0.5μs to 10μs, care must be
taken for selected 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 (tADCK)
fSYS
ADCK2~
ADCK0 =
000 (fSYS)
ADCK2~
ADCK0 =
001(fSYS/2)
ADCK2~
ADCK0 =
010(fSYS/4)
ADCK2~
ADCK2~
ADCK2~
ADCK2~
ADCK0 =
ADCK0 =
ADCK0 =
ADCK0 =
011(fSYS/8) 100(fSYS/16) 101(fSYS/32) 110(fSYS/64)
1MHz
1µs
2µs
4µs
8µs
16µs*
32µs*
ADCK2~
ADCK0 =
111
64µs*
Undefined
Undefined
2MHz
500ns
1µs
2µs
4µs
8µs
16µs*
32µs*
4MHz
250ns*
500ns
1µs
2µs
4µs
8µs
16µs*
Undefined
8MHz
125ns*
250ns*
500ns
1µs
2µs
4µs
8µs
Undefined
12MHz
83ns*
167ns*
333ns*
667ns
1.33µs
2.67µs
5.33µs
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 register, 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, VDD, or from an external reference sources supplied on pin VREF. The desired selection
is made using the VREFS bit. As the VREF pin is pin-shared with other functions, when the VREFS
bit is set high, the VREF pin function will be selected and other pin functions will be disabled
automatically.
A/D Input Pins
All of the A/D analog input pins are pin-shared with the I/O pins as well as other functions.
The ACE7~ACE0 bits in the ACERL register determines 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 PAC 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.
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The A/D converter has its own reference voltage pin 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. The analog input values must not be allowed to exceed the value of VREF.
        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 and ACS2~ACS0 bits which are also contained in the ADCR1 and ADCR0 registers.
• 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 to high to do this.
• 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 to low again. Note that this bit should have been
originally cleared to 0.
• 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 ADCR register is used, the interrupt enable step above can be omitted.
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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 16 tADCK where tADCK is equal to the A/D clock period.
‚ ‚
ƒ  €

€    
                   ­    A/D Conversion Timing
Programming Considerations
During microcontroller operates 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 devices contain 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 VDD or VREF voltage, this gives a single
bit analog input value of VDD or VREF divided by 4096.
1 LSB =
(VDD 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 × (VDD 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 VDD level.
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    
 
      Ideal A/D Transfer Function
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 1: using an EOCB polling method to detect the end of conversion
clr
ADE; disable ADC interrupt
mova,03H
mov ADCR1,a ; select fSYS/8 as A/D clock and switch off the band gap
; reference voltage
clr ADOFF
mov a,0Fh ; setup ACERL register to configure pins AN0~AN3
mov ACERL,a
mova,00h
mov ADCR0,a ; enable and connect AN0 channel to A/D converter
:
start_conversion:
clr START ; high pulse on start bit to initiate conversion
set START ; reset A/D
clr START ; start A/D
polling_EOC:
sz EOCB ; poll the ADCR0 register EOCB bit to detect end of A/D conversion
jmp polling_EOC ; continue polling
mov a,ADRL ; read low byte conversion result value
mov ADRL_buffer,a ; save result to user defined register
mov a,ADRH ; read high byte conversion result value
mov ADRH_buffer,a ; save result to user defined register
:
jmp start_conversion ; start next a/d conversion
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Example 2: using the interrupt method to detect the end of conversion
clr
ADE; disable ADC interrupt
mova,03H
mov ADCR1,a ; select fSYS/8 as A/D clock and switch off the band gap reference voltage
clr ADOFF
mov a,0Fh ; setup ACERL register to configure pins AN0~AN3
mov ACERL,a
mova,00h
mov ADCR0,a ; enable and connect AN0 channel to A/D converter
Start_conversion:
clr START ; high pulse on START bit to initiate conversion
set START ; reset A/D
clr START ; start A/D
clr ADF ; clear ADC interrupt request flag
set
ADE; enable ADC interrupt
set EMI ; enable global interrupt
:
; ADC interrupt service routine
ADC_ISR:
mov acc_stack,a ; save ACC to user defined memory
mov a,STATUS
mov status_stack,a ; save STATUS to user defined memory
:
mov a,ADRL ; read low byte conversion result value
mov adrl_buffer,a ; save result to user defined register
mov a,ADRH ; read high byte conversion result value
mov adrh_buffer,a ; save result to user defined register
:
EXIT_INT_ISR:
mov a,status_stack
mov STATUS,a ; restore STATUS from user defined memory
mov a,acc_stack ; restore ACC from user defined memory
reti
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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 several external
interrupt and internal interrupts functions. The external interrupts are generated by the action of the
external INT0 and INT1 pins while the internal interrupts are generated by various internal functions
such as the TMs, Time Base, LVD 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~INTC2 registers which setup the primary interrupts, the second
is the MFI0~MFI3 registers which setup the Multi-function interrupts. Finally there is an INTEG
register 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.
Function
Enable Bit
Request Flag
EMI
—
—
INTn Pins
INTnE
INTnF
n = 0 or 1
Multi-function
MFnE
MFnF
n = 0 ~3
A/D converter
ADE
ADF
—
Time Base
TBnE
TBnF
n = 0 or 1
Global
Notes
LVD
LVE
LVF
—
EEPROM
DEE
DEF
—
TnPE
TnPF
TnAE
TnAF
TnBE
TnBF
TM
n = 0 or 1 or 2
n=1
Interrupt Register Bit Naming Conventions
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HT66F24D Interrupt Register List
Bit
Register
Name
7
6
5
4
3
2
1
0
INTEG
—
—
—
—
INT1S1
INT1S0
INT0S1
INT0S0
INTC0
—
MF0F
INT1F
INT0F
MF0E
INT1E
INT0E
EMI
INTC1
TB1F
TB0F
ADF
MF1F
TB1E
TB0E
ADE
MF1E
INTC2
—
—
—
MF2F
—
—
—
MF2E
MFI0
—
—
T0AF
T0PF
—
—
T0AE
T0PE
MFI1
—
—
T1AF
T1PF
—
—
T1AE
T1PE
MFI2
—
—
DEF
LVF
—
—
DEE
LVE
HT66F25D Interrupt Register List
Bit
Register
Name
7
6
5
4
3
2
1
0
INTEG
—
—
—
—
INT1S1
INT1S0
INT0S1
INT0S0
INTC0
—
MF0F
INT1F
INT0F
MF0E
INT1E
INT0E
EMI
INTC1
TB1F
TB0F
ADF
MF1F
TB1E
TB0E
ADE
MF1E
INTC2
—
—
—
MF2F
—
—
—
MF2E
MFI0
—
—
T0AF
T0PF
—
—
T0AE
T0PE
MFI1
—
T1BF
T1AF
T1PF
—
T1BE
T1AE
T1PE
MFI2
—
—
DEF
LVF
—
—
DEE
LVE
HT66F26D Interrupt Register List
Bit
Register
Name
7
6
5
4
3
2
1
0
INTEG
—
—
—
—
INT1S1
INT1S0
INT0S1
INT0S0
INTC0
—
MF0F
INT1F
INT0F
MF0E
INT1E
INT0E
EMI
INTC1
TB1F
TB0F
ADF
MF1F
TB1E
TB0E
ADE
MF1E
INTC2
—
—
MF3F
MF2F
—
—
MF3E
MF2E
MFI0
—
—
T0AF
T0PF
—
—
T0AE
T0PE
MFI1
—
T1BF
T1AF
T1PF
—
T1BE
T1AE
T1PE
MFI2
—
—
DEF
LVF
—
—
DEE
LVE
MFI3
—
—
T2AF
T2PF
—
—
T2AE
T2PE
7
6
5
4
3
2
1
0
INTEG Register
Bit
Name
—
—
—
—
INT1S1
INT1S0
INT0S1
INT0S0
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
INT1S1~INT1S0: interrupt edge control for INT1 pin
00: disable
01: rising edge
10: falling edge
01: both rising and falling edges
INT0S1~INT0S0: interrupt edge control for INT0 pin
00: disable
01: rising edge
10: falling edge
01: both rising and falling edges
Bit 1~0
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INTC0 Register
Rev. 1.30
Bit
7
6
5
4
3
2
1
0
Name
—
MF0F
INT1F
INT0F
MF0E
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 6
MF0F: Multi-function 0 Interrupt request flag
0: no request
1: interrupt request
Bit 5
INT1F: INT1 interrupt request flag
0: no request
1: interrupt request
Bit 4
INT0F: INT0 interrupt request flag
0: no request
1: interrupt request
Bit 3
MF0E: Multi-function 0 Interrupt control
0: disable
1: enable
Bit 2
INT1E: INT1 interrupt control
0: disable
1: enable
Bit 1
INT0E: INT0 interrupt control
0: disable
1: enable
Bit 0
EMI: Global interrupt control
0: disable
1: enable
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INTC1 Register
Bit
7
6
5
4
3
2
1
0
Name
TB1F
TB0F
ADF
MF1F
TB1E
TB0E
ADE
MF1E
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
TB1F: Time Base 1 Interrupt request flag
0: no request
1: interrupt request
Bit 6
TB0F: Time Base 0 Interrupt request flag
0: no request
1: interrupt request
Bit 5
ADF: A/D Converter interrupt request flag
0: no request
1: interrupt request
Bit 4
MF1F: Multi-function 1 Interrupt request flag
0: no request
1: interrupt request
Bit 3
TB1E: Time Base 1 Interrupt control
0: disable
1: enable
Bit 2
TB0E: Time Base 0 Interrupt control
0: disable
1: enable
Bit 1
ADE: A/D Converter interrupt control
0: disable
1: enable
Bit 0
MF1E: Multi-function 1 Interrupt control
0: disable
1: enable
INTC2 Register - HT66F24D/HT66F25D
Rev. 1.30
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
MF2F
—
—
—
MF2E
R/W
—
—
—
R/W
—
—
—
R/W
POR
—
—
—
0
—
—
—
0
Bit 7~5
unimplemented, read as “0”
Bit 4
MF2F: Multi-function 2 Interrupt request flag
0: no request
1: interrupt request
Bit 3~1
unimplemented, read as “0”
Bit 0
MF2E: Multi-function 2 Interrupt control
0: disable
1: enable
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INTC2 Register - HT66F26D
Bit
7
6
5
4
3
2
1
0
Name
—
—
MF3F
MF2F
—
—
MF3E
MF2E
R/W
—
—
R/W
R/W
—
—
R/W
R/W
POR
—
—
0
0
—
—
0
0
Bit 7~6
unimplemented, read as “0”
Bit 5
MF3F: Multi-function 3 Interrupt request flag
0: no request
1: interrupt request
Bit 4
MF2F: Multi-function 2 Interrupt request flag
0: no request
1: interrupt request
Bit 3~2
unimplemented, read as “0”
Bit 1
MF3E: Multi-function 3 Interrupt control
0: disable
1: enable
Bit 0
MF2E: Multi-function 2 Interrupt control
0: disable
1: enable
MFI0 Register
Rev. 1.30
Bit
7
6
5
4
3
2
1
0
Name
—
—
T0AF
T0PF
—
—
T0AE
T0PE
R/W
—
—
R/W
R/W
—
—
R/W
R/W
POR
—
—
0
0
—
—
0
0
Bit 7~6
unimplemented, read as “0”
Bit 5
T0AF: TM0 Comparator A match Interrupt request flag
0: no request
1: interrupt request
Bit 4
T0PF: TM0 Comparator P match Interrupt request flag
0: no request
1: interrupt request
Bit 3~2
unimplemented, read as “0”
Bit 1
T0AE: TM0 Comparator A match Interrupt control
0: disable
1: enable
Bit 0
T0PE: TM0 Comparator P match Interrupt control
0: disable
1: enable
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MFI1 Register - HT66F24D
Bit
7
6
5
4
3
2
1
0
Name
—
—
T1AF
T1PF
—
—
T1AE
T1PE
R/W
—
—
R/W
R/W
—
—
R/W
R/W
POR
—
—
0
0
—
—
0
0
Bit 7~6
unimplemented, read as “0”
Bit 5
T1AF: TM1 Comparator A match Interrupt request flag
0: no request
1: interrupt request
Bit 4
T1PF: TM1 Comparator P match Interrupt request flag
0: no request
1: interrupt request
Bit 3~2
unimplemented, read as “0”
Bit 1
T1AE: TM1 Comparator A match Interrupt control
0: disable
1: enable
Bit 0
T1PE: TM1 Comparator P match Interrupt control
0: disable
1: enable
MFI1 Register - HT66F25D/HT66F26D
Rev. 1.30
Bit
7
6
5
4
3
2
1
0
Name
—
T1BF
T1AF
T1PF
—
T1BE
T1AE
T1PE
R/W
—
R/W
R/W
R/W
—
R/W
R/W
R/W
POR
—
0
0
0
—
0
0
0
Bit 7
unimplemented, read as “0”
Bit 6
T1BF: TM1 Comparator B match Interrupt request flag
0: no request
1: interrupt request
Bit 5
T1AF: TM1 Comparator A match Interrupt request flag
0: no request
1: interrupt request
Bit 4
T1PF: TM1 Comparator P match Interrupt request flag
0: no request
1: interrupt request
Bit 3
unimplemented, read as “0”
Bit 2
T1BE: TM1 Comparator B match Interrupt control
0: disable
1: enable
Bit 1
T1AE: TM1 Comparator A match Interrupt control
0: disable
1: enable
Bit 0
T1PE: TM1 Comparator P match Interrupt control
0: disable
1: enable
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
MFI2 Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
DEF
LVF
—
—
DEE
LVE
R/W
—
—
R/W
R/W
—
—
R/W
R/W
POR
—
—
0
0
—
—
0
0
Bit 7~6
unimplemented, read as “0”
Bit 5
DEF: Data EEPROM Interrupt request flag
0: no request
1: interrupt request
Bit 4
LVF: LVD Interrupt request flag
0: no request
1: interrupt request
Bit 3~2
unimplemented, read as “0”
Bit 1
DEE: Data EEPROM Interrupt control
0: disable
1: enable
Bit 0
LVE: LVD interrupt control
0: disable
1: enable
MFI3 Register - HT66F26D
Rev. 1.30
Bit
7
6
5
4
3
2
1
0
Name
—
—
T2AF
T2PF
—
—
T2AE
T2PE
R/W
—
—
R/W
R/W
—
—
R/W
R/W
POR
—
—
0
0
—
—
0
0
Bit 7~6
unimplemented, read as “0”
Bit 5
T2AF: TM2 Comparator A match Interrupt request flag
0: no request
1: interrupt request
Bit 4
T2PF: TM2 Comparator P match Interrupt request flag
0: no request
1: interrupt request
Bit 3~2
unimplemented, read as “0”
Bit 1
T2AE: TM2 Comparator A match Interrupt control
0: disable
1: enable
Bit 0
T2PE: TM2 Comparator P match Interrupt control
0: disable
1: enable
146
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Interrupt Operation
When the conditions for an interrupt event occur, such as a TM Comparator P, Comparator A or
Comparator B 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.
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
EMI auto disabled in ISR
Legend
xxF
Request Flag, no auto reset in ISR
xxF
Request Flag, auto reset in ISR
xxE
Enable Bits
Interrupt
Name
INT0 Pin
Request
Flags
INT0F
Enable
Bits
INT0E
Master
Enable
EMI
Vector Priority
High
04H
TM0 P
T0PF
T0PE
INT1 Pin
INT1F
INT1E
EMI
08H
TM0 A
T0AF
T0AE
M. Funct. 0
MF0F
MF0E
EMI
0CH
TM1 P
T1PF
T1PE
M. Funct. 1
MF1F
MF1E
EMI
10H
TM1 A
T1AF
T1AE
A/D
ADF
ADE
EMI
14H
LVD
LVF
LVE
Time Base 0
TB0F
TB0E
EMI
18H
EEPROM
DEF
DEE
Time Base 1
TB1F
TB1E
EMI
1CH
M. Funct. 2
MF2F
MF2E
EMI
20H
Interrupts contained within
Multi-Function Interrupts
Low
Interrupt Scheme – HT66F24D
EMI auto disabled in ISR
Legend
xxF
Request Flag, no auto reset in ISR
xxF
Request Flag, auto reset in ISR
xxE
Enable Bits
Interrupt
Name
INT0 Pin
Request
Flags
INT0F
Enable
Bits
INT0E
Master
Enable
EMI
INT1 Pin
INT1F
INT1E
EMI
08H
Vector Priority
High
04H
TM0 P
T0PF
T0PE
TM0 A
T0AF
T0AE
M. Funct. 0
MF0F
MF0E
EMI
0CH
TM1 P
T1PF
T1PE
M. Funct. 1
MF1F
MF1E
EMI
10H
TM1 A
T1AF
T1AE
A/D
ADF
ADE
EMI
14H
TM1 B
T1BF
T1BE
Time Base 0
TB0F
TB0E
EMI
18H
LVD
LVF
LVE
EEPROM
DEF
DEE
Time Base 1
TB1F
TB1E
EMI
1CH
M. Funct. 2
MF2F
MF2E
EMI
20H
Interrupts contained within
Multi-Function Interrupts
Low
Interrupt Scheme – HT66F25D
Rev. 1.30
148
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
xxF
Legend
Request Flag� no auto �eset in ISR
xxF
Request Flag� auto �eset in ISR
xxE
Enable Bits
T�0 P
T0PF
T0PE
T�0 A
T0AF
T0AE
T�1 P
T1PF
T1PE
T�1 A
T1AF
T1AE
T�1 B
T1BF
T1BE
LVD
LVF
LVE
EEPRO�
DEF
DEE
T�� P
T�PF
T�PE
T�� A
T�AF
T�AE
Inte��upts �ontained wit�in
�ulti-Fun�tion Inte��upts
E�I auto disabled in ISR
Inte��upt
Name
INT0 Pin
Request
Flags
INT0F
Enable
Bits
INT0E
�aste�
Enable
E�I
Vector
INT1 Pin
INT1F
INT1E
E�I
08H
�. Fun�t. 0
�F0F
�F0E
E�I
0CH
�. Fun�t. 1
�F1F
�F1E
E�I
10H
A/D
ADF
ADE
E�I
14H
Time Base 0
TB0F
TB0E
E�I
18H
Time Base 1
TB1F
TB1E
E�I
1CH
�. Fun�t. �
�F�F
�F�E
E�I
�0H
�. Fun�t. 3
�F3F
�F3E
E�I
�4H
04H
P�io�ity
Hig�
Low
Interrupt Scheme – HT66F26D
External Interrupt
The external interrupts are controlled by signal transitions on the pins INT0~INT1. An external
interrupt request will take place when the external interrupt request flags, INT0F~INT1F, are set,
which will occur when a transition, whose type is chosen by the edge select bits, appears on the
external interrupt pins. To allow the program to branch to its respective interrupt vector address, the
global interrupt enable bit, EMI, and respective external interrupt enable bit, INT0E~INT1E, must
first be set. Additionally the correct interrupt edge type must be selected using the INTEG register to
enable the external interrupt function and to choose the trigger edge type. As the external interrupt
pins are pin-shared with I/O pins, they can only be configured as external interrupt pins if their
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 flags, INT0F~INT1F, will be automatically reset and the EMI bit will be
automatically cleared to disable other interrupts. Note that any pull-high resistor selections on the
external interrupt pins will remain valid even if the pin is used as an external interrupt input.
The INTEG register is 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 INTEG register can also be used to disable the external interrupt function.
Multi-function Interrupt
Within these devices there are up to nine 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, LVD or Data EEPROM Interrupts.
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
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, LVD or Data EEPROM Interrupts, will not be automatically reset and
must be manually reset by the application program.
A/D Converter 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 Interrupt
The function of the Time Base Interrupt is to provide regular time signal in the form of an internal
interrupt. It is controlled by the overflow signal from the respective timer function. When this
happens, the 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
the corresponding Time Base enable bit, 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.
Rev. 1.30
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
TBC Register
Bit
7
6
5
4
3
2
1
0
Name
TBON
TBCK
TB11
TB10
—
TB02
TB01
TB00
R/W
R/W
R/W
R/W
R/W
—
R/W
R/W
R/W
POR
0
0
1
1
—
1
1
1
Bit 7
TBON: Time Base control
0: Disable
1: Enable
Bit 6
TBCK: Time Base clock fTB selection
0: fSUB
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 3
unimplemented, read as “0”
Bit 2~0
TB02~TB00: Select Time Base 0 Time-out Period
000: 256/fTB
001: 512/fTB
010: 1024/fTB
011: 2048/fTB
100: 4096/fTB
101: 8192/fTB
110: 16384/fTB
111: 32768/fTB
÷�8 ~ ÷�1�
fSYS/4
LXT
LIRC
�
U
X
fSUB
Configu�ation
Option
Rev. 1.30
�
U
X
fTB
Time Base 0 Inte��upt
TB0�~TB00
÷� 1� ~ ÷�1�
TBCK
Time Base 1 Inte��upt
TB11~TB10
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
LVD Interrupt
The Low Voltage Detector Interrupt is contained within the Multi-function Interrupt. A 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.
TM Interrupt
The Compact and Standard Type TMs have two interrupts each, while the Enhanced Type TM has
three interrupts. All of the TM interrupts are contained within the Multi-function Interrupts in these
devices. For each of the Compact and Standard Type TMs there are two interrupt request flags TnPF
and TnAF and two enable bits TnPE and TnAE. For the Enhanced Type TM there are three interrupt
request flags TnPF, TnAF and TnBF and three enable bits TnPE, TnAE and TnBE. 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, A or B match situation happens.
To allow the program to branch to its respective interrupt vector address, the global interrupt enable
bit, EMI, respective TM Interrupt enable bit, and relevant Multi-function Interrupt enable bit, MFnE,
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 Multi-function 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.
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 pins, 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.
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
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, MFnF, 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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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
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
Rev. 1.30
Bit
7
6
5
4
3
2
1
0
Name
-
-
LVDO
LVDEN
-
VLVD2
VLVD1
VLVD0
R/W
-
-
R
R/W
-
R/W
R/W
R/W
POR
-
-
0
0
-
0
0
0
Bit 7~6
unimplemented, read as “0”
Bit 5
LVDO: LVD Output Flag
0: No Low Voltage Detect
1: Low Voltage Detect
Bit 4
LVDON: Low Voltage Detector control
0: disable
1: enable
Bit 3
unimplemented, read as “0”
Bit 2~0
VLVD2~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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Enhanced A/D Flash Type MCU with High Current LED Driver
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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 or IDLE 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
or IDLE Mode.
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Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Configuration Options
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 Options
1
High Speed System Oscillator Selection - fH: HXT, HIRC
2
High Speed Internal RC Frequency Selection - fHIRC: 4MHz, 8MHz or 12MHz
3
fSUB Oscillator Selection – fSUB: LIRC
Watchdog Options
4
Watchdog Timer: always enabled or controlled by software register
Application Circuit
V
D D
V D D
0 .1 F
V S S
A N 0 ~ A N 7
P A 7
O S C
C ir c u it
O S C 1 /P A 6
O S C 2 /P A 5
O S C
C ir c u it
P B 0 ~ P B 2
P C 0 ~ P C 7
P D 0 ~ P D 1
X T 1 /P A 4
X T 2 /P A 3
Rev. 1.30
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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 microcontrollers, 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 three 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 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 Operations
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
where 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 following table depicts a summary of the instruction set categorised according to function and
can be consulted as a basic instruction reference using the following listed conventions.
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 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,[m]
SBCM A,[m]
DAA [m]
Logic Operation
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 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
1Note
1Note
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
C
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
1
1
1
1Note
1Note
1Note
1
1
1
1Note
1
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Arithmetic
Increment & Decrement
INCA [m]
INC [m]
DECA [m]
DEC [m]
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
RRA [m]
RR [m]
RRCA [m]
RRC [m]
RLA [m]
RL [m]
RLCA [m]
RLC [m]
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
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Mnemonic
Description
Cycles
Flag Affected
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
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 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
2
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
Read table (current page) to TBLH and Data Memory
Read table (last page) to TBLH and Data Memory
2Note
2Note
None
None
No operation
Clear Data Memory
Set Data Memory
Clear Watchdog Timer
Pre-clear Watchdog Timer
Pre-clear Watchdog Timer
Swap nibbles of Data Memory
Swap nibbles of Data Memory with result in ACC
Enter power down mode
1
1Note
1Note
1
1
1
1Note
1
1
None
None
None
TO, PDF
TO, PDF
TO, PDF
None
None
TO, PDF
Data Move
MOV A,[m]
MOV [m],A
MOV A,x
Bit Operation
CLR [m].i
SET [m].i
Branch
JMP addr
SZ [m]
SZA [m]
SZ [m].i
SNZ [m].i
SIZ [m]
SDZ [m]
SIZA [m]
SDZA [m]
CALL addr
RET
RET A,x
RETI
Table Read
TABRDC [m]
TABRDL [m]
Miscellaneous
NOP
CLR [m]
SET [m]
CLR WDT
CLR WDT1
CLR WDT2
SWAP [m]
SWAPA [m]
HALT
Note: 1. For skip instructions, if the result of the comparison involves a skip then two 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 WDT1" and "CLR WDT2" instructions the TO and PDF flags may be affected
by the execution status. The TO and PDF flags are cleared after both "CLR WDT1" and "CLR
WDT2" instructions are consecutively executed. Otherwise the TO and PDF flags remain
unchanged.
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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
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
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
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
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
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
CALL addr
Description
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
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Operation
Affected flag(s)
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
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)
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Affected flag(s)
[m].0 ← [m].7
None
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
RRCA [m]
Rotate Data Memory right through Carry with result in ACC
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Description
Operation
Affected flag(s)
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
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
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
SET [m]
Description
Set Data Memory
Each bit of the specified Data Memory is set to 1.
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Operation
Affected flag(s)
[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 bit i of Data Memory is not 0
If bit i 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].i ≠ 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
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
SUB A,x
Description
Subtract immediate data from ACC
The immediate data specified by the code is subtracted from the contents of the Accumulator. Rev. 1.30
167
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Operation
Affected flag(s)
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
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
TABRD [m]
Description
Operation
Affected flag(s)
Read table to TBLH and Data Memory
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
TABRDL [m]
Description
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 Rev. 1.30
168
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Operation
Affected flag(s)
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
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
Affected flag(s)
Z
Rev. 1.30
169
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
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
• PB FREE Products
• Green Packages Products
Rev. 1.30
170
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
16-pin DIP (300mil) Outline Dimensions
Fig1. Full Lead Packages
Fig2. 1/2 Lead Packages
fig 1
Symbol
Dimensions in inch
Min.
Nom.
Max.
A
0.780
0.790
0.800
B
0.240
0.250
0.280
C
0.115
0.130
0.195
D
0.115
0.130
0.150
E
0.014
0.018
0.022
F
0.045
0.060
0.070
G
—
0.1 BSC
—
H
0.300
0.310
0.325
I
—
—
0.430
Symbol
Dimensions in mm
Min.
Nom.
Max.
A
19.81
20.07
20.32
B
6.10
6.35
7.11
C
2.92
3.30
4.95
D
2.92
3.30
3.81
E
0.36
0.46
0.56
1.78
F
1.14
1.52
G
—
2.54 BSC
—
H
7.62
7.87
8.26
I
—
—
10.92
Rev. 1.30
171
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
fig 2
Symbol
Dimensions in inch
Min.
Nom.
Max.
A
0.745
0.765
0.785
B
0.275
0.285
0.295
C
0.120
0.135
0.150
D
0.110
0.130
0.150
E
0.014
0.018
0.022
F
0.045
0.050
0.060
G
—
0.1 BSC
—
H
0.300
0.310
0.325
I
—
—
0.430
Symbol
Dimensions in mm
Min.
Nom.
Max.
19.94
A
18.92
19.43
B
6.99
7.24
7.49
C
3.05
3.43
3.81
D
2.79
3.30
3.81
E
0.36
0.46
0.56
F
1.14
1.27
1.52
G
—
2.54 BSC
—
H
7.62
7.87
8.26
I
—
—
10.92
fig 2
Symbol
Dimensions in inch
Min.
Nom.
Max.
A
0.735
0.755
0.775
B
0.240
0.250
0.280
C
0.115
0.130
0.195
D
0.115
0.130
0.150
E
0.014
0.018
0.022
0.070
F
0.045
0.060
G
—
0.1 BSC
—
H
0.300
0.310
0.325
I
—
—
0.430
Symbol
Dimensions in mm
Min.
Nom.
Max.
19.69
A
18.67
19.18
B
6.10
6.35
7.11
C
2.92
3.30
4.95
D
2.92
3.30
3.81
E
0.36
0.46
0.56
F
1.14
1.52
1.78
G
—
2.54 BSC
—
H
7.62
7.87
8.26
I
—
—
10.92
Rev. 1.30
172
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
16-pin NSOP (150mil) Outline Dimensions
Symbol
Dimensions in inch
Min.
Nom.
Max.
—
A
—
0.236 BSC
B
—
0.154 BSC
—
C
0.012
—
0.020
C'
—
0.390 BSC
—
D
—
—
0.069
E
—
0.050 BSC
—
F
0.004
—
0.010
G
0.016
—
0.050
H
0.004
—
0.010
α
0°
―
8°
Symbol
Rev. 1.30
Dimensions in mm
Min.
Nom.
Max.
A
—
6 BSC
—
B
—
3.9 BSC
—
0.51
C
0.31
—
C'
—
9.9 BSC
—
D
—
—
1.75
E
—
1.27 BSC
—
F
0.10
—
0.25
G
0.40
—
1.27
H
0.10
—
0.25
α
0°
―
8°
173
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
20-pin DIP (300mil) Outline Dimensions
Fig1. Full Lead Packages
Fig2. 1/2 Lead Packages
Fig 1
Symbol
Dimensions in inch
Min.
Nom.
Max.
A
0.980
1.030
1.060
B
0.240
0.250
0.280
C
0.115
0.130
0.195
0.150
D
0.115
0.130
E
0.014
0.018
0.022
F
0.045
0.060
0.070
G
—
0.1 BSC
—
H
0.300
0.310
0.325
I
—
—
0.430
Symbol
Dimensions in mm
Min.
Nom.
Max.
26.92
A
24.89
26.16
B
6.10
6.35
7.11
C
2.92
3.30
4.95
D
2.92
3.30
3.81
E
0.36
0.46
0.56
F
1.14
1.52
1.78
G
—
2.54 BSC
—
H
7.62
7.87
8.26
I
—
—
10.92
Rev. 1.30
174
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Fig 2
Symbol
Dimensions in inch
Min.
Nom.
Max.
A
0.945
0.965
0.985
B
0.275
0.285
0.295
C
0.120
0.135
0.150
D
0.110
0.130
0.150
E
0.014
0.018
0.022
F
0.045
0.050
0.060
G
—
0.1 BSC
—
H
0.300
0.310
0.325
I
—
—
0.430
Symbol
Dimensions in mm
Min.
Nom.
Max.
A
24.00
24.51
25.02
B
6.99
7.24
7.49
C
3.05
3.43
3.81
D
2.79
3.30
3.81
E
0.36
0.46
0.56
F
1.14
1.27
1.52
G
—
2.54 BSC
—
H
7.62
7.87
8.26
I
—
—
10.92
Rev. 1.30
175
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
20-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’
—
0.504 BSC
—
D
—
—
0.104
E
—
0.050 BSC
—
0.012
F
0.004
—
G
0.016
—
0.050
H
0.008
—
0.013
α
0°
—
8°
Symbol
Dimensions in mm
Min.
Nom.
Max.
A
—
10.30 BSC
—
B
—
7.5 BSC
—
0.51
C
0.31
—
C’
—
12.8 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°
Rev. 1.30
176
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
24-pin SKDIP (300mil) Outline Dimensions
Fig1. Full Lead Packages
Fig2. 1/2 Lead Packages
see fig1
A
Min.
1.230
Dimensions in inch
Nom.
1.250
Max.
1.280
Symbol
B
0.240
0.250
0.280
C
0.115
0.130
0.195
D
0.115
0.130
0.150
E
0.014
0.018
0.022
F
0.045
0.060
0.070
G
—
0.1 BSC
—
H
0.300
0.310
0.325
I
—
—
0.430
A
Min.
31.24
Dimensions in mm
Nom.
31.75
Max.
32.51
B
6.10
6.35
7.11
C
2.92
3.30
4.95
D
2.92
3.30
3.81
E
0.36
0.46
0.56
Symbol
Rev. 1.30
F
1.14
1.52
1.78
G
—
2.54 BSC
—
H
7.62
7.87
8.26
I
—
—
10.92
177
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
see fig2
A
Min.
1.160
Dimensions in inch
Nom.
1.185
Max.
1.195
Symbol
B
0.240
0.250
0.280
C
0.115
0.130
0.195
D
0.115
0.130
0.150
E
0.014
0.018
0.022
F
0.045
0.060
0.070
G
—
0.1 BSC
—
H
0.300
0.310
0.325
I
—
—
0.430
Symbol
Dimensions in mm
Min.
Nom.
Max.
30.35
A
29.46
30.10
B
6.10
6.35
7.11
C
2.92
3.30
4.95
D
2.92
3.30
3.81
E
0.36
0.46
0.56
F
1.14
1.52
1.78
G
—
2.54 BSC
—
H
7.62
7.87
8.26
I
—
—
10.92
A
Min.
1.145
Dimensions in inch
Nom.
1.165
Max.
1.185
see fig20
Symbol
B
0.275
0.285
0.295
C
0.120
0.135
0.150
D
0.110
0.130
0.150
E
0.014
0.018
0.022
0.060
F
0.045
0.050
G
—
0.1 BSC
—
H
0.300
0.310
0.325
I
—
—
0.430
A
Min.
29.08
Dimensions in mm
Nom.
29.59
Max.
30.10
Symbol
Rev. 1.30
B
6.99
7.24
7.49
C
3.05
3.43
3.81
D
2.79
3.30
3.81
E
0.36
0.46
0.56
1.52
F
1.14
1.27
G
—
2.54 BSC
—
H
7.62
7.87
8.26
I
—
—
10.92
178
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
24-pin SOP (300mil) Outline Dimensions
Symbol
A
Dimensions in inch
Min.
Nom.
Max.
—
0.406 BSC
—
B
—
0.295 BSC
—
C
0.012
—
0.020
C’
—
0.606 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. 1.30
Dimensions in mm
Min.
Nom.
A
—
10.30 BSC
Max.
—
B
—
7.5 BSC
—
C
0.31
—
0.51
C’
—
15.4 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°
179
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
28-pin SKDIP (300mil) Outline Dimensions
Symbol
Dimensions in inch
Min.
Nom.
Max.
A
1.380
—
1.420
B
0.280
—
0.310
C
0.060
—
0.130
D
0.125
—
0.200
E
0.015
—
0.022
F
0.045
—
0.065
G
—
0.1 BSC
—
H
0.300
—
0.325
I
—
—
0.400
Symbol
Rev. 1.30
Dimensions in mm
Min.
Nom.
Max.
A
35.05
—
36.07
B
7.11
—
7.87
C
1.52
—
3.30
D
3.18
—
5.08
E
0.38
—
0.56
F
1.14
—
1.65
G
—
2.54 BSC
—
H
7.62
—
8.26
I
—
—
10.16
180
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
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. 1.30
Dimensions in mm
Min.
Nom.
Max.
A
—
10.30 BSC
—
B
—
7.5 BSC
—
C
0.31
—
0.51
C’
—
17.9 BSC
—
2.65
D
—
—
E
—
1.27 BSC
—
F
0.10
—
0.30
G
0.40
—
1.27
H
0.20
—
0.33
α
0°
―
8°
181
March 13, 2015
Enhanced A/D Flash Type MCU with High Current LED Driver
HT66F24D/HT66F25D/HT66F26D
Copyright© 2013 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. 1.30
182
March 13, 2015