HOLTEK HT48R005

Small Package 8-Bit OTP MCU
HT48R005/HT46R005
Revision: 1.00
November 29, 2011
HT48R005/HT46R005
Table of Contents
Features ...............................................................................................5
CPU Features ........................................................................................................5
Peripheral Features ................................................................................................5
General Description ............................................................................5
Selection Table ....................................................................................6
Block Diagram .....................................................................................6
Pin Assignment ...................................................................................6
Pin Description ....................................................................................7
HT48R005..............................................................................................................7
HT46R005..............................................................................................................8
Absolute Maximum Ratings ...............................................................8
D.C. Characteristics ............................................................................9
A.C. Characteristics ..........................................................................10
ADC Characteristics..........................................................................11
Power-on Reset Characteristics ......................................................11
System Architecture .........................................................................12
Clocking and Pipelining ........................................................................................12
Program Counter..................................................................................................13
Stack ....................................................................................................................13
Arithmetic and Logic Unit - ALU ...........................................................................13
Program Memory...............................................................................14
Structure...............................................................................................................14
Special Vectors.....................................................................................................14
Look-up Table.......................................................................................................14
Table Program Example .......................................................................................15
Data Memory......................................................................................16
Structure...............................................................................................................16
Special Purpose Data Memory .............................................................................16
Special Function Registers ..............................................................17
Indirect Addressing Registers - IAR0, IAR1 .........................................................17
Memory Pointers - MP0, MP1..............................................................................17
Accumulator - ACC .............................................................................................17
Program Counter Low Register - PCL..................................................................18
Status Register - STATUS ...................................................................................18
Input/Output Ports and Control Registers .............................................................18
Rev. 1.00
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November 29, 2011
HT48R005/HT46R005
System Control Registers - CTRL0, CTRL1.........................................................19
Wake-up Function Register - PAWK ....................................................................19
Pull-high Registers - PAPU ..................................................................................19
Oscillator............................................................................................20
System Oscillator Overview..................................................................................20
System Clock Configurations................................................................................20
External Crystal/Resonator Oscillator - HXT ........................................................20
External RC Oscillator - ERC ...............................................................................20
Internal RC Oscillator - HIRC ...............................................................................21
Internal Low Speed Oscillator - LIRC ...................................................................21
Operating Modes ...............................................................................21
Mode Switching ....................................................................................................21
Standby Current Considerations...........................................................................21
Wake-up...............................................................................................................22
Watchdog Timer ................................................................................23
Watchdog Timer Operation...................................................................................23
Reset and Initialisation .....................................................................24
Reset Functions ...................................................................................................24
Reset Initial Conditions .........................................................................................25
HT48R005............................................................................................................26
HT46R005............................................................................................................27
Input/Output Ports.............................................................................28
Pull-high Resistors................................................................................................28
Port A Wake-up ....................................................................................................28
I/O Port Control Registers.....................................................................................29
Pin-shared Functions............................................................................................29
I/O Pin Structures .................................................................................................29
Programming Considerations ...............................................................................29
Timer/Event Counters .......................................................................31
Configuring the Timer/Event Counter Input Clock Source .....................................31
Timer Registers - TMR.........................................................................................31
Timer Control Registers - TMR0C........................................................................31
Timer Mode ..........................................................................................................33
Event Counter Mode.............................................................................................33
Pulse Width Capture Mode...................................................................................33
Prescaler ..............................................................................................................34
PFD Function .......................................................................................................34
I/O Interfacing.......................................................................................................35
Programming Considerations ...............................................................................35
Timer Program Example.......................................................................................36
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HT48R005/HT46R005
Analog to Digital Converter..............................................................37
A/D Overview .......................................................................................................37
A/D Converter Register Description ......................................................................37
A/D Converter Data Registers - ADRL, ADRH .....................................................37
A/D Converter Control Registers - ADCR, ACSR.................................................38
A/D Operation.......................................................................................................39
A/D Input Pins ......................................................................................................40
Summary of A/D Conversion Steps ......................................................................40
Programming Considerations ...............................................................................40
A/D Transfer Function...........................................................................................41
A/D Programming Example ..................................................................................41
Interrupts............................................................................................43
Interrupt Register..................................................................................................43
Interrupt Operation ...............................................................................................43
Interrupt Priority.....................................................................................................44
External Interrupt ..................................................................................................44
Timer/Event Counter Interrupt ..............................................................................46
Programming Considerations ...............................................................................46
Configuration Options ......................................................................46
Application Circuits ..........................................................................47
Instruction Set ...................................................................................48
Introduction ..........................................................................................................48
Instruction Timing .................................................................................................48
Moving and Transferring Data ..............................................................................48
Arithmetic Operations ...........................................................................................48
Logical and Rotate Operations .............................................................................48
Branches and Control Transfer.............................................................................48
Table Read Operations.........................................................................................49
Instruction Set Summary ......................................................................................49
Instruction Definition ........................................................................51
Package Information .........................................................................61
10-pin MSOP Outline Dimensions ........................................................................61
Rev. 1.00
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HT48R005/HT46R005
Features
· All instructions executed in one or two instruction
CPU Features
cycles
· Operating voltage:
· Table read instructions
fSYS= 12MHz: 2.2V~5.5V
fSYS= 16MHz: 3.0V~5.5V
· 63 powerful instructions
· Up to 0.33ms instruction cycle with 12MHz system
· 2-level subroutine nesting
clock at VDD= 5V
· Bit manipulation instruction
· Sleep mode and wake-up functions to reduce
· Low voltage reset function
power consumption
· Wide range of available package types
· Oscillator types:
External high freuency Crystal -- HXT
External RC -- ERC
Internal RC -- HIRC
Peripheral Features
· 6 bidirectional I/O lines
· 3 channel 12-bit ADC
· Two operational modes: Normal, Sleep
· External interrupt input shared with an I/O line
· Fully integrated internal 4MHz, 8MHz and 12MHz
· Single 8-bit programmable Timer/Event
oscillator requires no external components
Counter with overflow interrupt and prescaler
· OTP Program Memory: 0.5K´14
· Buzzer driving pair supported
· RAM Data Memory: 32´8
· Package types: 10-pin MSOP
· Watchdog Timer function
· LIRC oscillator function for watchdog timer
General Description
The HT46R005 and HT48R005 are a series of 8-bit high
performance, RISC architecture microcontrollers specifically designed for a wide range of applications. The
usual Holtek microcontroller features of low power consumption, I/O flexibility, timer functions, oscillator options, power down and wake-up functions, watchdog
timer and low voltage reset, combine to provide devices
with a huge range of functional options while still main-
Rev. 1.00
taining a high level of cost effectiveness. The fully integrated system oscillator HIRC, which requires no
external components and which has three frequency
selections, opens up a huge range of new application
possibilities for these devices, some of which may include industrial control, consumer products, household
appliances subsystem controllers, etc.
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November 29, 2011
HT48R005/HT46R005
Selection Table
Program
Memory
Data
Memory
I/O
HT48R005
0.5K´14
32´8
HT46R005
0.5K´14
32´8
Part No.
Note:
Interrupt
8-bit
Timer
Time
Base
Ext.
Int.
6
1
1
1
6
1
1
1
A/D
Buzzer
Stack
Package
1
¾
2
12-bit´3
1
2
10MSOP
1
2
10MSOP
The internal clock in the table is a fully integrated RC oscillator requiring no external components which can be
used as the system clock.
Block Diagram
The following block diagram illustrates the main functional blocks.
T im in g
G e r n e r a tio n
B u z z e r
D r iv e r
I/O
P o rts
8 - b it
R IS C
M C U
C o re
A /D
C o n v e rte r
R O M /R A M
M e m o ry
T im e r
Pin Assignment
V D D
1
1 0
V D D
1
1 0
P A 6 /O S C 1
2
9
P A 0 /B Z
P A 6 /O S C 1
2
9
P A 0 /B Z /A N 0
P A 5 /O S C 2
3
8
P A 1 /B Z
P A 5 /O S C 2
3
8
P A 1 /B Z /A N 1
P A 7 /R E S
4
7
P A 2 /T M R /IN T
P A 7 /R E S
4
7
P A 2 /T M R /IN T /A N 2
N C
5
6
N C
N C
5
6
N C
V S S
H T 4 8 R 0 0 5
1 0 M S O P -A
Rev. 1.00
V S S
H T 4 6 R 0 0 5
1 0 M S O P -A
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November 29, 2011
HT48R005/HT46R005
Pin Description
HT48R005
Pin Name
Function
OPT
I/T
PA0
PAPU
PAWK
ST
CMOS General purpose I/O. Register enabled pull-up and wake-up.
BZ
CTRL0
¾
CMOS Buzzer output pin
PA1
PAPU
PAWK
ST
CMOS General purpose I/O. Register enabled pull-up and wake-up.
BZ
CTRL0
¾
PA2
PAPU
PAWK
ST
TMR
¾
ST
¾
External Timer clock input
INT
¾
ST
¾
External interrupt input
PA5
PAPU
PAWK
ST
OSC2
CO
¾
PA6
PAPU
PAWK
ST
OSC1
CO
OSC
PA7
PAWK
ST
RES
CO
ST
¾
Reset input
VDD
VDD
¾
PWR
¾
Power supply
VSS
VSS
¾
PWR
¾
Ground
PA0/BZ
PA1/BZ
PA2/TMR/INT
PA5/OSC2
PA6/OSC1
PA7/RES
Note:
O/T
Description
¾
Buzzer complementary output pin
CMOS General purpose I/O. Register enabled pull-up and wake-up.
CMOS General purpose I/O. Register enabled pull-up and wake-up.
OSC
Oscillator pin
CMOS General purpose I/O. Register enabled pull-up and wake-up.
¾
Oscillator pin
NMOS General purpose I/O. Register enabled wake-up.
I/T: Input type
O/T: Output type
OPT: Optional by configuration option (CO) or register option
PWR: Power
CO: Configuration option
ST: Schmitt Trigger input
CMOS: CMOS output
Rev. 1.00
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November 29, 2011
HT48R005/HT46R005
HT46R005
Pin Name
Function
OPT
I/T
PA0
PAPU
PAWK
ST
CMOS General purpose I/O. Register enabled pull-up and wake-up.
BZ
CTRL0
¾
CMOS Buzzer output pin
AN0
ADCR
AN
PA1
PAPU
PAWK
ST
BZ
CTRL0
¾
¾
Buzzer complementary output pin
AN1
ADCR
AN
¾
A/D channel 1
PA2
PAPU
PAWK
ST
TMR
¾
ST
¾
External Timer clock input
INT
¾
ST
¾
External interrupt input
AN2
ADCR
AN
¾
A/D channel 2
PA5
PAPU
PAWK
ST
OSC2
CO
¾
PA6
PAPU
PAWK
ST
OSC1
CO
OSC
PA7
PAWK
ST
RES
CO
ST
¾
Reset input
VDD
VDD
¾
PWR
¾
Power supply
VSS
VSS
¾
PWR
¾
Ground
PA0/BZ/AN0
PA1/BZ/AN1
PA2/TMR/INT/AN2
PA5/OSC2
PA6/OSC1
PA7/RES
Note:
O/T
Description
¾
A/D channel 0
CMOS General purpose I/O. Register enabled pull-up and wake-up.
CMOS General purpose I/O. Register enabled pull-up and wake-up.
CMOS General purpose I/O. Register enabled pull-up and wake-up.
OSC
Oscillator pin
CMOS General purpose I/O. Register enabled pull-up and wake-up.
¾
Oscillator pin
NMOS General purpose I/O. Register enabled wake-up.
I/T: Input type
O/T: Output type
OPT: Optional by configuration option (CO) or register option
PWR: Power
CO: Configuration option
ST: Schmitt Trigger input
CMOS: CMOS output
AN: Analog input pin
Absolute Maximum Ratings
Supply Voltage ...........................VSS-0.3V to VSS+6.0V
Storage Temperature ............................-50°C to 125°C
Input Voltage..............................VSS-0.3V to VDD+0.3V
IOL Total ..............................................................100mA
Total Power Dissipation .....................................500mW
Operating Temperature...........................-40°C to 85°C
IOH Total............................................................-100mA
Note: These are stress ratings only. Stresses exceeding the range specified under ²Absolute Maximum Ratings² 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.
Rev. 1.00
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November 29, 2011
HT48R005/HT46R005
D.C. Characteristics
Ta=25°C
Test Conditions
Symbol
Parameter
Min.
Typ.
Max.
Unit
fSYS=12MHz
2.2
¾
5.5
V
fSYS=16MHz
3.0
¾
5.5
V
¾
¾
1
mA
¾
¾
3
mA
¾
¾
2
mA
¾
¾
4
mA
¾
¾
7
mA
¾
¾
3
mA
¾
¾
10
mA
¾
¾
1
mA
¾
¾
2
mA
0
¾
1.5
V
0
¾
0.2VDD
3.5
¾
5.0
0.8VDD
¾
VDD
VDD
VDD
IDD1
IDD2
Operating Voltage
Operating Current
(Crystal/RC OSC)
Operating Current
(Crystal/RC OSC)
IDD3
Operating Current
(Crystal/RC OSC)
ISTB1
Standby Current
(WDTOSC on)
ISTB2
Standby Current
(WDTOSC on)
¾
3V
5V
3V
5V
5V
Conditions
No load, fSYS=4MHz
A/D disabled
No load, fSYS=8MHz
A/D disabled
No load, fSYS=16MHz
A/D disabled
3V
No load, system HALT
5V
3V
No load, system HALT
5V
¾
Input Low Voltage for I/O,
TMR and INT
5V
VIH1
Input High Voltage for I/O,
TCn and INT
5V
VIL2
Input Low Voltage (RES)
¾
¾
0
¾
0.4VDD
V
VIH2
Input High Voltage (RES)
¾
¾
0.9VDD
¾
VDD
V
VLVR1
Low Voltage Reset 1
¾
VLVR = 2.10V
1.98
2.10
2.22
V
VLVR2
Low Voltage Reset 2
¾
VLVR = 3.15V
2.98
3.15
3.32
V
VLVR3
Low Voltage Reset 3
¾
VLVR = 4.20V
3.98
4.20
4.42
V
IOH
-2
-4
¾
mA
I/O Port Source Current
-5
-10
¾
mA
4
8
¾
mA
10
20
¾
mA
2
3
¾
mA
VIL1
¾
¾
¾
3V
VOH=0.9VDD
5V
IOL1
3V
I/O Port Sink Current
VOL=0.1VDD
5V
IOL2
PA7 Sink Current
RPH
Pull-high Resistance
5V
VOL=0.1VDD
V
3V
¾
20
60
100
kW
5V
¾
10
30
50
kW
Note: The standby current ISTB1 and ISTB2 are measured with all I/O pins in input mode and tied to VDD.
Rev. 1.00
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November 29, 2011
HT48R005/HT46R005
A.C. Characteristics
Symbol
fSYS
Parameter
System Clock
Ta=25°C
Test Conditions
Min.
Typ.
Max.
Unit
2.2V~5.5V
400
¾
12000
kHz
3.0V~5.5V
400
¾
16000
kHz
3V/5V Ta=25°C
-2%
4
+2%
MHz
3V/5V Ta=25°C
-2%
8
+2%
MHz
-2%
12
+2%
MHz
3V/5V Ta=0~70°C
-5%
4
+5%
MHz
3V/5V Ta=0~70°C
-5%
8
+5%
MHz
+5%
MHz
VDD
¾
5V
fHIRC
System Clock
(ERC)
fERC
Timer Input Frequency
(TMR)
fTIMER
Ta=25°C
Ta=0~70°C
-5%
12
2.2V~
Ta=0~70°C
3.6V
-8%
4
+8%
MHz
3.0V~
Ta=0~70°C
5.5V
-8%
4
+8%
MHz
3.0V~
Ta=0~70°C
5.5V
-8%
8
+8%
MHz
4.5V~
Ta=0~70°C
5.5V
-8%
12
+8%
MHz
2.2V~
Ta= -40°C~85°C
3.6V
-12%
4
+12%
MHz
3.0V~
Ta= -40°C~85°C
5.5V
-12%
4
+12%
MHz
3.0V~
Ta= -40°C~85°C
5.5V
-12%
8
+12%
MHz
4.5V~
Ta= -40°C~85°C
5.5V
-12%
12
+12%
MHz
5V
System Clock
(HIRC)
Conditions
5V
Ta=25°C, R=120kW *
-2%
4
+2%
MHz
5V
Ta=0~70°C, R=120kW *
-5%
4
+5%
MHz
5V
Ta= -40°C~85°C,
R=120kW *
-7%
4
+7%
MHz
2.2V~ Ta= -40°C~85°C,
5.5V R=120kW *
-11%
4
+11%
MHz
2.2V~5.5V
0
¾
4000
kHz
3.3V~5.5V
0
¾
8000
kHz
4.5V~5.5V
0
¾
12000
kHz
¾
3V
¾
5
10
15
kHz
5V
¾
6.5
13.0
19.5
kHz
External Reset Low Pulse Width
¾
¾
1
¾
¾
ms
tSYS
fLIRC
LIRC Oscillator
tRES
tSST
System Start-up time Period
¾
Wake up from HALT mode
2
128
¾
tINT
Interrupt Pulse Width
¾
¾
1
¾
¾
ms
tLVR
Low Voltage Width to Reset
¾
¾
0.25
1
2
ms
tRSTD
Reset Delay Time
¾
¾
¾
100
¾
ms
Note:
1. tSYS=1/fSYS
2. *For fERC, as the resistor tolerance will influence the frequency a precision resistor is recommended.
Rev. 1.00
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November 29, 2011
HT48R005/HT46R005
ADC Characteristics
Ta=25°C
Test Conditions
Symbol
Parameter
Min.
Typ.
Max.
Unit
tAD=0.5ms
-2
¾
2
LSB
tAD=0.5ms
-4
¾
4
LSB
¾
0.5
0.75
mA
¾
1.0
1.5
mA
VDD
3V
DNL
ADC Differential Non-Linearity
5V
3V
INL
ADC Integral Non-Linearity
5V
IADC
Additional Power Consumption
if A/D Converter is Used
Conditions
3V
¾
5V
Power-on Reset Characteristics
Ta=25°C
Test Conditions
Symbol
Parameter
VDD
Conditions
Min.
Typ.
Max.
Unit
VPOR
VDD Start Voltage to Ensure
Power-on Reset
¾
¾
¾
¾
100
mV
RRVDD
VDD raising rate to Ensure
Power-on Reset
¾
¾
0.035
¾
¾
V/ms
tPOR
Minimum Time for VDD Stays at
VPOR to Ensure Power-on Reset
¾
¾
1
¾
¾
ms
V
D D
tP
O R
R R
V D D
V
P O R
T im e
Rev. 1.00
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November 29, 2011
HT48R005/HT46R005
System Architecture
A key factor in the high-performance features of the
Holtek range of microcontrollers is attributed to the 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 operations of the instruction set. It 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.
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.
For instructions involving branches, such as jump or call
instructions, two instruction 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.
Clocking and Pipelining
The main system clock, derived from either a Crystal/Resonator or RC oscillator is subdivided into four internally generated non-overlapping clocks, T1~T4. The
O s c illa to r C lo c k
( S y s te m C lo c k )
P h a s e C lo c k T 1
P h a s e C lo c k T 2
P h a s e C lo c k T 3
P h a s e C lo c k T 4
P ro g ra m
C o u n te r
P ip e lin in g
P C
P C + 1
F e tc h In s t. (P C )
E x e c u te In s t. (P C -1 )
P C + 2
F e tc h In s t. (P C + 1 )
E x e c u te In s t. (P C )
F e tc h In s t. (P C + 2 )
E x e c u te In s t. (P C + 1 )
System Clocking and Pipelining
3
M O V A ,[1 2 H ]
C A L L D E L A Y
C P L [1 2 H ]
5
:
1
2
F e tc h In s t. 1
E x e c u te In s t. 1
F e tc h In s t. 2
F e tc h In s t. 3
:
4
E x e c u te In s t. 2
F e tc h In s t. 6
N O P
6
F lu s h P ip e lin e
E x e c u te In s t. 6
F e tc h In s t. 7
D E L A Y :
Instruction Fetching
Rev. 1.00
12
November 29, 2011
HT48R005/HT46R005
Program Counter
space, and is neither readable nor writeable. The activated level is indexed by the Stack Pointer, SP, 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.
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 ²JMP² or ²CALL² that demand a jump to a
non-consecutive Program Memory address. Note that
the Program Counter width varies with the Program
Memory capacity depending upon which device is selected. However, it must be noted that only the lower 8
bits, known as the Program Counter Low Register, are
directly addressable by user.
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.
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.
P ro g ra m
Program Counter
Device
HT48R005
HT46R005
Program Counter
High Byte
PCL Register
PC9~PC8
PCL7~PCL0
S ta c k
P o in te r
T o p o f
S ta c k
B o tto m
o f S ta c k
S ta c k L e v e l 1
S ta c k L e v e l 2
C o u n te r
P ro g ra m
M e m o ry
Arithmetic and Logic Unit - ALU
The arithmetic-logic unit or ALU is a critical area of the
microcontroller that carries out arithmetic and logic operations of the instruction set. Connected to the main
microcontroller data bus, the ALU receives related instruction codes and performs the required arithmetic or
logical operations after which the result will be placed in
the specified register. As these ALU calculation or operations may result in carry, borrow or other status
changes, the status register will be correspondingly updated to reflect these changes. The ALU supports the
following functions:
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.
The lower byte of the Program Counter is fully accessible under program control. Manipulating the PCL might
cause program branching, so an extra cycle is needed
to pre-fetch. Further information on the PCL register can
be found in the Special Function Register section.
· Arithmetic operations: ADD, ADDM, ADC, ADCM,
Stack
· Increment and Decrement INCA, INC, DECA, DEC
This is a special part of the memory which is used to
save the contents of the Program Counter only. The
stack is neither part of the Data or Program Memory
· Branch decision, JMP, SZ, SZA, SNZ, SIZ, SDZ,
SUB, SUBM, SBC, SBCM, DAA
· Logic operations: AND, OR, XOR, ANDM, ORM,
XORM, CPL, CPLA
· Rotation RRA, RR, RRCA, RRC, RLA, RL, RLCA,
RLC
Rev. 1.00
SIZA, SDZA, CALL, RET, RETI
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HT48R005/HT46R005
Program Memory
· Timer/Event counter interrupt vector
The Program Memory is the location where the user
code or program is stored. The device is supplied with
One-Time Programmable, OTP, memory where users
can program their application code into the device. By
using the appropriate programming tools, OTP devices
offer users the flexibility to freely develop their applications which may be useful during debug or for products
requiring frequent upgrades or program changes.
This internal vector is used by the Timer/Event Counters. If a Timer/Event Counter overflow occurs, the
program will jump to its respective location and begin
execution if the associated Timer/Event Counter interrupt is enabled and the stack is not full.
· A/D interrupt vector
This internal vector is used by the A/D converter. If
A/D conversion complete , the program will jump to
this location and begin execution if the A/D interrupt is
enabled and the stack is not full.
Structure
The Program Memory has a capacity of 0.5K´14 to
2K´15. 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 separate table pointer registers.
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 lower order address of the
look up data to be retrieved in the table pointer register,
TBLP. This register defines the lower 8-bit address of
the look-up table.
Special Vectors
Within the Program Memory, certain locations are reserved for special usage such as reset and interrupts.
After setting up the table pointer, the table data can be
retrieved from the current Program Memory page or last
Program Memory page using the ²TABRDC[m]² or
²TABRDL [m]² instructions, respectively. When these instructions are 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 ²0².
· Reset Vector
This vector 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.
· External interrupt vector
This vector is used by the external interrupt. If the external interrupt pin on the device receives an edge
transition, the program will jump to this location and
begin execution if the external interrupt is enabled and
the stack is not full. The external interrupt active edge
transition type, whether high to low, low to high or both
is specified in the CTRL1 register.
H T 4 8 R 0 0 5
H T 4 6 R 0 0 5
0 0 H
R e s e t
0 0 H
R e s e t
0 4 H
E x te rn a l
In te rru p t
0 4 H
E x te rn a l
In te rru p t
0 8 H
T im e r
In te rru p t
0 8 H
T im e r
In te rru p t
0 C H
0 C H
A /D
In te rru p t
1 0 H
1 0 H
1 4 H
1 4 H
1 8 H
1 8 H
1 F F H
1 4 b its
1 F F H
1 4 b its
Program Memory Structure
Rev. 1.00
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November 29, 2011
HT48R005/HT46R005
dress ²106H² 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
²TABRDC [m]² 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 ²TABRDL [m]² instruction is executed.
The following diagram illustrates the addressing/data
flow of the look-up table:
L a s t p a g e o r
p re s e n t p a g e
P C x ~ P C 8
P ro g ra m
H ig h B y te
A d d re s s
P C
T B L P R e g is te r
M e m o ry
D a ta
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 the table read instructions. If using the table
read instructions, the Interrupt Service Routines may
change the value of 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.
U s e r S e le c te d
R e g is te r
R e g is te r T B L H
H ig h B y te
L o w
B y te
Table Program Example
The accompanying example shows how the table
pointer and table data is defined and retrieved from the
device. This example uses raw table data located in the
last page which is stored there using the ORG statement. The table pointer is setup here to have an initial
value of ²06H². This will ensure that the first data read
from the data table will be at the Program Memory ad-
Instruction
Table Location Bits
b9
b8
b7
b6
b5
b4
b3
b2
b1
b0
TABRDC [m]
PC9
PC8
@7
@6
@5
@4
@3
@2
@1
@0
TABRDL [m]
1
1
@7
@6
@5
@4
@3
@2
@1
@0
Table Location
Note:
PC9~PC8: Current program Counter bits
@7~@0: Table Pointer TBLP bits
· Table Read Program Example - 0.5K ROM size
tempreg1 db ?
; temporary register #1
tempreg2 db ?
; temporary register #2
:
:
mov a,06h
; initialise table pointer - note that this address is referenced
mov tblp,a
:
:
; to the last page or present page
tabrdl
; transfers value in table referenced by table pointer to tempregl
; data at prog. memory address ²106H² transferred to tempreg1 and TBLH
tempreg1
dec tblp
tabrdl
:
:
org 100h
dc
; reduce value of table pointer by one
tempreg2
;
;
;
;
;
transfers value in table referenced by table pointer to tempreg2
data at prog.memory address ²105H² transferred to tempreg2 and TBLH
in this example the data ²1AH² is transferred to
tempreg1 and data ²0FH² to register tempreg2
the value ²00H² will be transferred to the high byte register TBLH
; sets initial address of last page
00Ah, 00Bh, 00Ch, 00Dh, 00Eh, 00Fh, 01Ah, 01Bh
:
:
Rev. 1.00
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HT48R005/HT46R005
Data Memory
Special Purpose 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.
This area of Data Memory is where registers, necessary
for the correct operation of the microcontroller, are
stored. Most of the registers are both readable and
writeable but some are protected and are readable only,
the details of which are located under the relevant Special Function Register section. Note that for locations
that are unused, any read instruction to these addresses
will return the value ²00H².
Structure
Divided into two sections, the first of these is an area of
RAM where special function registers are located. These
registers have fixed locations and are necessary for correct operation of the device. Many of these registers can
be read from and written to directly under program control, however, some remain protected from user manipulation. The second area of Data Memory is reserved for
general purpose use. All locations within this area are
read and write accessible under program control.
0 0 H
0 1 H
0 2 H
0 3 H
0 4 H
0 5 H
0 6 H
0 7 H
0 8 H
0 9 H
0 A H
0 B H
0 C H
0 D H
0 E H
0 F H
1 0 H
1 1 H
1 2 H
1 3 H
1 4 H
1 5 H
1 6 H
1 7 H
1 8 H
1 9 H
1 A H
1 B H
1 C H
1 D H
1 E H
1 F H
2 0 H
2 1 H
2 2 H
2 3 H
2 4 H
2 5 H
The two sections of Data Memory, the Special Purpose
and General Purpose Data Memory are located at consecutive locations. All are implemented in RAM and are 8
bits wide but the length of each memory section is dictated by the type of microcontroller chosen. The start address of the Data Memory for all devices is the address
²00H².
All microcontroller programs require an area of
read/write memory where temporary data can be stored
and retrieved for use later. It is this area of RAM memory
that is known as General Purpose Data Memory. This
area of Data Memory is fully accessible by the user program for both read and write operations. By using the
²SET [m].i² and ²CLR [m].i² instructions individual bits
can be set or reset under program control giving the
user a large range of flexibility for bit manipulation in the
Data Memory.
0 0 H
IA R 0
0 1 H
M P 0
S p e c ia l
P u rp o s e
R e g is te r s
3 F H
4 0 H
3 2 b y te s
G e n e ra l
P u rp o s e
R e g is te r s
H T 4
IA
M
IA
M
8 R
R
P
R
P
0 0 5
0
0
1
1
H T 4 6
IA
M
IA
M
R 0 0 5
R 0
P 0
R 1
P 1
A C C
P C L
T B L P
T B L H
W D T S
S T A T U S
IN T C 0
T M R 0
T M R 0 C
A C C
P C L
T B L P
T B L H
W D T S
S T A T U S
IN T C 0
T M R 0
T M R 0 C
P A
P A C
P A P U
P A W K
P A
P A C
P A P U
P A W K
C T R L 0
C T R L 1
C T R L 0
C T R L 1
A D
A D
A D
A C
R L
R H
C R
S R
5 F H
Data Memory Structure
Note:
Most of the Data Memory bits can be directly
manipulated using the ²SET [m].i² and ²CLR
[m].i² with the exception of a few dedicated bits.
The Data Memory can also be accessed
through the memory pointer registers.
Rev. 1.00
5 F H
: U n u s e d , re a d a s "0 0 "
Special Purpose Data Memory
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Special Function Registers
Memory Pointers - MP0, MP1
To ensure successful operation of the microcontroller,
certain internal registers are implemented in the Data
Memory area. These registers ensure correct operation
of internal functions such as timers, interrupts, etc., as
well as external functions such as I/O data control. The
location of these registers within the Data Memory begins at the address ²00H². Any unused Data Memory locations between these special function registers and the
point where the General Purpose Memory begins is reserved and attempting to read data from these locations
will return a value of ²00H².
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 indirectly 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. The following example shows how to clear a section of four Data Memory
locations already defined as locations adres1 to adres4.
Indirect Addressing Registers - IAR0, IAR1
Accumulator - ACC
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 Pointer, MP0 or MP1. Acting as a
pair, IAR0 with MP0 and IAR1 with MP1 can together access data from the Data Memory. As the Indirect Addressing Registers are not physically implemented,
reading the Indirect Addressing Registers indirectly will
return a result of ²00H² and writing to the registers indirectly will result in no operation.
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.
· Indirect Addressing Program Example
data .section ¢data¢
adres1 db ?
adres2 db ?
adres3 db ?
adres4 db ?
block db ?
code .section at 0 code
org 00h
start:
mov
mov
mov
mov
a,04h
block,a
a,offset adres1
mp0,a
; setup size of block
loop:
clr
inc
sdz
jmp
IAR0
mp0
block
loop
; clear the data at address defined by MP0
; increment memory pointer
; check if last memory location has been cleared
; Accumulator loaded with first RAM address
; setup memory pointer with first RAM address
continue:
The important point to note here is that in the example shown above, no reference is made to specific Data Memory
addresses.
Rev. 1.00
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HT48R005/HT46R005
Program Counter Low Register - PCL
flag can be affected only by a system power-up, a WDT
time-out or by executing the ²CLR WDT² or ²HALT² instruction. The PDF flag is affected only by executing the
²HALT² or ²CLR WDT² instruction or during a system
power-up.
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.
The Z, OV, AC and C flags generally reflect the status of
the latest operations.
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 interrupt routine can change the status register, precautions must be
taken to correctly save it. Note that bits 0~3 of the
STATUS register are both readable and writeable bits.
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.
Input/Output Ports and Control Registers
Within the area of Special Function Registers, the port
PA data I/O register and its associated control register
PAC plays a prominent role. This register is mapped to
specific address within the Data Memory as shown in
the Data Memory table. The data I/O registers, are used
to transfer the appropriate output or input data on the
port. The control registers specifies which pins of the
port are set as inputs and which are set as outputs. To
setup a pin as an input, the corresponding bit of the control register must be set high, for an output it must be set
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
· STATUS Register
Bit
7
6
5
4
3
2
1
0
Name
¾
¾
TO
PDF
OV
Z
AC
C
R/W
¾
¾
R
R
R/W
R/W
R/W
R/W
POR
¾
¾
0
0
x
x
x
x
²x² unknown
Bit 7, 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Rev. 1.00
Unimplemented, read as ²0²
TO: Watchdog Time-Out flag
0: After power up or executing the ²CLR WDT² or ²HALT² instruction
1: A watchdog time-out occurred.
PDF: Power down flag
0: After power up or executing the ²CLR WDT² instruction
1: By executing the ²HALT² instruction
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.
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
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
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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HT48R005/HT46R005
Wake-up Function Register - PAWK
low. During program initialisation, it is important to first
setup the control registers to specify which pins are outputs and which are inputs before reading data from or
writing data to the I/O ports. One flexible feature of these
registers is the ability to directly program single bits using the ²SET [m].i² and ²CLR [m].i² instructions. The
ability to change I/O pins from output to input and vice
versa by manipulating specific bits of the I/O control registers during normal program operation is a useful feature of these devices.
When the microcontroller enters the Sleep Mode, various methods exist to wake the device up and continue
with normal operation. One method is to allow a falling
edge on the I/O pins to have a wake-up function. This
register is used to select which Port A I/O pins are used
to have this wake-up function.
Pull-high Registers - PAPU
The I/O pins, if configured as inputs, can have internal
pull-high resistors connected, which eliminates the need
for external pull-high resistors. This register selects which
I/O pins are connected to internal pull-high resistors.
System Control Registers - CTRL0, CTRL1
These registers are used to provide control over various
internal functions. Some of these include the Buzzer
control, external Interrupt edge trigger type and Watchdog Timer enable function.
· CTRL0 Register
Bit
7
6
5
4
3
2
1
0
Name
¾
¾
¾
¾
BZEN1
BZEN0
¾
¾
R/W
¾
¾
¾
¾
R/W
R/W
¾
¾
POR
¾
¾
¾
¾
0
0
¾
¾
Bit 7~4
unimplemented, read as ²0²
Bit 3~2
BZEN1, BZEN0: BZ/BZ enable/disable
00: both disabled
01: Reserved
10: BZ only enabled
11: BZ and BZ enabled
When BZ or BZ is disabled, the I/O port will have general I/O functions. If enabled, the BZ or
BZ outputs will still be controlled by the related I/O port control and data settings. Refer to the
Buzzer Function section for details.
Bit 1~04
unimplemented, read as ²0²
· CTRL1 Register
Bit
7
6
5
4
3
2
1
0
Name
INTEG1
INTEG0
¾
¾
WDTEN3
WDTEN2
WDTEN1
WDTEN0
R/W
R/W
R/W
¾
¾
R/W
R/W
R/W
R/W
POR
1
0
¾
¾
1
0
1
0
Bit 7, 6
INTEG1, INTEG0: External interrupt edge type
00: disable
01: rising edge trigger
10: falling edge trigger
11: dual edge trigger
Bit 5, 4
unimplemented, read as ²0²
Bit 3~0
WDTEN3, WDTEN2, WDTEN1, WDTEN0: WDT function enable
1010: WDT disabled
Other values: WDT enabled - Recommended value is 0101
If the ²watchdog timer enable² configuration option is selected, then the watchdog timer will
always be enabled and the WDTEN3~WDTEN0 control bits will have no effect.
Note:
The WDT is only disabled when both the WDT configuration option is disabled and when bits
WDTEN3~WDTEN0=1010.
The WDT is enabled when either the WDT configuration option is enabled or when bits
WDTEN3~WDTEN0¹1010.
Rev. 1.00
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HT48R005/HT46R005
Oscillator
of C1 and C2 should be selected in consultation with the
crystal or resonator manufacturer¢s specification.
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.
Crystal Oscillator C1 and C2 Values
System Oscillator Overview
In addition to being the source of the main system clock
the oscillators also provide clock sources for the Watchdog Timer function. External oscillators requiring some
external components as well as a two fully integrated internal oscillators, requiring no external components, are
provided to form a wide range of both fast and slow system oscillators.
Type
Name
Freq.
External Crystal
HXT
400kHz~
12MHz
External RC
ERC
400kHz~
12MHz
Internal High Speed RC
HIRC
4, 8 or
12MHz
Internal Low Speed RC
LIRC
13kHz
C 2
O S C 2
8MHz
8pF
10pF
4MHz
8pF
10pF
1MHz
100pF
100pF
C1 and C2 values are for guidance only.
Using the ERC oscillator only requires that a resistor,
with a value between 24kW and 1.5MW, is connected
between OSC1 and VDD, and a capacitor is connected
between OSC and ground, providing a low cost oscillator configuration. It is only the external resistor that determines the oscillation frequency; the external
capacitor has no influence over the frequency and is
connected for stability purposes only. 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 resistance/frequency reference point, it can be noted that with an external 120K
resistor connected and with a 5V voltage power supply
and temperature of 25 degrees, the oscillator will have a
frequency of 4MHz within a tolerance of 2%. Here only
the OSC1 pin is used, which is shared with I/O pin PA6,
leaving pin PA5 free for use as a normal I/O pin.
V
External Crystal/Resonator Oscillator - HXT
R f
10pF
External RC Oscillator - ERC
R
The simple connection of a crystal across OSC1 and
OSC2 will create the necessary phase shift and feedback for oscillation. However, for some crystals and
most resonator types, to ensure oscillation and accurate
frequency generation, it is necessary to add two small
value external capacitors, C1 and C2. The exact values
R p
C2
8pF
Crystal Recommended Capacitor Values
There are four system oscillators. Three high speed oscillators and one low speed oscillator. The high speed
oscillators are the external crystal/ceramic oscillator HXT, the external - ERC, and the internal RC oscillator HIRC. The low speed oscillator is the internal 13kHz
(VDD=5V) oscillator - LIRC.
O S C 1
C1
12MHz
Note:
System Clock Configurations
C 1
Crystal Frequency
D D
O S C
P A 6 /O S C 1
4 7 0 p F
P A 5 /O S C 2
External RC Oscillator - ERC
In te r n a l
O s c illa to r
C ir c u it
T o in te r n a l
c ir c u its
N o te : 1 . R p is n o r m a lly n o t r e q u ir e d . C 1 a n d C 2 a r e r e q u ir e d .
2 . A lth o u g h n o t s h o w n O S C 1 /O S C 2 p in s h a v e a p a r a s itic
c a p a c ita n c e o f a r o u n d 7 p F .
Crystal/Resonator Oscillator - HXT
Rev. 1.00
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HT48R005/HT46R005
Internal RC Oscillator - HIRC
OSC1/OSC2 Configuration
Operating
Mode
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 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 PA5 and PA6 are free for use as normal I/O pins.
HXT
ERC
HIRC
Normal
Run
Run
Run
Sleep
Stop
Stop
Stop
Operating Mode Control
Mode Switching
The devices are switched between one mode and another using the HALT instruction. The HALT instruction
forces the system into the Sleep Mode.
When a HALT instruction is executed, the system enters
the Sleep mode the following conditions exist:
· The system oscillator will stop running and the appli-
cation program will stop at the ²HALT² instruction.
· The Data Memory contents and registers will maintain
P A 5 /O S C 2
P A 6 /O S C 1
their present condition.
In te rn a l R C
O s c illa to r
· The WDT will be cleared and resume counting if the
WDT clock source is selected to come from the WDT
oscillator. The WDT will stop if its clock source originates from the system clock.
N o te : P A 5 /P A 6 u s e d a s n o rm a l I/O s
Internal RC Oscillator - HIRC
· The I/O ports will maintain their present condition.
· In the status register, the Power Down flag, PDF, will
Internal Low Speed Oscillator - LIRC
be set and the Watchdog time-out flag, TO, will be
cleared.
The LIRC is a fully self-contained free running on-chip
RC oscillator with a typical frequency of 13kHz at 5V requiring no external components. When the device enters the Sleep Mode, the system clock will stop running
but the WDT oscillator continues to free-run and to keep
the watchdog active. However, to preserve power in certain applications the LIRC can be disabled via a configuration option.
Standby Current Considerations
As the main reason for entering the Sleep Mode is to
keep the current consumption of the MCU to as low a
value as possible, perhaps only in the order of several
micro-amps, there are other considerations which must
also be taken into account by the circuit designer if the
power consumption is to be minimised.
Operating Modes
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
The system can be selected to operate in two modes.
These Modes are Normal and Sleep.
f
H X T
C L K M O D
( D e te r m in e N o r m a l/
S lo w M o d e )
H X T
C o n fig u r a tio n o p tio n
f
E R C
f
H IR C
E R C
M U X
H IR C
( N o r m a l)
M U X
(S L O W
f
f
S Y S
)
L X T
L X T
C o n fig u r a tio n o p tio n
L IR C
f
L IR C
f
M U X
S Y S
T o w a tc h d o g tim e r
/4
System Clock Configurations
Rev. 1.00
21
November 29, 2011
HT48R005/HT46R005
gram will resume execution at the instruction following
the ²HALT² instruction.
increased current consumption. 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.
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 ²HALT² 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 to ²1² before entering the Sleep Mode, then any future interrupt
requests will not generate a wake-up function of the related interrupt will be ignored.
If the configuration options have enabled the Watchdog
Timer internal oscillator LIRC then this will continue to
run when in the Sleep Mode and will thus consume
some power. For power sensitive applications it may be
therefore preferable to use the system clock source for
the Watchdog Timer.
Wake-up
After the system enters the Sleep Mode, it can be woken
up from one of various sources listed as follows:
· An external reset
· An external falling edge on PA0 to PA7
No matter what the source of the wake-up event is, once
a wake-up event occurs, there will be a time delay before normal program execution resumes. Consult the table for the related time.
· A system interrupt
· A WDT overflow
If the system is woken up by an external reset, the device will experience a full system reset, however, if the
device is woken up by a WDT overflow, a Watchdog
Timer reset will be initiated. Although both of these
wake-up methods will initiate a reset operation, the actual source of the wake-up can be determined by examining the TO and PDF flags. The PDF flag is cleared by a
system power-up or executing the clear Watchdog
Timer instructions and is set when executing the ²HALT²
instruction. The TO flag is set if a WDT time-out occurs,
and causes a wake-up that only resets the Program
Counter and Stack Pointer, the other flags remain in
their original status.
Oscillator Type
Wake-up Source
External RES, Power-on
Reset and LVR
HXT
tRSTD +
tSST1
tRSTD +
tSST2
tSST1
tSST2
PA Port
Interrupt
WDT Overflow
Note:
Pins PA0 to PA7 can be setup via the PAWK register to
permit a negative transition on the pin to wake-up the
system. When a PA0 to PA7 pin wake-up occurs, the pro-
Rev. 1.00
ERC, IRC
1. tRSTD (reset delay time), tSYS (system clock)
2. tRSTD is power-on delay, typical time=100ms
3. tSST1= 2 ´ tSYS
4. tSST2= 128 ´ tSYS
Wake-up Delay Time
22
November 29, 2011
HT48R005/HT46R005
Watchdog Timer
Watchdog Timer will cease to function. For systems that
operate in noisy environments, using the LIRC as the
clock source is therefore the recommended choice. The
division ratio of the prescaler is determined by bits 0, 1
and 2 of the WDTS register, known as WS0, WS1 and
WS2. If the Watchdog Timer internal clock source is selected and with the WS0, WS1 and WS2 bits of the
WDTS register all set high, the prescaler division ratio will
be 1:128, which will give a maximum time-out period.
The Watchdog Timer, also known as the WDT, is provided to inhibit program malfunctions caused by the program jumping to unknown locations due to certain
uncontrollable external events such as electrical noise.
Watchdog Timer Operation
It operates by providing a device reset when the Watchdog Timer counter overflows. Note that if the Watchdog
Timer function is not enabled, then any instructions related to the Watchdog Timer will result in no operation.
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 Mode, when a
Watchdog Timer time-out occurs, the device will be
woken up, 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 an external
hardware reset, which means a low level on the external
reset pin, the second is using the Clear Watchdog Timer
software instructions and the third is when a HALT instruction is executed. There are two methods of using
software instructions to clear the Watchdog Timer, one
of which must be chosen by configuration option. The
first option is to use the single ²CLR WDT² instruction
while the second is to use the two commands ²CLR
WDT1² and ²CLR WDT2². For the first option, a simple
execution of ²CLR WDT² will clear the Watchdog Timer
while for the second option, both ²CLR WDT1² and
²CLR WDT2² must both be executed to successfully
clear the Watchdog Timer. Note that for this second option, if ²CLR WDT1² is used to clear the Watchdog
Timer, successive executions of this instruction will have
no effect, only the execution of a ²CLR WDT2² instruction will clear the Watchdog Timer. Similarly after the
²CLR WDT2² instruction has been executed, only a successive ²CLR WDT1² instruction can clear the Watchdog Timer.
Setting up the various Watchdog Timer options are controlled via the configuration options and two internal registers WDTS and CTRL1. Enabling the Watchdog Timer
can be controlled by both a configuration option and the
WDTEN bits in the CTRL1 internal register in the Data
Memory.
Configuration
Option
CTRL1
Register
WDT
Function
Disable
Disable
OFF
Disable
Enable
ON
Enable
x
ON
Watchdog Timer On/Off Control
The Watchdog Timer will be disabled if bits
WDTEN3~WDTEN0 in the CTRL1 register are written
with the binary value 1010B and WDT configuration option is disable. This will be the condition when the device
is powered up. Although any other data written to
WDTEN3~WDTEN0 will ensure that the Watchdog
Timer is enabled, for maximum protection it is recommended that the value 0101B is written to these bits.
The Watchdog Timer clock can emanate from three different sources, selected by configuration option. These
are fSYS/4, or LIRC. It is important to note that when the
system enters the Sleep Mode the instruction clock is
stopped, therefore if the configuration options have selected fSYS/4 as the Watchdog Timer clock source, the
C L R
W D T 1 F la g
C L R
W D T 2 F la g
C le a r W D T T y p e
C o n fig u r a tio n O p tio n
1 o r 2 In s tr u c tio n s
fS
Y S
/4
L IR C
C L R
C o n fig .
O p tio n
S e le c t
fW
D T C K
W D T C lo c k S o u r c e S e le c tio n
1 5 s ta g e c o u n te r
W D T T im e - o u t
W S 2 ~ W S 0
Watchdog Timer
Rev. 1.00
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November 29, 2011
HT48R005/HT46R005
· WDTS Register
Bit
7
6
5
4
3
2
1
0
Name
¾
¾
¾
¾
¾
WS2
WS1
WS0
R/W
¾
¾
¾
¾
¾
R/W
R/W
R/W
POR
¾
¾
¾
¾
¾
1
1
1
Bit 7~3 :
unimplemented, read as ²0²
Bit 2~0
WS2, WS1, WS0: WDT time-out period selection
000: 28 tWDTCK
001: 29 tWDTCK
010: 210 tWDTCK
011: 211 tWDTCK
100: 212 tWDTCK
101: 213 tWDTCK
110: 214 tWDTCK
111: 215 tWDTCK
Reset and Initialisation
· Power-on Reset
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.
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.
Although the microcontroller has an internal RC reset
function, if the VDD power supply rise time is not fast
enough or does not stabilise quickly at power-on, the
internal reset function may be incapable of providing
proper reset operation. For this reason it is recommended that an external RC network is connected to
the RES pin, whose additional time delay will ensure
that the RES pin remains low for an extended period
to allow the power supply to stabilise. During this time
delay, normal operation of the microcontroller will be
inhibited. After the RES line reaches a certain voltage
value, the reset delay time tRSTD is invoked to provide
an extra delay time after which the microcontroller will
begin normal operation. The abbreviation SST in the
figures stands for System Start-up Timer.
In addition to the power-on reset, situations may arise
where it is necessary to forcefully apply a reset condition
when the microcontroller is running. One example of this
is where after power has been applied and the
microcontroller is already running, the RES line is forcefully pulled low. In such a case, known as a normal operation reset, some of the microcontroller registers remain
unchanged allowing the microcontroller to proceed with
normal operation after the reset line is allowed to return
high. 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.
V D D
R E S
D D
t RR
SS TT DD ++
t SS
SS TT
In te rn a l R e s e t
Another reset exists in the form of a Low Voltage Reset,
LVR, where a full reset, similar to the RES reset is implemented in situations where the power supply voltage
falls below a certain threshold.
Note: tRSTD is power-on delay, typical time=100ms
Power-On Reset Timing Chart
For most applications a resistor connected between
VDD and the RES pin and a capacitor connected between VSS and the RES pin will provide a suitable external reset circuit. Any wiring connected to the RES
pin should be kept as short as possible to minimise
any stray noise interference.
Reset Functions
There are five ways in which a microcontroller reset can
occur, through events occurring both internally and externally:
Rev. 1.00
0 .9 V
24
November 29, 2011
HT48R005/HT46R005
will ignore the low supply voltage and will not perform
a reset function. The actual VLVR value can be selected via configuration options.
For applications that operate within an environment
where more noise is present the Enhanced Reset Circuit shown is recommended.
V
· Watchdog Time-out Reset during Normal Operation
D D
0 .0 1 m F * *
The Watchdog time-out Reset during normal operation is the same as a hardware RES pin reset except
that the Watchdog time-out flag TO will be set to ²1².
V D D
1 N 4 1 4 8 *
1 0 k W ~
1 0 0 k W
W D T T im e - o u t
tR
R E S /P A 7
3 0 0 W *
S T
WDT Time-out Reset during Normal Operation
Timing Chart
²*² It is recommended that this component is
added for added ESD protection
²**² It is recommended that this component is
added in environments where power line noise
is significant
· Watchdog Time-out Reset during Sleep mode
The Watchdog time-out Reset during Sleep 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
²0² and the TO flag will be set to ²1². Refer to the A.C.
Characteristics for tSST details.
External RES Circuit
W D T T im e - o u t
More information regarding external reset circuits is
located in Application Note HA0075E on the Holtek
website.
tS
WDT Time-out Reset during Sleep
Timing Chart
This type of reset occurs when the microcontroller is
already running and the RES pin is forcefully pulled
low by external hardware such as an external switch.
In this case as in the case of other reset, the Program
Counter will reset to zero and program execution initiated from this point.
0 .9 V
S T
In te rn a l R e s e t
· RES Pin Reset
0 .4 V
tS
Note: tRSTD is power-on delay, typical time=100ms
V S S
R E S
+
In te rn a l R e s e t
0 .1 ~ 1 m F
Note:
S T D
Note:
If the system clock source is provided by ERC
or HIRC, the tSST is 2 clock cycles.
If the system clock source is provided by HXT,
the tSST is 128 clock cycles.
D D
Reset Initial Conditions
D D
tR
S T D
+
tS
S T
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
function or Watchdog Timer. The reset flags are shown
in the table:
In te rn a l R e s e t
Note: tRSTD is power-on delay, typical time=100ms
RES Reset Timing Chart
· Low Voltage Reset - LVR
The microcontroller contains a low voltage reset circuit in order to monitor the supply voltage of the device. The LVR function is selected via a configuration
option. If the supply voltage of the device drops to
within a range of 0.9V~VLVR such as might occur when
changing the battery, the LVR will automatically reset
the device internally. 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
TO
PDF
RESET Conditions
0
0
Power-on reset
u
u
RES or LVR reset during Normal Mode
operation
1
u
WDT time-out reset during Normal Mode
operation
1
1
WDT time-out reset during Sleep Mode
operation
Note: ²u² stands for unchanged
L V R
tR
S T D
+
tS
S T
In te rn a l R e s e t
Note: tRSTD is power-on delay, typical time=100ms
Low Voltage Reset Timing Chart
Rev. 1.00
25
November 29, 2011
HT48R005/HT46R005
The following table indicates the way in which the various components of the microcontroller are affected after a
power-on reset occurs.
Item
Condition After RESET
Program Counter
Reset to zero
Interrupts
All interrupts will be disabled
WDT
Clear after reset, WDT begins counting
Timer/Event Counter
Timer Counter will be turned off
Prescaler
The Timer Counter Prescaler will be cleared
Input/Output Ports
I/O ports will be setup as inputs
Stack Pointer
Stack Pointer will point to the top of the stack
The different kinds of resets all affect the internal registers of the microcontroller in different ways. To ensure reliable
continuation of normal program execution after a reset occurs, it is important to know what condition the microcontroller
is in after a particular reset occurs. The following table describes how each type of reset affects each of the
microcontroller internal registers.
HT48R005
Register
Power-on
Reset
RES or LVR
Reset
WDT Time-out
(Normal Operation)
WDT Time-out
(HALT Mode)
PCL
0000 0000
0000 0000
0000 0000
0000 0000
MP0
1xxx xxxx
1uuu uuuu
1uuu uuuu
1uuu uuuu
MP1
1xxx xxxx
1uuu uuuu
1uuu uuuu
1uuu uuuu
ACC
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
TBLP
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
TBLH
--xx xxxx
--uu uuuu
--uu uuuu
--uu uuuu
WDTS
---- -111
---- -111
---- -111
---- -uuu
STATUS
--00 xxxx
--uu uuuu
--1u uuuu
--11 uuuu
INTC0
--00 -000
--00 -000
--00 -000
--uu -uuu
TMR0
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
TMR0C
00-0 1000
00-0 1000
00-0 1000
uu-u uuuu
PA
111- -111
111- -111
111- -111
uuu- -uuu
PAC
111- -111
111- -111
111- -111
uuu- -uuu
PAWK
000- -000
000- -000
000- -000
uuu- -uuu
PAPU
-00- -000
-00- -000
-00- -000
-uu- -uuu
CTRL0
---- 00--
---- 00--
---- 00--
---- uu--
CTRL1
10-- 1010
10-- 1010
10-- 1010
uu-- uuuu
Note:
²-² not implemented
²u² means ²unchanged²
²x² means ²unknown²
Rev. 1.00
26
November 29, 2011
HT48R005/HT46R005
HT46R005
Register
Power-on
Reset
RES or LVR
Reset
WDT Time-out
(Normal Operation)
WDT Time-out
(HALT Mode)
PCL
0000 0000
0000 0000
0000 0000
0000 0000
MP0
1xxx xxxx
1uuu uuuu
1uuu uuuu
1uuu uuuu
MP1
1xxx xxxx
1uuu uuuu
1uuu uuuu
1uuu uuuu
ACC
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
TBLP
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
TBLH
--xx xxxx
--uu uuuu
--uu uuuu
--uu uuuu
WDTS
---- -111
---- -111
---- -111
---- -uuu
STATUS
--00 xxxx
--uu uuuu
--1u uuuu
--11 uuuu
INTC0
-000 0000
-000 0000
-000 0000
-uuu uuuu
TMR0
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
TMR0C
00-0 1000
00-0 1000
00-0 1000
uu-u uuuu
PA
111- -111
111- -111
111- -111
uuu- -uuu
PAC
111- -111
111- -111
111- -111
uuu- -uuu
PAWK
000- -000
000- -000
000- -000
uuu- -uuu
PAPU
-00- -000
-00- -000
-00- -000
-uu- -uuu
CTRL0
---- 00--
---- 00--
---- 00--
---- uu--
CTRL1
10-- 1010
10-- 1010
10-- 1010
uu-- uuuu
ADRL
xxxx ----
xxxx ----
xxxx ----
uuuu ----
ADRH
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
ADCR
01-0 0000
01-0 0000
01-0 0000
uu-u uuuu
ACSR
11-- -000
11-- -000
11-- -000
uu-- -uuu
Note:
²-² not implemented
²u² means ²unchanged²
²x² means ²unknown²
Rev. 1.00
27
November 29, 2011
HT48R005/HT46R005
Input/Output Ports
Holtek microcontrollers offer considerable flexibility on
their I/O ports. Most pins can have either an input or output designation under user program control. Additionally, as there are pull-high resistors and wake-up
software configurations, the user is provided with an I/O
structure to meet the needs of a wide range of application possibilities.
Port A Wake-up
If the HALT instruction is executed, the device will enter
the Sleep Mode, where the system clock will stop resulting in power being conserved, 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
PA0~PA2, PA5~PA7 pins from high to low. After a HALT
instruction forces the microcontroller into entering the
Sleep Mode, the processor will remain in a low-power
state until the logic condition of the selected wake-up pin
on Port A changes from high to low. This function is especially suitable for applications that can be woken up
via external switches. Note that pins PA0~PA2,
PA5~PA7 can be selected individually to have this
wake-up feature using an internal register known as
PAWK, located in the Data Memory.
For input operation, these ports are non-latching, which
means the inputs must be ready at the T2 rising edge of
instruction ²MOV A,[m]², where m denotes the port address. For output operation, all the data is latched and
remains unchanged until the output latch is rewritten.
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, when configured as an input have the capability of
being connected to an internal pull-high resistor. These
pull-high resistors are selectable via a register known as
PAPU located in the Data Memory. The pull-high resistors are implemented using weak PMOS transistors.
Note that pin PA7 does not have a pull-high resistor selection.
· PAWK, PAC, PAPU Register
Register
Name
POR
Bit
7
6
5
4
3
2
1
0
PAWK
00H
PAWK7
PAWK6
PAWK5
¾
¾
PAWK2
PAWK1
PAWK0
PAC
FFH
PAC7
PAC6
PAC5
¾
¾
PAC2
PAC1
PAC0
PAPU
00H
¾
PAPU6
PAPU5
¾
¾
PAPU2
PAPU1
PAPU0
²¾² Unimplemented, read as ²0²
PAWKn: PA wake-up function enable
0: disable
1: enable
PACn: I/O type selection
0: output
1: input
PAPUn: Pull-high function enable
0: disable
1: enable
Rev. 1.00
28
November 29, 2011
HT48R005/HT46R005
I/O Port Control Registers
as normal logic input with the usual pull-high selection, even if the Buzzer function has been selected.
Each Port has its own control register, known as PAC
which controls the input/output configuration. With this
control register, each I/O pin with or without pull-high resistors can be reconfigured dynamically under software
control. For the I/O pin to function as an input, the corresponding bit of the control register must be written as a
²1². This will then allow the logic state of the input pin to
be directly read by instructions. When the corresponding bit of the control register is written as a ²0², 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.
· A/D Inputs
Each device in this series has either four or eight inputs to the A/D converter. All of these analog inputs
are pin-shared with I/O pins on Port A. If these pins
are to be used as A/D inputs and not as I/O pins then
the corresponding PCRn bits in the A/D converter
control register, ADCR, must be properly setup. There
are no configuration options associated with the A/D
converter. If chosen as I/O pins, then full pull-high resistor configuration options remain, however if used
as A/D inputs then any pull-high resistor configuration
options associated with these pins will be automatically disconnected.
I/O Pin Structures
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.
Pin-shared Functions
The flexibility of the microcontroller range is greatly enhanced by the use of pins that have more than one function. Limited numbers of pins can force serious design
constraints on designers but by supplying pins with
multi-functions, many of these difficulties can be overcome. For some pins, the chosen function of the
multi-function I/O pins is set by configuration options
while for others the function is set by application program control.
Programming Considerations
Within the user program, one of the first things to consider is port initialisation. After a reset, the I/O data register and I/O port control register 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 options have been selected. If the
port control registers, are then programmed to setup
some pins as outputs, these output pins will have an initial high output value unless the associated port data
register is first programmed. Selecting which pins are inputs and which are outputs can be achieved byte-wide
by loading the correct value into the port control register
or by programming individual bits in the port control register using the ²SET [m].i² and ²CLR [m].i² 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.
· External Interrupt Input
The external interrupt pin, INT, is pin-shared with an
I/O pin. To use the pin as an external interrupt input
the correct bits in the INTC0 register must be programmed. The pin must also be setup as an input by
setting PAC2 bit in the Port Control Register. A
pull-high resistor can also be selected via the appropriate port pull-high resistor register. Note that even if
the pin is setup as an external interrupt input the I/O
function still remains.
· External Timer/Event Counter Input
The Timer/Event Counter pin, TMR is pin-shared with
I/O pin. For this shared pin to be used as Timer/Event
Counter input, the Timer/Event Counter must be configured to be in the Event Counter or Pulse Width Capture Mode. This is achieved by setting the appropriate
bits in the Timer/Event Counter Control Register. The
pins must also be setup as inputs by setting the appropriate bit in the Port Control Register. Pull-high resistor options can also be selected using the port
pull-high resistor registers. Note that even if the pin is
setup as an external timer input the I/O function still remains.
T 1
S y s te m
T 3
T 4
T 1
T 2
T 3
T 4
P o rt D a ta
R e a d fro m
P o rt
W r ite to P o r t
Read Modify Write Timing
· Buzzer Output
Pins PA0 to PA7 each have a wake-up functions, selected via the PAWK register. When the device is in the
Sleep Mode, various methods are available to wake the
device up. One of these is a high to low transition of any
of the these pins. Single or multiple pins on Port A can
be setup to have this function.
The device contains a Buzzer function whose single
or dual outputs are pin-shared with I/O pins. The output function of these pin are chosen using the CTRL0
register. Note that the corresponding bit of the port
control register, must setup the pin as an output to enable the BZ, BZ output. If the port control register has
setup these pins as input, then these pins will function
Rev. 1.00
T 2
C lo c k
29
November 29, 2011
HT48R005/HT46R005
V
P u ll- H ig h
S e le c t
C o n tr o l B it
D a ta B u s
Q
D
W r ite C o n tr o l R e g is te r
W e a k
P u ll- u p
Q
C K
S
C h ip R e s e t
I/O
R e a d C o n tr o l R e g is te r
p in
D a ta B it
Q
D
W r ite D a ta R e g is te r
C K
Q
S
M
R e a d D a ta R e g is te r
S y s te m
D D
U
X
P A o n ly
W a k e -u p
W a k e - u p S e le c t
Generic Input/Output Ports
D a ta B u s
W r ite C o n tr o l R e g is te r
C o n tr o l B it
Q
D
C K
Q
S
C h ip R e s e t
P A 7 /R E S
R e a d C o n tr o l R e g is te r
D a ta B it
Q
D
W r ite D a ta R e g is te r
C K
S
Q
M
R e a d D a ta R e g is te r
S y s te m
U
X
W a k e -u p (P A 7 )
P A W K 7
R E S fo r P A 7 o n ly
PA7 NMOS Input/Output Port
Rev. 1.00
30
November 29, 2011
HT48R005/HT46R005
Timer/Event Counters
where the actual timer value is stored. This register is
known as TMR0. The value in the timer registers increases by one each time an internal clock pulse is received or an external transition occurs on the external
timer pin. The timer will count from the initial value
loaded by the preload register to the full count of FFH at
which point the timer overflows and an internal interrupt
signal is generated. The timer value will then be reset
with the initial preload register value and continue counting.
The provision of timers form an important part of any
microcontroller, giving the designer a means of carrying
out time related functions. The devices contain from one
count-up timer of 8-bit capacity. As the timer has three
different operating modes, it can be configured to operate as a general timer, an external event counter or as a
pulse width capture device. The provision of an internal
prescaler to the clock circuitry on gives added range to
the timer.
There are two types of registers related to the
Timer/Event Counters. The first is the register that contains the actual value of the timer and into which an initial value can be preloaded. Reading from this register
retrieves the contents of the Timer/Event Counter. The
second type of associated register is the Timer Control
Register which defines the timer options and determines how the timer is to be used. The device can have
the timer clock configured to come from the internal
clock source. In addition, the timer clock source can also
be configured to come from an external timer pin.
Note that to achieve a maximum full range count of FFH,
the preload register must first be cleared to all zeros. It
should be noted that after power-on, the preload registers will be in an unknown condition. Note that if the
Timer/Event Counter is in an OFF condition and data is
written to its preload register, this data will be immediately written into the actual counter. However, if the
counter is enabled and counting, any new data written
into the preload data register during this period will remain in the preload register and will only be written into
the actual counter the next time an overflow occurs.
Configuring the Timer/Event Counter Input Clock
Source
Timer Control Registers - TMR0C
The Timer/Event Counter clock source can originate
from various sources, an internal clock or an external
pin. The internal clock source source is used when the
timer is in the timer mode or in the pulse width capture
mode. For some Timer/Event Counters, this internal
clock source is first divided by a prescaler, the division
ratio of which is conditioned by the Timer Control Register bits T0PSC0~T0PSC2. For Timer/Event Counter,
the internal clock source is fro the fSYS.
The flexible features of the Holtek microcontroller
Timer/Event Counters enable them to operate in three
different modes, the options of which are determined by
the contents of their respective control register.
The Timer Control Register is known as TMR0C. It is the
Timer Control Register together with its corresponding
timer register that control the full operation of the
Timer/Event Counter. Before the timer can be used, it is
essential that the Timer Control Register is fully programmed with the right data to ensure its correct operation, a process that is normally carried out during
program initialisation.
An external clock source is used when the timer is in the
event counting mode, the clock source being provided
on an external timer pin TMR. Depending upon the condition of the T0EG bit, each high to low, or low to high
transition on the external timer pin will increment the
counter by one.
To choose which of the three modes the timer is to operate in, either in the timer mode, the event counting mode
or the pulse width capture mode, bits 7 and 6 of the
Timer Control Register, which are known as the bit pair
T0M1/T0M0, must be set to the required logic levels.
The timer-on bit, which is bit 4 of the Timer Control Register and known as T0ON, provides the basic on/off con-
Timer Registers - TMR
The timer register is special function register located in
the Special Purpose Data Memory and is the place
D a ta B u s
P r e lo a d R e g is te r
T 0 P S C 2 ~ T 0 P S C 0
fS
P r e s c a le r
Y S
T 0 M 1
R e lo a d
T 0 M 0
T im e r /E v e n t
C o u n te r
T im e r /E v e n t C o u n te r
M o d e C o n tro l
T M R
T 0 O N
O v e r flo w
to In te rru p t
¸ 2
B u z z e r
T 0 E
8-bit Timer/Event Counter Structure
Rev. 1.00
31
November 29, 2011
HT48R005/HT46R005
· TMR0C Register
Bit
7
6
5
4
3
2
1
0
Name
T0M1
T0M0
¾
T0ON
T0EG
T0PSC2
T0PSC1
T0PSC0
R/W
R/W
R/W
¾
R/W
R/W
R/W
R/W
R/W
POR
0
0
¾
0
1
0
0
0
Bit 7,6
T0M1, T0M0: Timer operation mode selection
00: no mode available
01: event counter mode
10: timer mode
11: pulse width capture mode
Bit 5
Unimplemented, read as ²0²
Bit 4
T0ON: Timer/event counter counting enable
0: disable
1: enable
Bit 3
T0EG:
Event counter active edge selection
0: count on raising edge
1: count on falling edge
Pulse Width Capture active edge selection
0: start counting on falling edge, stop on rasing edge
1: start counting on raising edge, stop on falling edge
Bit 2~0
T0PSC2, T0PSC1, T0PSC0: Timer prescaler rate selection
Timer internal clock=
000: fTP
001: fTP/2
010: fTP/4
011: fTP/8
100: fTP/16
101: fTP/32
110: fTP/64
111: fTP/128
Rev. 1.00
32
November 29, 2011
HT48R005/HT46R005
trol of the respective timer. Setting the bit high allows the
counter to run, clearing the bit stops the counter. Bits
0~2 of the Timer Control Register determine the division
ratio of the input clock prescaler. The prescaler bit settings have no effect if an external clock source is used. If
the timer is in the event count or pulse width capture
mode, the active transition edge level type is selected by
the logic level of bit 3 of the Timer Control Register
which is known as T0EG.
Control Register Operating Mode
Select Bits for the Event Counter Mode
In this mode, the Timer/Event Counter can be utilised to
measure fixed time intervals, providing an internal interrupt signal each time the Timer/Event Counter overflows. To operate in this mode, the Operating Mode
Select bit pair, T0M1/T0M0, in the Timer Control Register must be set to the correct value as shown.
Bit7 Bit6
1
0
1
In this mode, the external timer TMR pin, is used as the
Timer/Event Counter clock source, however it is not divided by the internal prescaler. After the other bits in the
Timer Control Register have been setup, the enable bit
T0ON, which is bit 4 of the Timer Control Register, can
be set high to enable the Timer/Event Counter to run. If
the Active Edge Select bit, T0EG, which is bit 3 of the
Timer Control Register, is low, the Timer/Event Counter
will increment each time the external timer pin receives
a low to high transition. If the T0EG is high, the counter
will increment each time the external timer pin receives
a high to low transition. When it is full and overflows, an
interrupt signal is generated and the Timer/Event Counter will reload the value already loaded into the preload
register and continue counting. The interrupt can be disabled by ensuring that the Timer/Event Counter Interrupt Enable bit in the corresponding Interrupt Control
Register, is reset to zero.
Timer Mode
Control Register Operating Mode
Select Bits for the Timer Mode
Bit7 Bit6
0
In this mode the internal clock is used as the timer clock.
The timer input clock source is either fSYS or fSYS/4.
However, this timer clock source is further divided by a
prescaler, the value of which is determined by the bits
T0PSC2~T0PSC0 in the Timer Control Register. The
timer-on bit, T0ON must be set high to enable the timer
to run. Each time an internal clock high to low transition
occurs, the timer increments by one; when the timer is
full and overflows, an interrupt signal is generated and
the timer will reload the value already loaded into the
preload register and continue counting. A timer overflow
condition and corresponding internal interrupt is one of
the wake-up sources, however, the internal interrupts
can be disabled by ensuring that the T0EG bits of the
INTC0 register are reset to zero.
As the external timer pin is shared with an I/O pin, to ensure that the pin is configured to operate as an event
counter input pin, two things have to happen. The first is
to ensure that the Operating Mode Select bits in the
Timer Control Register place the Timer/Event Counter in
the Event Counting Mode, the second is to ensure that
the port control register configures the pin as an input. It
should be noted that in the event counting mode, even if
t h e microcontroller i s i n t h e S l e e p M o d e , t h e
Timer/Event Counter will continue to record externally
changing logic events on the timer input TMR pin. As a
result when the timer overflows it will generate a timer
interrupt and corresponding wake-up source.
Event Counter Mode
In this mode, the Timer/Event Counter can be utilised to
measure the width of external pulses applied to the external timer pin. To operate in this mode, the Operating
Mode Select bit pair, T0M1/T0M0, in the Timer Control
Register must be set to the correct value as shown.
Pulse Width Capture Mode
In this mode, a number of externally changing logic
events, occurring on the external timer TMR pin, can be
recorded by the Timer/Event Counter. To operate in this
mode, the Operating Mode Select bit pair, T0M1/T0M0,
in the Timer Control Register must be set to the correct
value as shown.
P r e s c a le r O u tp u t
In c re m e n t
T im e r C o n tr o lle r
T im e r + 1
T im e r + 2
T im e r + N
T im e r + N + 1
Timer Mode Timing Chart
E x te rn a l E v e n t
In c re m e n t
T im e r C o u n te r
T im e r + 1
T im e r + 2
T im e r + 3
Event Counter Mode Timing Chart (T0EG=1)
Rev. 1.00
33
November 29, 2011
HT48R005/HT46R005
Control Register Operating Mode
Select Bits for the Pulse Width
Capture Mode
ated and the Timer/Event Counter will reload the value already loaded into the preload register and continue
counting. The interrupt can be disabled by ensuring that
the Timer/Event Counter Interrupt Enable bit in the corresponding Interrupt Control Register, is reset to zero.
Bit7 Bit6
1
1
In this mode the internal clock, fSYS or fSYS/4, is used as
the internal clock for the 8-bit Timer/Event Counter.
However, the clock source, fSYS, for the 8-bit timer is further divided by a prescaler, the value of which is determ in e d b y t h e P r es c al e r R a t e S e l e ct b i t s
T0PSC2~T0PSC0, which are bits 2~0 in the Timer Control Register. After the other bits in the Timer Control
Register have been setup, the enable bit T0ON, which is
bit 4 of the Timer Control Register, can be set high to enable the Timer/Event Counter, however it will not actually start counting until an active edge is received on the
external timer pin.
As the TMR pin is shared with an I/O pin, to ensure that
the pin is configured to operate as a pulse width capture
pin, two things have to happen. The first is to ensure that
the Operating Mode Select bits in the Timer Control
Register place the Timer/Event Counter in the pulse
width capture Mode, the second is to ensure that the
port control register configures the pin as an input.
Prescaler
Bits T0PSC0~T0PSC2 of the TMRC register can be
used to define a division ratio for the internal clock
source of the Timer/Event Counter enabling longer time
out periods to be setup.
If the Active Edge Select bit T0EG, which is bit 3 of the
Timer Control Register, is low, once a high to low transition has been received on the external timer pin, the
Timer/Event Counter will start counting until the external
timer pin returns to its original high level. At this point the
enable bit will be automatically reset to zero and the
Timer/Event Counter will stop counting. If the Active
Edge Select bit is high, the Timer/Event Counter will begin counting once a low to high transition has been received on the external timer pin and stop counting when
the external timer pin returns to its original low level. As
before, the enable bit will be automatically reset to zero
and the Timer/Event Counter will stop counting. It is important to note that in the pulse width capture Mode, the
enable bit is automatically reset to zero when the external control signal on the external timer pin returns to its
original level, whereas in the other two modes the enable bit can only be reset to zero under program control.
PFD Function
Operating similar to a programmable frequency divider,
the buzzer function within the microcontroller provides a
means of producing a variable frequency output suitable
for applications, such as piezo-buzzer driving or other
interfaces requiring a precise frequency generator.
BZ and BZ pins are a complimentary pair and
pin-shared with I/O pins, PA0 and PA1. The function is
selected via the CTRL0 register, however, if not selected, the pins can operate as normal I/O pins. Note
that the BZ pin is the inverse of the BZ pin generating a
kind of differential output and supplying more power to
connected interfaces such as buzzers. The CTRL0 register can select a single BZ pin or the complimentary pair
BZ and BZ. The accompanying table illustrates the truth
table of PA0/BZ and PA1/BZ.
The residual value in the Timer/Event Counter, which
can now be read by the program, therefore represents
the length of the pulse received on the TMR pin. As the
enable bit has now been reset, any further transitions on
the external timer pin will be ignored. The timer cannot
begin further pulse width capture until the enable bit is
set high again by the program. In this way, single shot
pulse measurements can be easily made.
The timer overflow signal is the clock source for the
buzzer circuit. The output frequency is controlled by loading the required values into the timer prescaler and timer
registers to give the required division ratio. The counter
will begin to count-up from this preload register value until
full, at which point an overflow signal is generated, causing both the BZ and BZ outputs to change state. The
counter will then be automatically reloaded with the
preload register value and continue counting-up.
It should be noted that in this mode the Timer/Event
Counter is controlled by logical transitions on the external
timer pin and not by the logic level. When the Timer/Event
Counter is full and overflows, an interrupt signal is generE x te rn a l T M R
P in In p u t
T 0 O N
- w ith T 0 E G = 0
P r e s c a le r O u tp u t
In c re m e n t
T im e r C o u n te r
+ 1
T im e r
+ 2
+ 3
+ 4
P r e s c a le r O u tp u t is s a m p le d a t e v e r y fa llin g e d g e o f T 1 .
Pulse Width Capture Mode Timing Chart (TnEG=0)
Rev. 1.00
34
November 29, 2011
HT48R005/HT46R005
ment mode. Additionally the corresponding PAC Port
Control Register bit must be set high to ensure that the
pin is setup as an input. Any pull-high resistor connected
to this pin will remain valid even if the pin is used as a
Timer/Event Counter input.
If the CTRL0 register has selected the buzzer function,
then for both buzzer outputs to operate, it is essential
that the Port A control register PAC bit 0 and PAC bit 1
are setup as outputs. If only one pin is setup as an output, the other pin can still be used as a normal data input
pin. However, if both pins are setup as inputs then the
buzzer will not function. The buzzer outputs will only be
activated if bit PA0 is set to ²1². This output data bit is
used as the on/off control bit for the buzzer outputs.
Programming Considerations
When configured to run in the timer mode, the internal
system clock is used as the timer clock source and is
therefore synchronised with the overall operation of the
microcontroller. In this mode when the appropriate timer
register is full, the microcontroller will generate an internal interrupt signal directing the program flow to the respective internal interrupt vector. For the pulse width
measurement mode, the internal system clock is also
used as the timer clock source but the timer will only run
when the correct logic condition appears on the external
timer input pin. As this is an external event and not synch r o n i ze d w i t h t h e i n t e r n a l t i m e r cl o ck, t h e
microcontroller will only see this external event when the
next timer clock pulse arrives. As a result, there may be
small differences in measured values requiring programmers to take this into account during programming.
The same applies if the timer is configured to be in the
event counting mode, which again is an external event
and not synchronized with the internal system or timer
clock.
Note that the BZ and BZ outputs will both be low if the
PA0 output data bit is cleared to ²0². The condition of
data bit PA1 has no effect on the overall control of the BZ
and BZ pins.
Using this method of frequency generation, and if a
crystal oscillator is used for the system clock, very precise values of frequency can be generated.
I/O Interfacing
The Timer/Event Counter, when configured to run in the
event counter or pulse width measurement mode, requires the use of an external timer pin for its operation.
As this pin is a shared pin it must be configured correctly
to ensure that it is setup for use as a Timer/Event Counter input pin. This is achieved by ensuring that the mode
select bits in the Timer/Event Counter control register,
select either the event counter or pulse width measure-
BZEN1
BZEN0
PAC Register
PAC0
PAC Register
PAC1
PA Register
PA0
PA Register
PA1
I
I
O
O
I
x
PA0=BZ, PA1=BZ
I
I
O
O
O
x
PA0=0, PA1=0
I
O
O
I
I
x
PA0=BZ, PA1=input
Output Function
I
x
O
I
O
x
PA0=0, PA1=input
x
C
I
I
x
D
PA0=input, PA1=D
x
x
I
I
x
x
PA0=input, PA1=input
Note:
The BZEN1 and BZEN0 bits are located in the CTRL0 register; ²I²: Input; ²O²: Output;
²×² don¢t care; ²D²: data ²0² or ²1²; ²C²: CMOS output structure.
PA0/PA1 I/O Funcion Control
T im e r O v e r flo w
B u z z e r C lo c k
P A 0 D a ta
B Z O u tp u t a t P A 0
B Z O u tp u t a t P A 1
Buzzer Function
Rev. 1.00
35
November 29, 2011
HT48R005/HT46R005
When the Timer/Event Counter is read, or if data is written to the preload register, the clock is inhibited to avoid
errors, however as this may result in a counting error,
this should be taken into account by the programmer.
Care must be taken to ensure that the timers are properly initialised before using them for the first time. The
associated timer enable bits in the interrupt control register must be properly set otherwise the internal interrupt
associated with the timer will remain inactive. The edge
select, timer mode and clock source control bits in timer
control register must also be correctly set to ensure the
timer is properly configured for the required application.
It is also important to ensure that an initial value is first
loaded into the timer registers before the timer is
switched on; this is because after power-on the initial
values of the timer registers are unknown. After the
timer has been initialized the timer can be turned on and
off by controlling the enable bit in the timer control register.
generate a wake-up signal if the device is in a
Power-down condition. This situation may occur if the
Timer/Event Counter is in the Event Counting Mode and
if the external signal continues to change state. In such
a case, the Timer/Event Counter will continue to count
these external events and if an overflow occurs the device will be woken up from its Power-down condition. To
prevent such a wake-up from occurring, the timer interrupt request flag should first be set high before issuing
the ²HALT² instruction to enter the Power Down Mode.
Timer Program Example
The program shows how the Timer/Event Counter registers are setup along with how the interrupts are enabled
and managed. Note how the Timer/Event Counter is
turned on, by setting bit 4 of the Timer Control Register.
The Timer/Event Counter can be turned off in a similar
way by clearing the same bit. This example program
sets the Timer/Event Counters to be in the timer mode,
which uses the internal system clock as their clock
source.
When the Timer/Event Counter overflows, its corresponding interrupt request flag in the interrupt control
register will be set. If the Timer/Event Counter interrupt
is enabled this will in turn generate an interrupt signal.
However irrespective of whether the interrupts are enabled or not, a Timer/Event Counter overflow will also
· PFD Programming Example
org
04h
; external interrupt vector
org
08h
; Timer Counter interrupt vector
Jmp
tmr0int
; jump here when Timer overflows
:
:
org
20h
; main program
:
:
;internal Timer interrupt routine
tmr0int:
:
; Timer main program placed here
:
:
begin:
;setup
mov
mov
mov
mov
;setup
mov
mov
:
set
:
Rev. 1.00
Timer registers
a,09bh
; setup Timer preload value
tmr0,a
a,081h
; setup Timer control register
tmr0c,a
; timer mode and prescaler set to /2
interrupt register
a,005h
; enable master interrupt and timer interrupt
intc0,a
:
tmr0c.4
; start Timer
:
36
November 29, 2011
HT48R005/HT46R005
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 Converter Register Description
Overall operation of the A/D converter is controlled using four registers. A read only register pair exists to store
the ADC data 12-bit value. The remaining two registers
are control registers which setup the operating and control function of the A/D converter.
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. Only the high byte register, ADRH,
utilises its full 8-bit contents. The low byte register utilises only 4 bit of its 8-bit contents as it contains only the
lowest bits of the 12-bit converted value. In the following
table, D0~D11 is the A/D conversion data result bits.
A/D Overview
The HT46R005 contains a 3-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 either a
12-bit digital value.
The accompanying block diagram shows the overall internal structure of the A/D converter, together with its associated registers.
In the following table, D0~D11 is the A/D conversion data result bits.
Register
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
ADRL
D3
D2
D1
D0
¾
¾
¾
¾
ADRH
D11
D10
D9
D8
D7
D6
D5
D4
ADCR
START
EOCB
¾
PCR2
PCR1
PCR0
ACS1
ACS0
ACSR
TEST
ADONB
¾
¾
¾
ADCS2
ADCS1
ADCS0
A/D Data Registers
fS
A C S R
Y S
C lo c k
D iv id e r
¸ N
R e g is te r
A D O N B B it
A /D E n a b le
V
D D
A D O N
B it
P A 0 /A N 0
P A 1 /A N 1
A D R L
A D C
A D R H
P A 2 /A N 2
A /D D a ta
R e g is te r s
A C S R
R e g is te r
P C R 0 ~ P C R 2
P in C o n fig u r a tio n
B its
A D C S 0 ~ A D C S 2
C h a n n e l S e le c t
B its
S T A R T
E O C B
A D C R
R e g is te r
S ta r t B it E n d o f
C o n v e r s io n B it
A/D Converter Structure
Rev. 1.00
37
November 29, 2011
HT48R005/HT46R005
A/D Converter Control Registers - ADCR, ACSR
The PCR2~PCR0 bits in the ADCR register define the
channel number. As the device contains only one actual
analog to digital converter circuit, each of the individual
3 analog inputs must be routed to the converter. It is the
function of the ACS1~ACS0 bits in the ADCR register to
determine which analog channel is actually connected
to the internal A/D converter.
To control the function and operation of the A/D converter, two control registers known as ADCR and ACSR
are provided. These 8-bit registers define functions
such as the selection of which analog channel is connected to the internal A/D converter, which pins are
used as analog inputs and which are used as normal
I/Os, the A/D clock source as well as controlling the start
function and monitoring the A/D converter end of conversion status.
· ADRH, ADRL Register
ADRH
ADRL
Bit
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
Name
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
¾
¾
¾
¾
R/W
R
R
R
R
R
R
R
R
R
R
R
R
¾
¾
¾
¾
POR
x
x
x
x
x
x
x
x
x
x
x
x
¾
¾
¾
¾
²x² unknown
unimplemented, read as ²0²
D11~D0: ADC conversion data
· ADCR Register
Bit
7
6
5
4
3
2
1
0
Name
START
EOCB
¾
PCR2
PCR1
PCR0
ACS1
ACS0
R/W
R/W
R
¾
R/W
R/W
R/W
R/W
R/W
POR
0
1
¾
0
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 ²1²
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
unimplemented, read as ²0²
Bit 4
PCR2: Define PA2 is A/D input or not
0: not A/D input
1: A/D input, AN2
Bit 3
PCR1: Define PA1 is A/D input or not
0: not A/D input
1: A/D input, AN1
Bit 2
PCR0: Define PA0 is A/D input or not
0: not A/D input
1: A/D input, AN0
Note that if the PCR2~PCR0 bits are all cleared to ²0², then the ADC module will enter power
down mode to reduce the power consumption.
Bit 2~0
ACS1, ACS0: Select A/D channel
00: AN0
01: AN1
10: AN2
11: Reserved
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November 29, 2011
HT48R005/HT46R005
· ACSR Register
Bit
7
6
5
4
3
2
1
0
Name
TEST
ADONB
¾
¾
¾
ADCS2
ADCS1
ADCS0
R/W
R/W
R/W
¾
¾
¾
R/W
R/W
R/W
POR
1
0
¾
¾
¾
0
0
0
Bit 7
TEST: for test mode use only
Bit 6
ADONB: ADC module power on/off control bit
0: ADC module power on
1: ADC module power off
Note: 1. it is recommended to set ADONB=1 before entering sleep for saving power.
2. ADONB=1 will power down the ADC module.
Bit 5~3
unimplemented, read as ²0²
Bit 2~0
ADCS2~ADCS0 : Select A/D converter clock source
000: fSYS/2
001: fSYS/8
010: fSYS/32
011: undefined, can¢t be used.
100: fSYS
101: fSYS/4
110: fSYS/16
111: undefined, can¢t be used.
These three bits are used to select the clock source for the A/D converter.
A/D Operation
when the A/D converter function is not being used. Note
that the ADC module ON or OFF will not be affected by
entering the HALT mode.
The START bit in the ADCR 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 ADCR 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.
PCRn
Bits
ADONB
Bit
ADC
On/Off
=0
X
X
Off
>0
X
0
On
>0
X
1
Off
Note: X: Don¢t care
A/D Converter On/Off Control
The EOCB bit in the ADCR 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 ADCR 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 ADCS2~ADCS0 bits in the
ACSR register.
Although the A/D clock source is determined by the system clock fSYS, and by bits ADCS2~ADCS0, there are
some limitations on the maximum A/D clock source
speed that can be selected. As the minimum value of permissible A/D clock period, tADCK, is 0.5ms, care must be
taken for system clock frequencies equal to or greater
than 4MHz. For example, if the system clock operates at
a frequency of 4MHz, the ADCS2~ADCS0 bits should
not be set to ²100². Doing so will give A/D clock periods
that are less than the minimum 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.
The ADC module power is managed by the ADONB in
the ACSR register and the PCRn bits in the ADCR register. The accompanying table illustrates the power control for the ADC module. As we can see from this table,
the ADC module can be disabled by setting the PCRn
bits to ²0² or the ADONB bit to ²0². It¢s recommended to
disable the ADC module to reduce power consumption
Rev. 1.00
HALT
Instruction
39
November 29, 2011
HT48R005/HT46R005
A/D Clock Period (tADCK)
ADCS2,
ADCS1,
ADCS0=000
(fSYS/2)
ADCS2,
ADCS1,
ADCS0=001
(fSYS/8)
ADCS2,
ADCS1,
ADCS0=010
(fSYS/32)
1MHz
2ms
8ms
2MHz
1ms
4ms
4MHz
500ns
8MHz
250ns*
12MHz
167ns*
fSYS
ADCS2,
ADCS1,
ADCS0=100
(fSYS)
ADCS2,
ADCS1,
ADCS0=101
(fSYS/4)
32ms
1ms
4ms
16ms
Undefined
16ms
500ns
2ms
8ms
Undefined
2ms
8ms
250ns*
1ms
4ms
Undefined
1ms
4ms
125ns*
500ns
2ms
Undefined
667ns
2.67ms
83ns*
333ns*
1ms
Undefined
ADCS2,
ADCS2,
ADCS1,
ADCS1,
ADCS0=110 ADCS0=011,
(fSYS/16)
111
A/D Clock Period Examples
A/D converter interrupt function is active. The master
interrupt control bit, EMI, and the A/D converter interrupt bit, EADI, must both be set high to do this.
A/D Input Pins
All of the A/D analog input pins are pin-shared with the
I/O pins on Port A as well as other functions. The PCR2~
PCR0 bits in the ADCR register, determine whether the
input pins are setup as A/D converter analog inputs or
whether they have other functions. If the PCR2~PCR0
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 PCR2~PCR0 bits enable an
A/D input, the status of the port control register will be
overridden.
· Step 6
The analog to digital conversion process can now be
initialised by setting the START bit in the ADCR register from low to high and then low again. Note that this
bit should have been originally cleared to zero.
· Step 7
To check when the analog to digital conversion process is complete, the EOCB bit in the ADCR 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.
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.
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 16tADCK where tADCK is equal to the
A/D clock period.
· Step 1
Select the required A/D conversion clock by correctly
programming bits ADCS2~ADCS0 in the ACSR register.
· Step 2
Select which pins are to be used as A/D inputs and
configure them by correctly programming the
PCR2~PCR0 bits in the ADCR register.
Programming Considerations
When programming, special attention must be given to
the PCR[2:0] bits in the register. If these bits are all
cleared to zero no external pins will be selected for use
as A/D input pins allowing the pins to be used as normal
I/O pins. When this happens the internal A/D circuitry
will be power down. Setting the ADONB bit high has the
ability to power down the internal A/D circuitry, which
may be an important consideration in power sensitive
applications.
· Step 3
Enable the A/D by clearing the ADONB bit in the
ACSR register to zero.
· Step 4
Select which channel is to be connected to the internal
A/D converter by correctly programming the
ACS1~ACS0 bits which are also contained in the
ADCR register.
· Step 5
If the interrupts are to be used, the interrupt control
registers must be correctly configured to ensure the
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HT48R005/HT46R005
A/D Transfer Function
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.
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 voltage, this gives a single bit analog input value of
VDD divided by 4096.
1 LSB= (VDD) ¸ 4096
A/D Programming Example
The A/D Converter input voltage value can be calculated using the following equation:
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
ADCR 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.
A/D input voltage =
A/D output digital value ´ (VDD) ¸ 4096
P C R 2 ~
P C R 0
0 0 0 B
x x x B - P C R [2 :0 ] is n o t e q u a l to " 0 "
A D O N B
tO
A D C m o d u le
O N
N 2 S T
o n
A /D
tA
s a m p lin g tim e
A /D
tA
D C S
o ff
s a m p lin g tim e
o n
D C S
S T A R T
E O C B
A C S 2 ~
A C S 0
x x x B
P o w e r-o n
R e s e t
0 1 0 B
0 0 0 B
0 0 1 B
S ta rt o f A /D
c o n v e r s io n
S ta rt o f A /D
c o n v e r s io n
S ta rt o f A /D
c o n v e r s io n
R e s e t A /D
c o n v e rte r
R e s e t A /D
c o n v e rte r
1 : D e fin e p o r t c o n fig u r a tio n
2 : S e le c t a n a lo g c h a n n e l
A /D
N o te :
R e s e t A /D
c o n v e rte r
E n d o f A /D
c o n v e r s io n
A /D c lo c k m u s t b e fs y s , fS
tA D C S = 4 tA D
tA D C = 1 6 tA D
Y S
E n d o f A /D
c o n v e r s io n
tA D C
c o n v e r s io n tim e
/2 , fS
Y S
/4 , fS
Y S
/8 , fS
A /D
/1 6 o r fS
Y S
Y S
tA D C
c o n v e r s io n tim e
/3 2
A/D Conversion Timing
1 .5 L S B
F F F H
F F E H
F F D H
A /D C o n v e r s io n
R e s u lt
0 .5 L S B
0 3 H
0 2 H
0 1 H
0
1
2
3
4 0 9 3 4 0 9 4
4 0 9 5 4 0 9 6
(
V D D
)
4 0 9 6
A n a lo g In p u t V o lta g e
Ideal A/D Transfer Function
Rev. 1.00
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HT48R005/HT46R005
Example: using an EOCB polling method to detect the end of conversion
clr ADI
; disable ADC interrupt
mov a,00000001B
mov ACSR,a
; select fSYS/8 as A/D clock and ADONB=0
mov a,00100000B
; setup ADCR register to configure Port as A/D inputs
mov ADCR,a
; and select AN0 to be connected to the A/D converter
:
:
Start_conversion:
clr START
set START
; reset A/D
clr START
; start A/D
Polling_EOC:
sz
EOCB
; poll the ADCR 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
Note: To power off ADC module, it is necessary to set ADONB as ²1².
Example: using the interrupt method to detect the end of conversion
clr ADI
; disable ADC interrupt
mov a,00000001B
mov ACSR,a
; select fSYS/8 as A/D clock and ADONB=0
mov a,00100000B
; setup ADCR register to configure Port as A/D inputs
mov ADCR,a
; and select AN0 to be connected to the A/D
:
:
Start_conversion:
clr START
set START
; reset A/D
clr START
; start A/D
clr ADF
; clear ADC interrupt request flag
set ADI
; enable ADC interrupt
set EMI
; enable global interrupt
:
:
:
; ADC interrupt service routine
ADC_:
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_ISR:
mov a,status_stack
mov STATUS,a
; restore STATUS from user defined memory
mov a,acc_stack
; restore ACC from user defined memory
clr ADF
; clear ADC interrupt flag
reti
Note: To power off ADC module, it is necessary to set ADONB as ²1².
Rev. 1.00
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HT48R005/HT46R005
Interrupts
Interrupts are an important part of any microcontroller
system. When an external event or an internal function
such as a Timer/Event Counter require microcontroller
attention, their corresponding interrupt will enforce a
temporary suspension of the main program allowing the
microcontroller to direct attention to their respective
needs.
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 statement
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 instruction, 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 devices contain a single external interrupt and multiple internal interrupts. The external interrupt is controlled by the action of the external interrupt pin, while
the internal interrupt is controlled by the Timer/Event
Counters overflow.
The various interrupt enable bits, together with their associated request flags, are shown in the following diagram with their order of priority.
Interrupt Register
Overall interrupt control, which means interrupt enabling
and request flag setting, is controlled by using the register, INTC0. By controlling the appropriate enable bits in
this registers each individual interrupt can be enabled or
disabled. Also when an interrupt occurs, the corresponding request flag will be set by the microcontroller.
The global enable flag if cleared to zero will disable all
interrupts.
Once an interrupt subroutine is serviced, all the other interrupts will be blocked, as the 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.
Interrupt Operation
A Timer/Event Counter overflow or an active edge on
the external interrupt pin will all generate an interrupt request by setting their corresponding request flag, if their
appropriate interrupt enable bit is set. When this happens, 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
A u to m a tic a lly C le a r e d b y IS R
M a n u a lly S e t o r C le a r e d b y S o ftw a r e
A u to m a tic a lly D is a b le d w h e n in te r r u p t
e v e n t is s e r v ic e d E n a b le d m a n u a lly o r
a u to m a tic a lly w ith R E T I in s tr u c tio n
P r io r ity
E x te rn a l In te rru p t
R e q u e s t F la g IN T F
E E I
E M I
T im e r /E v e n t C o u n te r
In te r r u p t R e q u e s t F la g T 0 F
E T 0 I
E M I
A /D C o n v e r s io n
In te r r u p t R e q u e s t F la g A D F
A D I
E M I
H ig h
In te rru p t
P o llin g
L o w
Note: HT48R005 hasn¢t ADC interrupt.
Interrupt Scheme
Rev. 1.00
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HT48R005/HT46R005
When an interrupt request is generated it takes 2 or 3 instruction cycle before the program jumps to the interrupt
vector. If the device is in the Sleep Mode and is woken
up by an interrupt request then it will take 3 cycles before the program jumps to the interrupt vector.
In cases where both external and internal interrupts are
enabled and where an external and internal interrupt occurs simultaneously, the external interrupt will always
have priority and will therefore be serviced first. Suitable
masking of the individual interrupts using the interrupt
registers can prevent simultaneous occurrences.
Main
Program
External Interrupt
Interrupt Request or
Interrupt Flag Set by Instruction
N
For an external interrupt to occur, the global interrupt enable bit, EMI, and external interrupt enable bit, INTE,
must first be set. An actual external interrupt will take
place when the external interrupt request flag, INTF, is
set, a situation that will occur when an edge transition
appears on the external INT line. The type of transition
that will trigger an external interrupt, whether high to low,
low to high or both is determined by the INTEG0 and
INTEG1 bits, which are bits 6 and 7 respectively, in the
CTRL1 control register. These two bits can also disable
the external interrupt function.
Enable Bit Set ?
Y
Main
Program
Automatically Disable Interrupt
Clear EMI & Request Flag
Wait for 2 ~ 3 Instruction Cycles
ISR Entry
RETI
(it will set EMI automatically)
Interrupt Flow
Interrupts, occurring in the interval between the rising
edges of two consecutive T2 pulses, will be serviced on
the latter of the two T2 pulses, if the corresponding interrupts are enabled. In case of simultaneous requests, the
following table shows the priority that is applied. These
can be masked by resetting the EMI bit.
· HT46R005
Priority Vector
External Interrupt
1
04H
Timer/Event Counter Overflow
2
08H
A/D Conversion Complete
4
10H
INTEG0
0
0
External interrupt disable
Edge Trigger Type
0
1
Rising edge Trigger
1
0
Falling edge Trigger
1
1
Both edge Trigger
The external interrupt pin is pin-shared with the I/O pin
and can only be configured as an external interrupt pin if
the corresponding external interrupt enable bit in the
INTC0 register has been set and the edge trigger type
has been selected using the CTRL1 register. 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 a transition
appears on the external interrupt pin, a subroutine call to
the external interrupt vector at location 04H, will take
place. When the interrupt is serviced, the external interrupt request flag, INTF, will be automatically reset and
the EMI bit will be automatically cleared to disable other
interrupts. Note that any pull-high resistor connections
on this pin will remain valid even if the pin is used as an
external interrupt input.
Interrupt Priority
Interrupt Source
INTEG1
· HT48R005
Interrupt Source
Priority Vector
External Interrupt
1
04H
Timer/Event Counter Overflow
2
08H
Rev. 1.00
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HT48R005/HT46R005
· INTC0 Register
¨
HT48R005
Bit
7
6
5
4
2
1
0
Name
¾
¾
T0F
INTF
¾
T0E
INTE
EMI
R/W
¾
¾
R/W
R/W
¾
R/W
R/W
R/W
POR
¾
¾
0
0
¾
0
0
0
Bit 7~6
unimplemented, read as ²0²
Bit 5
T0F: Timer/Event Counter interrupt request flag
0: inactive
1: active
Bit 4
INTF: External interrupt request flag
0: inactive
1: active
Bit 3
unimplemented, read as ²0²
Bit 2
T0E: Timer/Event Counter interrupt enable
0: disable
1: enable
Bit 1
INTE: External interrupt enable
0: disable
1: enable
Bit 0
EMI: Master interrupt global enable
0: disable
1: enable
¨
3
HT46R005
Bit
7
6
5
4
3
2
1
0
Name
¾
ADF
T0F
INTF
ADE
T0EG
INTE
EMI
R/W
¾
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
¾
0
0
0
0
0
0
0
Bit 7
unimplemented, read as ²0²
Bit 6
ADF: A/D Conversion interrupt request flag
0: inactive
1: active
Bit 5
T0F: Timer/Event Counter interrupt request flag
0: inactive
1: active
Bit 4
INTF: External interrupt request flag
0: inactive
1: active
Bit 3
ADE: A/D Conversion interrupt enable
0: disable
1: enable
Bit 2
T0EG: Timer/Event Counter interrupt enable
0: disable
1: enable
Bit 1
INTE: External interrupt enable
0: disable
1: enable
Bit 0
EMI: Master interrupt global enable
0: disable
1: enable
Rev. 1.00
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HT48R005/HT46R005
It is recommended that programs do not use the ²CALL
subroutine² instruction within the interrupt subroutine.
Interrupts often occur in an unpredictable manner or
need to be serviced immediately in some applications. If
only one stack is left and the interrupt is not well controlled, the original control sequence will be damaged
once a ²CALL subroutine² is executed in the interrupt
subroutine.
Timer/Event Counter Interrupt
For a Timer/Event Counter interrupt to occur, the global
interrupt enable bit, EMI, and the corresponding timer
interrupt enable bit, T0EG, must first be set. An actual
Timer/Event Counter interrupt will take place when the
Timer/Event Counter request flag, T0F, is set, a situation
that will occur when the relevant Timer/Event Counter
overflows. When the interrupt is enabled, the stack is
not full and a Timer/Event Counter overflow occurs, a
subroutine call to the relevant timer interrupt vector, will
take place. When the interrupt is serviced, the timer interrupt request flag, T0F, will be automatically reset and
the EMI bit will be automatically cleared to disable other
interrupts.
All of these interrupts have the capability of waking up
the processor when in the Sleep Mode.
Only the Program Counter is pushed onto the stack. If
the contents of the register or status register are altered
by the interrupt service program, which may corrupt the
desired control sequence, then the contents should be
saved in advance.
Programming Considerations
By disabling the 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
a software instruction.
Configuration Options
Configuration options refer to certain options within the MCU that are programmed into the OTP Program Memory 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 by the application software. All options must be defined for proper
system function, the details of which are shown in the table.
No.
Options
1
Watchdog Timer: enable or disable
2
Watchdog Timer clock source: LIRC or fSYS/4
3
CLRWDT instructions: 1 or 2 instructions
4
System oscillator configuration: HXT, HIRC, ERC
5
LVR function: enable or disable
6
LVR voltage: 2.1V, 3.15V or 4.2V
7
RES or PA7 pin function
8
Internal RC: 4MHz, 8MHz or 12MHz
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Application Circuits
V
D D
0 .0 1 m F
0 .1 m F
V D D
R e s e t
C ir c u it
1 0 k W ~
1 0 0 k W
1 N 4 1 4 8
0 .1 ~ 1 m F
R E S /P A 7
3 0 0 W
V S S
P A 0 /B Z /A N 0
P A 1 /B Z /A N 1
P A 2 /T M R /IN T /A N 2
P A 6 /O S C 1
O S C
C ir c u it
P A 5 /O S C 2
S e e O s c illa to r
S e c tio n
N o te : " * " T h e c o m p o n e n ts in " R e s e t C ir c u it"
T h e H T 4 8 R 0 0 5 h a s n 't t h e A N 0 ~ A N 2 p in s .
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Instruction Set
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.
Introduction
C e n t ra l t o t he s uc c es s f ul oper a t i on o f a n y
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.
Logical and Rotate Operations
For easier understanding of the various instruction
codes, they have been subdivided into several functional groupings.
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.
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 0.5ms and branch or call instructions would be implemented within 1ms. 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 ²CLR PCL² or ²MOV PCL, A². 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.
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.
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
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Bit Operations
Other 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 ²SET
[m].i² or ²CLR [m].i² 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.
In addition to the above functional instructions, a range
of other instructions also exist such as the ²HALT² 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.
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 Read Operations
Table conventions:
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.
Mnemonic
x: Bits immediate data
m: Data Memory address
A: Accumulator
i: 0~7 number of bits
addr: Program memory address
Description
Cycles
Flag Affected
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
1
1
1
1Note
1Note
1Note
1
1
1
1Note
1
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
1
1Note
1
1Note
Z
Z
Z
Z
Arithmetic
ADD A,[m]
ADDM A,[m]
ADD A,x
ADC A,[m]
ADCM A,[m]
SUB A,x
SUB A,[m]
SUBM A,[m]
SBC A,[m]
SBCM A,[m]
DAA [m]
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
Logic Operation
AND A,[m]
OR A,[m]
XOR A,[m]
ANDM A,[m]
ORM A,[m]
XORM A,[m]
AND A,x
OR A,x
XOR A,x
CPL [m]
CPLA [m]
Logical AND Data Memory to ACC
Logical OR Data Memory to ACC
Logical XOR Data Memory to ACC
Logical AND ACC to Data Memory
Logical OR ACC to Data Memory
Logical XOR ACC to Data Memory
Logical AND immediate Data to ACC
Logical OR immediate Data to ACC
Logical XOR immediate Data to ACC
Complement Data Memory
Complement Data Memory with result in ACC
Increment & Decrement
INCA [m]
INC [m]
DECA [m]
DEC [m]
Rev. 1.00
Increment Data Memory with result in ACC
Increment Data Memory
Decrement Data Memory with result in ACC
Decrement Data Memory
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Mnemonic
Description
Cycles
Flag Affected
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
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
Rotate
RRA [m]
RR [m]
RRCA [m]
RRC [m]
RLA [m]
RL [m]
RLCA [m]
RLC [m]
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 ²CLR WDT1² and ²CLR WDT2² instructions the TO and PDF flags may be affected by
the execution status. The TO and PDF flags are cleared after both ²CLR WDT1² and
²CLR WDT2² instructions are consecutively executed. Otherwise the TO and PDF flags
remain unchanged.
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Instruction Definition
ADC A,[m]
Add Data Memory to ACC with Carry
Description
The contents of the specified Data Memory, Accumulator and the carry flag are added. The
result is stored in the Accumulator.
Operation
ACC ¬ ACC + [m] + C
Affected flag(s)
OV, Z, AC, C
ADCM A,[m]
Add ACC to Data Memory with Carry
Description
The contents of the specified Data Memory, Accumulator and the carry flag are added. The
result is stored in the specified Data Memory.
Operation
[m] ¬ ACC + [m] + C
Affected flag(s)
OV, Z, AC, C
ADD A,[m]
Add Data Memory to ACC
Description
The contents of the specified Data Memory and the Accumulator are added. The result is
stored in the Accumulator.
Operation
ACC ¬ ACC + [m]
Affected flag(s)
OV, Z, AC, C
ADD A,x
Add immediate data to ACC
Description
The contents of the Accumulator and the specified immediate data are added. The result is
stored in the Accumulator.
Operation
ACC ¬ ACC + x
Affected flag(s)
OV, Z, AC, C
ADDM A,[m]
Add ACC to Data Memory
Description
The contents of the specified Data Memory and the Accumulator are added. The result is
stored in the specified Data Memory.
Operation
[m] ¬ ACC + [m]
Affected flag(s)
OV, Z, AC, C
AND A,[m]
Logical AND Data Memory to ACC
Description
Data in the Accumulator and the specified Data Memory perform a bitwise logical AND operation. The result is stored in the Accumulator.
Operation
ACC ¬ ACC ²AND² [m]
Affected flag(s)
Z
AND A,x
Logical AND immediate data to ACC
Description
Data in the Accumulator and the specified immediate data perform a bitwise logical AND
operation. The result is stored in the Accumulator.
Operation
ACC ¬ ACC ²AND² x
Affected flag(s)
Z
ANDM A,[m]
Logical AND ACC to Data Memory
Description
Data in the specified Data Memory and the Accumulator perform a bitwise logical AND operation. The result is stored in the Data Memory.
Operation
[m] ¬ ACC ²AND² [m]
Affected flag(s)
Z
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CALL addr
Subroutine call
Description
Unconditionally calls a subroutine at the specified address. The Program Counter then increments by 1 to obtain the address of the next instruction which is then pushed onto the
stack. The specified address is then loaded and the program continues execution from this
new address. As this instruction requires an additional operation, it is a two cycle instruction.
Operation
Stack ¬ Program Counter + 1
Program Counter ¬ addr
Affected flag(s)
None
CLR [m]
Clear Data Memory
Description
Each bit of the specified Data Memory is cleared to 0.
Operation
[m] ¬ 00H
Affected flag(s)
None
CLR [m].i
Clear bit of Data Memory
Description
Bit i of the specified Data Memory is cleared to 0.
Operation
[m].i ¬ 0
Affected flag(s)
None
CLR WDT
Clear Watchdog Timer
Description
The TO, PDF flags and the WDT are all cleared.
Operation
WDT cleared
TO ¬ 0
PDF ¬ 0
Affected flag(s)
TO, PDF
CLR WDT1
Pre-clear Watchdog Timer
Description
The TO, PDF flags and the WDT are all cleared. Note that this instruction works in conjunction with CLR WDT2 and must be executed alternately with CLR WDT2 to have effect. Repetitively executing this instruction without alternately executing CLR WDT2 will have no
effect.
Operation
WDT cleared
TO ¬ 0
PDF ¬ 0
Affected flag(s)
TO, PDF
CLR WDT2
Pre-clear Watchdog Timer
Description
The TO, PDF flags and the WDT are all cleared. Note that this instruction works in conjunction with CLR WDT1 and must be executed alternately with CLR WDT1 to have effect. Repetitively executing this instruction without alternately executing CLR WDT1 will have no
effect.
Operation
WDT cleared
TO ¬ 0
PDF ¬ 0
Affected flag(s)
TO, PDF
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CPL [m]
Complement Data Memory
Description
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.
Operation
[m] ¬ [m]
Affected flag(s)
Z
CPLA [m]
Complement Data Memory with result in ACC
Description
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.
Operation
ACC ¬ [m]
Affected flag(s)
Z
DAA [m]
Decimal-Adjust ACC for addition with result in Data Memory
Description
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.
Operation
[m] ¬ ACC + 00H or
[m] ¬ ACC + 06H or
[m] ¬ ACC + 60H or
[m] ¬ ACC + 66H
Affected flag(s)
C
DEC [m]
Decrement Data Memory
Description
Data in the specified Data Memory is decremented by 1.
Operation
[m] ¬ [m] - 1
Affected flag(s)
Z
DECA [m]
Decrement Data Memory with result in ACC
Description
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.
Operation
ACC ¬ [m] - 1
Affected flag(s)
Z
HALT
Enter power down mode
Description
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.
Operation
TO ¬ 0
PDF ¬ 1
Affected flag(s)
TO, PDF
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INC [m]
Increment Data Memory
Description
Data in the specified Data Memory is incremented by 1.
Operation
[m] ¬ [m] + 1
Affected flag(s)
Z
INCA [m]
Increment Data Memory with result in ACC
Description
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.
Operation
ACC ¬ [m] + 1
Affected flag(s)
Z
JMP addr
Jump unconditionally
Description
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.
Operation
Program Counter ¬ addr
Affected flag(s)
None
MOV A,[m]
Move Data Memory to ACC
Description
The contents of the specified Data Memory are copied to the Accumulator.
Operation
ACC ¬ [m]
Affected flag(s)
None
MOV A,x
Move immediate data to ACC
Description
The immediate data specified is loaded into the Accumulator.
Operation
ACC ¬ x
Affected flag(s)
None
MOV [m],A
Move ACC to Data Memory
Description
The contents of the Accumulator are copied to the specified Data Memory.
Operation
[m] ¬ ACC
Affected flag(s)
None
NOP
No operation
Description
No operation is performed. Execution continues with the next instruction.
Operation
No operation
Affected flag(s)
None
OR A,[m]
Logical OR Data Memory to ACC
Description
Data in the Accumulator and the specified Data Memory perform a bitwise logical OR operation. The result is stored in the Accumulator.
Operation
ACC ¬ ACC ²OR² [m]
Affected flag(s)
Z
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OR A,x
Logical OR immediate data to ACC
Description
Data in the Accumulator and the specified immediate data perform a bitwise logical OR operation. The result is stored in the Accumulator.
Operation
ACC ¬ ACC ²OR² x
Affected flag(s)
Z
ORM A,[m]
Logical OR ACC to Data Memory
Description
Data in the specified Data Memory and the Accumulator perform a bitwise logical OR operation. The result is stored in the Data Memory.
Operation
[m] ¬ ACC ²OR² [m]
Affected flag(s)
Z
RET
Return from subroutine
Description
The Program Counter is restored from the stack. Program execution continues at the restored address.
Operation
Program Counter ¬ Stack
Affected flag(s)
None
RET A,x
Return from subroutine and load immediate data to ACC
Description
The Program Counter is restored from the stack and the Accumulator loaded with the
specified immediate data. Program execution continues at the restored address.
Operation
Program Counter ¬ Stack
ACC ¬ x
Affected flag(s)
None
RETI
Return from interrupt
Description
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.
Operation
Program Counter ¬ Stack
EMI ¬ 1
Affected flag(s)
None
RL [m]
Rotate Data Memory left
Description
The contents of the specified Data Memory are rotated left by 1 bit with bit 7 rotated into bit
0.
Operation
[m].(i+1) ¬ [m].i; (i = 0~6)
[m].0 ¬ [m].7
Affected flag(s)
None
RLA [m]
Rotate Data Memory left with result in ACC
Description
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.
Operation
ACC.(i+1) ¬ [m].i; (i = 0~6)
ACC.0 ¬ [m].7
Affected flag(s)
None
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RLC [m]
Rotate Data Memory left through Carry
Description
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.
Operation
[m].(i+1) ¬ [m].i; (i = 0~6)
[m].0 ¬ C
C ¬ [m].7
Affected flag(s)
C
RLCA [m]
Rotate Data Memory left through Carry with result in ACC
Description
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.
Operation
ACC.(i+1) ¬ [m].i; (i = 0~6)
ACC.0 ¬ C
C ¬ [m].7
Affected flag(s)
C
RR [m]
Rotate Data Memory right
Description
The contents of the specified Data Memory are rotated right by 1 bit with bit 0 rotated into
bit 7.
Operation
[m].i ¬ [m].(i+1); (i = 0~6)
[m].7 ¬ [m].0
Affected flag(s)
None
RRA [m]
Rotate Data Memory right with result in ACC
Description
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.
Operation
ACC.i ¬ [m].(i+1); (i = 0~6)
ACC.7 ¬ [m].0
Affected flag(s)
None
RRC [m]
Rotate Data Memory right through Carry
Description
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.
Operation
[m].i ¬ [m].(i+1); (i = 0~6)
[m].7 ¬ C
C ¬ [m].0
Affected flag(s)
C
RRCA [m]
Rotate Data Memory right through Carry with result in ACC
Description
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.
Operation
ACC.i ¬ [m].(i+1); (i = 0~6)
ACC.7 ¬ C
C ¬ [m].0
Affected flag(s)
C
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SBC A,[m]
Subtract Data Memory from ACC with Carry
Description
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.
Operation
ACC ¬ ACC - [m] - C
Affected flag(s)
OV, Z, AC, C
SBCM A,[m]
Subtract Data Memory from ACC with Carry and result in Data Memory
Description
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.
Operation
[m] ¬ ACC - [m] - C
Affected flag(s)
OV, Z, AC, C
SDZ [m]
Skip if decrement Data Memory is 0
Description
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.
Operation
[m] ¬ [m] - 1
Skip if [m] = 0
Affected flag(s)
None
SDZA [m]
Skip if decrement Data Memory is zero with result in ACC
Description
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.
Operation
ACC ¬ [m] - 1
Skip if ACC = 0
Affected flag(s)
None
SET [m]
Set Data Memory
Description
Each bit of the specified Data Memory is set to 1.
Operation
[m] ¬ FFH
Affected flag(s)
None
SET [m].i
Set bit of Data Memory
Description
Bit i of the specified Data Memory is set to 1.
Operation
[m].i ¬ 1
Affected flag(s)
None
Rev. 1.00
57
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HT48R005/HT46R005
SIZ [m]
Skip if increment Data Memory is 0
Description
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.
Operation
[m] ¬ [m] + 1
Skip if [m] = 0
Affected flag(s)
None
SIZA [m]
Skip if increment Data Memory is zero with result in ACC
Description
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.
Operation
ACC ¬ [m] + 1
Skip if ACC = 0
Affected flag(s)
None
SNZ [m].i
Skip if bit i of Data Memory is not 0
Description
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.
Operation
Skip if [m].i ¹ 0
Affected flag(s)
None
SUB A,[m]
Subtract Data Memory from ACC
Description
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.
Operation
ACC ¬ ACC - [m]
Affected flag(s)
OV, Z, AC, C
SUBM A,[m]
Subtract Data Memory from ACC with result in Data Memory
Description
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.
Operation
[m] ¬ ACC - [m]
Affected flag(s)
OV, Z, AC, C
SUB A,x
Subtract immediate data from ACC
Description
The immediate data specified by the code is subtracted from the contents of the Accumulator. The result is stored in the Accumulator. Note that if the result of subtraction is negative, the C flag will be cleared to 0, otherwise if the result is positive or zero, the C flag will
be set to 1.
Operation
ACC ¬ ACC - x
Affected flag(s)
OV, Z, AC, C
Rev. 1.00
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HT48R005/HT46R005
SWAP [m]
Swap nibbles of Data Memory
Description
The low-order and high-order nibbles of the specified Data Memory are interchanged.
Operation
[m].3~[m].0 « [m].7 ~ [m].4
Affected flag(s)
None
SWAPA [m]
Swap nibbles of Data Memory with result in ACC
Description
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.
Operation
ACC.3 ~ ACC.0 ¬ [m].7 ~ [m].4
ACC.7 ~ ACC.4 ¬ [m].3 ~ [m].0
Affected flag(s)
None
SZ [m]
Skip if Data Memory is 0
Description
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.
Operation
Skip if [m] = 0
Affected flag(s)
None
SZA [m]
Skip if Data Memory is 0 with data movement to ACC
Description
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.
Operation
ACC ¬ [m]
Skip if [m] = 0
Affected flag(s)
None
SZ [m].i
Skip if bit i of Data Memory is 0
Description
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.
Operation
Skip if [m].i = 0
Affected flag(s)
None
TABRDC [m]
Read table (current page) to TBLH and Data Memory
Description
The low byte of the program code (current page) addressed by the table pointer (TBLP) is
moved to the specified Data Memory and the high byte moved to TBLH.
Operation
[m] ¬ program code (low byte)
TBLH ¬ program code (high byte)
Affected flag(s)
None
TABRDL [m]
Read table (last page) to TBLH and Data Memory
Description
The low byte of the program code (last page) addressed by the table pointer (TBLP) is
moved to the specified Data Memory and the high byte moved to TBLH.
Operation
[m] ¬ program code (low byte)
TBLH ¬ program code (high byte)
Affected flag(s)
None
Rev. 1.00
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HT48R005/HT46R005
XOR A,[m]
Logical XOR Data Memory to ACC
Description
Data in the Accumulator and the specified Data Memory perform a bitwise logical XOR operation. The result is stored in the Accumulator.
Operation
ACC ¬ ACC ²XOR² [m]
Affected flag(s)
Z
XORM A,[m]
Logical XOR ACC to Data Memory
Description
Data in the specified Data Memory and the Accumulator perform a bitwise logical XOR operation. The result is stored in the Data Memory.
Operation
[m] ¬ ACC ²XOR² [m]
Affected flag(s)
Z
XOR A,x
Logical XOR immediate data to ACC
Description
Data in the Accumulator and the specified immediate data perform a bitwise logical XOR
operation. The result is stored in the Accumulator.
Operation
ACC ¬ ACC ²XOR² x
Affected flag(s)
Z
Rev. 1.00
60
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HT48R005/HT46R005
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 (http://www.holtek.com.tw/english/literature/package.pdf) for
the latest version of the package information.
10-pin MSOP Outline Dimensions
1 0
6
E 1
1
5
E
D
L
A 2
A
e
R
B
0 .1 0
C
q
A 1
L 1
(4 C O R N E R S )
Symbol
Nom.
Max.
A
¾
¾
0.043
A1
0.000
¾
0.006
A2
0.030
0.033
0.037
B
0.007
¾
0.011
C
¾
¾
0.010
D
¾
0.018
¾
E
¾
0.193
¾
E1
¾
0.118
¾
e
¾
0.020
¾
L
0.016
0.024
0.031
L1
¾
0.037
¾
q
0°
¾
8°
Symbol
Rev. 1.00
Dimensions in inch
Min.
Dimensions in mm
Min.
Nom.
Max.
A
¾
¾
1.10
A1
0.00
¾
0.15
A2
0.75
0.85
0.95
B
0.17
¾
0.27
C
¾
¾
0.25
D
¾
3.00
¾
E
¾
4.90
¾
E1
¾
3.00
¾
e
¾
0.50
¾
L
0.40
0.60
0.80
L1
¾
0.95
¾
q
0°
¾
8°
61
November 29, 2011
HT48R005/HT46R005
Holtek Semiconductor Inc. (Headquarters)
No.3, Creation Rd. II, Science Park, Hsinchu, Taiwan
Tel: 886-3-563-1999
Fax: 886-3-563-1189
http://www.holtek.com.tw
Holtek Semiconductor Inc. (Taipei Sales Office)
4F-2, No. 3-2, YuanQu St., Nankang Software Park, Taipei 115, Taiwan
Tel: 886-2-2655-7070
Fax: 886-2-2655-7373
Fax: 886-2-2655-7383 (International sales hotline)
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5F, Unit A, Productivity Building, No.5 Gaoxin M 2nd Road, Nanshan District, Shenzhen, China 518057
Tel: 86-755-8616-9908, 86-755-8616-9308
Fax: 86-755-8616-9722
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46729 Fremont Blvd., Fremont, CA 94538
Tel: 1-510-252-9880
Fax: 1-510-252-9885
http://www.holtek.com
Copyright Ó 2011 by HOLTEK SEMICONDUCTOR INC.
The information appearing in this Data Sheet is believed to be accurate at the time of publication. However, Holtek assumes no responsibility arising from the use of the specifications described. The applications mentioned herein are used
solely for the purpose of illustration and Holtek makes no warranty or representation that such applications will be suitable
without further modification, nor recommends the use of its products for application that may present a risk to human life
due to malfunction or otherwise. Holtek¢s products are not authorized for use as critical components in life support devices
or systems. Holtek reserves the right to alter its products without prior notification. For the most up-to-date information,
please visit our web site at http://www.holtek.com.tw.
Rev. 1.00
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November 29, 2011