HOLTEK HT48CA3

HT48RA3/HT48CA3
Remote Type 8-Bit MCU
Technical Document
· Tools Information
· FAQs
· Application Note
-
HA0016E
HA0018E
HA0041E
HA0075E
HA0076E
HA0082E
Writing and Reading to the HT24 EEPROM with the HT48 MCU Series
Controlling the HT1621 LCD Controller with the HT48 MCU Series
Using the HT48CA0 to Generate the HT6221 Output Signals
MCU Reset and Oscillator Circuits Application Note
HT48RAx/HT48CAx Software Application Note
HT48xA0-1 and HT48xA0-2 Power-on Reset Timing
Features
· Operating voltage: 2.0V~5.5V
· PFD supported
· 23 bidirectional I/O lines (max.)
· HALT function and wake-up feature reduce power
consumption
· 1 interrupt input shared with an I/O line
· 8-level subroutine nesting
· 8-bit programmable timer/event counter with overflow
· Up to 1ms instruction cycle with 4MHz system clock at
interrupt and 8-stage prescaler (TMR0)
· 16-bit programmable timer/event counter and over-
VDD=3V
· Bit manipulation instruction
flow interrupts (TMR1)
· On-chip crystal and RC oscillator
· 16-bit table read instruction
· Watchdog Timer
· 63 powerful instructions
· 24K´16 program memory ROM (8K´16 bits´3
· All instructions in one or two machine cycles
banks)
· Low voltage reset function
· 224´8 data memory RAM
· 28-pin SOP/SSOP (209mil) package
General Description
The advantages of low power consumption, I/O flexibility, timer functions, oscillator options, watchdog timer,
programmable frequency divider, HALT and wake-up
functions, as well as low cost, enhance the versatility of
these devices to suit a wide range of application possibilities such as industrial control, consumer products,
subsystem controllers, and particularly suitable for use
in products such as universal remote controller (URC).
The HT48RA3/HT48CA3 are 8-bit high performance,
RISC architecture microcontroller devices specifically
designed for multiple I/O control product applications.
The data ROM can be used to store remote control
codes. The mask version HT48CA3 is fully pin and functionally compatible with the OTP version HT48RA3 device.
Rev. 1.30
1
October 12, 2007
HT48RA3/HT48CA3
Block Diagram
T M R 1 C
IN T /P F 0
M
T M R 1
fS
U
X
In te rru p t
C ir c u it
P ro g ra m
R O M
P ro g ra m
C o u n te r
S T A C K
IN T C
/4
T M R 1
M
T M R 0
Y S
U
P r e s c a le r
fS
Y S
T M R 0
X
T M R 0 C
B P
E N /D IS
In s tr u c tio n
R e g is te r
M
M P
U
W D T S
X
D A T A
M e m o ry
W D T P r e s c a le r
W D T
M
U
fS
Y S
/4
X
W D T O S C
P A C
M U X
In s tr u c tio n
D e c o d e r
A L U
T im in g
G e n e ra to r
O S C 1
P A 0 ~ P A 7
P F D
S T A T U S
P B C
S h ifte r
P O R T B
P B
P C C
O S C 2
P O R T A
P A
P O R T C
P C
A C C
R E S
V D D
V S S
P F C
P O R T F
P F
P B 0 ~ P B 7
P C 0 ~ P C 5
P F 0
Pin Assignment
P B 5
1
2 8
P B 6
P B 4
2
2 7
P B 7
P A 3
3
2 6
P A 4
P A 2
4
2 5
P A 5
P A 1
5
2 4
P A 6
P A 0
6
2 3
P A 7
P B 3
7
2 2
O S C 2
P B 2
8
2 1
O S C 1
P B 1
9
2 0
V D D
P B 0 /P F D
1 0
1 9
R E S
P C 5 /T M R 1
V S S
1 1
1 8
P F 0 /IN T
1 2
1 7
P C 4
P C 0 /T M R 0
1 3
1 6
P C 3
P C 1
1 4
1 5
P C 2
H T 4 8 R A 3 /H T 4 8 C A 3
2 8 S O P -A /S S O P -A
Rev. 1.30
2
October 12, 2007
HT48RA3/HT48CA3
Pin Description
Pin Name
RES
PA0~PA7
I/O
ROM Code
Option
I
¾
I/O
Wake-up*
Pull-high***
Bidirectional 8-bit input/output port. Each bit can be configured as a
wake-up input by an option. Software instructions determine the
CMOS output or Schmitt trigger input with/without pull-high resistor. The
pull-high resistor of each input/output line is also optional.
Bidirectional 8-bit input/output port. Software instructions determine
the CMOS output or Schmitt trigger input with/without pull-high resistor. The pull-high resistor of each input/output line is also optional. The
output mode of PB0 can be used as an internal PFD signal output and
it can be used as a various frequency carrier signal.
PB0/PFD
PB1~PB7
I/O
Pull-high**
PB0 or PFD
VSS
¾
¾
PC0/TMR0
PC1~PC4
PC5/TMR1
I/O
Schmitt trigger reset input, active low.
Negative power supply, ground
Pull-high*
Bidirectional 6-bit input/output port. Software instructions determine
the CMOS output or Schmitt trigger input with/without pull-high resistor. The pull-high resistor of each input/output line is also optional. PC0
and PC5 are pin shared with TMR0 and TMR1 function pins.
Bidirectional 1-bit input/output port. Software instructions determine
the CMOS output or Schmitt trigger input with/without pull-high resistor. The pull-high resistor of this input/output line is also optional. PF0
is pin shared with the INT function pin.
PF0/INT
I/O
Pull-high*
VDD
¾
¾
OSC1
OSC2
I
O
Crystal
or RC
Note:
Description
Positive power supply
OSC1, OSC2 are connected to an RC network or Crystal (determined
by hardware option) for the internal system clock. In the case of RC operation, OSC2 is the output terminal for 1/4 system clock.
²*² Bit option
²**² Nibble option
²***² Byte option
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
Operating Temperature...........................-40°C to 85°C
IOL Total ..............................................................150mA
IOH Total ............................................................-100mA
Total Power Dissipation .....................................500mW
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. 1.30
3
October 12, 2007
HT48RA3/HT48CA3
D.C. Characteristics
Symbol
Parameter
VDD
Operating Voltage
IDD1
Operating Current
Ta=25°C
Test Conditions
VDD
Conditions
¾
¾
3V
No load, fSYS=4MHz
5V
IDD2
Operating Current
(Crystal OSC, RC OSC)
ISTB1
Standby Current (WDT Enabled
and WDT RC OSC On)
ISTB2
5V
No load, fSYS=8MHz
3V
No load, system HALT
5V
3V
Standby Current (WDT Disabled)
No load, system HALT
5V
Min.
Typ.
Max.
Unit
2.0
¾
5.5
V
¾
0.6
1.5
mA
¾
2
4
mA
¾
4
8
mA
¾
1.1
5
mA
¾
4
10
mA
¾
0.1
1
mA
¾
0.2
2
mA
VIL1
Input Low Voltage for I/O Ports
¾
¾
0
¾
0.3VDD
V
VIH1
Input High Voltage for I/O Ports
¾
¾
0.7VDD
¾
VDD
V
VIL2
Input Low Voltage (RES)
¾
¾
0
¾
0.4VDD
V
VIH2
Input High Voltage (RES)
¾
¾
0.9VDD
¾
VDD
V
VLVR
¾
LVR=2.0V
1.8
1.9
2.0
V
Low Voltage Reset
LVR=3.0V
2.7
3.0
3.3
V
IOL
4
8
¾
mA
I/O Port Sink Current
10
20
¾
mA
-2
-4
¾
mA
-5
-10
¾
mA
20
60
100
kW
10
30
50
kW
3V
VOL=0.1VDD
5V
IOH
3V
I/O Port Source Current
VOH=0.9VDD
5V
RPH
3V
¾
Pull-high Resistance
5V
Rev. 1.30
4
October 12, 2007
HT48RA3/HT48CA3
A.C. Characteristics
Symbol
fSYS1
fSYS2
fTIMER
tWDTOSC
Parameter
System Clock
(Crystal OSC)
System Clock
(RC OSC)
Timer I/P Frequency
(TMR0/TMR1)
Ta=25°C
Test Conditions
Conditions
VDD
Min.
Typ.
Max.
Unit
¾
2.0V~5.5V
400
¾
4000
kHz
¾
3.3V~5.5V
400
¾
8000
kHz
¾
2.0V~5.5V
400
¾
4000
kHz
¾
3.3V~5.5V
400
¾
8000
kHz
0
¾
4000
kHz
0
¾
8000
kHz
45
90
180
ms
32
65
130
ms
11
23
46
ms
17
33
ms
3V
50% duty
5V
3V
¾
Watchdog Oscillator Period
5V
tWDT1
Watchdog Time-out Period
(WDT OSC)
3V
5V
8
tWDT2
Watchdog Time-out Period (fSYS/4)
¾
Without WDT prescaler
¾
1024
¾
tSYS
tRES
External Reset Low Pulse Width
¾
¾
1
¾
¾
ms
tSST
System Start-up Timer Period
¾
¾
1024
¾
tSYS
tLVR
Low Voltage Width to Reset
¾
¾
1
¾
¾
ms
tINT
Interrupt Pulse Width
¾
¾
1
¾
¾
ms
tACC
Data ROM Access Time
¾
¾
1
¾
¾
ms
Without WDT prescaler
Power-up reset or
wake-up from HALT
Note: tSYS=1/(fSYS)
Rev. 1.30
5
October 12, 2007
HT48RA3/HT48CA3
Functional Description
incremented by one. The program counter then points to
the memory word containing the next instruction code.
Execution Flow
The system clock for the MCU is derived from either a
crystal or an RC oscillator. The system clock is internally
divided into four non-overlapping clocks. One instruction cycle consists of four system clock cycles.
When executing a jump instruction, conditional skip execution, loading register, subroutine call or return from
subroutine, initial reset, internal interrupt, external interrupt or return from interrupts, the PC manipulates the
program transfer by loading the address corresponding
to each instruction.
Instruction fetching and execution are pipelined in such
a way that a fetch takes an instruction cycle while decoding and execution takes the next instruction cycle.
However, the pipelining scheme causes each instruction to effectively execute in a cycle. If an instruction
changes the program counter, two cycles are required to
complete the instruction.
The conditional skip is activated by instructions. Once
the condition is met, the next instruction, fetched during
the current instruction execution, is discarded and a
dummy cycle replaces it to get the proper instruction.
Otherwise proceed to the next instruction.
Program Counter - PC
The lower byte of the program counter (PCL) is a readable and writeable register (06H). Moving data into the
PCL performs a short jump. The destination will be
within the current program ROM page.
The program counter (PC) controls the sequence in
which the instructions stored in the program ROM are
executed and its contents specify a full range of program memory.
When a control transfer takes place, an additional
dummy cycle is required.
After accessing a program memory word to fetch an instruction code, the contents of the program counter are
S y s te m
C lo c k
T 1
T 2
T 3
T 4
T 1
T 2
T 3
T 4
T 1
T 2
T 3
T 4
O S C 2 ( R C o n ly )
P C
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 )
Execution Flow
Mode
Program Counter
*14~*8
*7
*6
*5
*4
*3
*2
*1
*0
Initial Reset
0000000
0
0
0
0
0
0
0
0
External Interrupt
0000000
0
0
0
0
0
1
0
0
Timer/Event Counter 0 Overflow
0000000
0
0
0
0
1
0
0
0
Timer/Event Counter 1 Overflow
0000000
0
0
0
0
1
1
0
0
Skip
*14~*13, (*12~*0+2): (within current bank)
Loading PCL
Jump, Call Branch
Return (RET, RETI)
*14~*8
@7
@6
@5
@4
@3
@2
@1
@0
BP(1~0), #12~#8
#7
#6
#5
#4
#3
#2
#1
#0
S14~S8
S7
S6
S5
S4
S3
S2
S1
S0
Program Counter
Note: *14~*0: Program counter bits
S14~S0: Stack register bits
#14~#0: Instruction code bits
@[email protected]: PCL bits
1 bank: 8K words
Rev. 1.30
6
October 12, 2007
HT48RA3/HT48CA3
Program Memory - ROM
0 0 0 H
The program memory is used to store the program instructions which are to be executed. It also contains
data, table, and interrupt entries, and is organized into
8192´16 bits´3 banks, addressed by the program counter and table pointer.
0 0 4 H
E x te r n a l In te r r u p t S u b r o u tin e
0 0 8 H
Certain locations in the program memory are reserved
for special usage:
T im e r /E v e n t C o u n te r
In te r r u p t S u b r o u tin e
P ro g ra m
M e m o ry
n 0 0 H
L o o k - u p T a b le ( 2 5 6 w o r d s )
n F F H
· Location 000H
This area is reserved for program initialization. After
chip reset, the program always begins execution at location 000H.
L o o k - u p T a b le ( 2 5 6 w o r d s )
5 F F F H
· Location 004H
1 6 b its
This area is reserved for the external interrupt service
program. If the INT input pin is activated, the interrupt
is enabled and the stack is not full, the program begins
execution at location 004H.
N o te : n ra n g e s fro m
0 to 5 F
Program Memory
· Location 008H
about. Given this, using the table read instruction in
the main routine and the ISR simultaneously should
be avoided. However, if the table read instruction has
to be applied in both main routine and the ISR, the interrupt(s) is supposed to be disabled prior to the table
read instruction. It (They) will not be enabled until the
TBLH in the main routine has been backup. All table
related instructions require 2 cycles to complete the
operation.
This area is reserved for the Timer/Event Counter 0 interrupt service program. If a timer interrupt results from a
Timer/Event Counter 0 overflow, and if the interrupt is
enabled and the stack is not full, the program begins execution at location 008H .
· Location 00CH
This location is reserved for the Timer/Event Counter
1 interrupt service program. If a timer interrupt results
from a Timer/Event Counter 1 overflow, and the interrupt is enabled and the stack is not full, the program
begins execution at location 00CH.
Stack Register - STACK
This is a special part of the memory which is used to
save the contents of the program counter (PC) only. The
stack is organized into 8 levels and is neither part of the
data nor part of the program space, and is neither readable nor writeable. The activated level is indexed by the
stack pointer (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 chip reset, the SP will point to the top of the
stack.
· Table location
Any location in the program memory can be used as
look-up tables. The instructions ²TABRDC [m]² (page
specified by TBHP) and ²TABRDL [m]² (the last page)
transfer the contents of the lower-order byte to the
specified data memory, and the higher-order byte to
TBLH (08H). The higher-order byte table pointer
TBHP (1FH) and lower-order byte table pointer TBLP
(07H) are read/write registers, which indicate the table
locations. Before accessing the table, the location has
to be placed in TBHP and TBLP. The TBLH is read
only and cannot be restored. If the main routine and
the ISR (interrupt service routine) both employ the table read instruction, the contents of TBLH in the main
routine are likely to be changed by the table read instruction used in the ISR. Errors are thus brought
Instruction
D e v ic e In itia liz a tio n P r o g r a m
If the stack is full and a non-masked 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
Table Location
*14~*8
*7
*6
*5
*4
*3
*2
*1
*0
TABRDC [m]
TBHP
@7
@6
@5
@4
@3
@2
@1
@0
TABRDL [m]
1011111
@7
@6
@5
@4
@3
@2
@1
@0
Table Location
Note: *14~*0: Table location bits
Rev. 1.30
@[email protected]: Table pointer bits
7
October 12, 2007
HT48RA3/HT48CA3
In d ir e c t A d d r e s s in g R e g is te r 0
will be serviced. This feature prevents stack overflow allowing the programmer to use the structure more easily.
In a similar case, if the stack is full and a ²CALL² is subsequently executed, stack overflow occurs and the first
entry will be lost (only the most recent 8 return addresses are stored).
0 0 H
0 6 H
P C L
Data Memory - RAM
0 7 H
T B L P
The data memory is designed with 250´8 bits. The
data memory is divided into two functional groups: special function registers and general purpose data memory (224´8). Most are read/write, but some are read
only.
0 1 H
M P 0
0 2 H
In d ir e c t A d d r e s s in g R e g is te r 1
0 3 H
M P 1
0 4 H
B P
0 5 H
A C C
0 8 H
T B L H
0 9 H
W D T S
0 A H
S T A T U S
0 B H
IN T C
0 C H
The special function registers include the indirect addressing registers (R0;00H, R1;02H) bank pointer (BP;
0 4 H ) , Ti m e r / E v e n t C o u n t e r 0 ( T M R 0 ; 0 D H ) ,
Timer/Event Counter 0 control register (TMR0C;0EH),
Timer/Event Counter 1 higher order byte register
(TMR1H;0FH), Timer/Event Counter 1 lower order byte
register (TMR1L;10H), Timer/Event Counter 1 control
register (TMR1C;11H), program counter lower-order
byte register (PCL;06H), memory pointer registers
(MP0;01H, MP1;03H), accumulator (ACC;05H), table
pointer (TBLP;07H, TBHP;1FH), table higher-order
byte register (TBLH;08H), status register (STATUS;
0AH), interrupt control register (INTC;0BH), Watchdog
Timer option setting register (WDTS;09H), I/O registers (PA;12H, PB;14H, PC;16H, PF;1CH), and I/O control registers (PAC;13H, PBC;15H, PCC;17H,
PFC;1DH). The remaining space before the 20H is reserved for future expanded usage and reading these
locations will get ²00H². The general purpose data
memory, addressed from 20H to FFH, is used for data
and control information under instruction commands.
0 D H
T M R 0
0 E H
T M R 0 C
0 F H
T M R 1 H
1 0 H
T M R 1 L
1 1 H
T M R 1 C
1 2 H
P A
1 3 H
P A C
1 4 H
P B
1 5 H
P B C
1 6 H
P C
1 7 H
P C C
S p e c ia l P u r p o s e
D A T A M E M O R Y
1 8 H
1 9 H
: U n u s e d
1 A H
1 B H
1 C H
P F
1 D H
P F C
R e a d a s "0 0 "
1 E H
1 F H
2 0 H
T B H P
G e n e ra l P u rp o s e
D A T A M E M O R Y
(2 2 4 B y te s )
All of the data memory areas can handle arithmetic,
logic, increment, decrement and rotate operations directly. Except for some dedicated bits, each bit in the
data memory can be set and reset by ²SET [m].i² and
²CLR [m].i². They are also indirectly accessible through
memory pointer registers (MP0 or MP1).
F F H
RAM Mapping
ment between two data memory locations must pass
through the accumulator.
Indirect Addressing Register
Arithmetic and Logic Unit - ALU
Location 00H and 02H are indirect addressing registers
that are not physically implemented. Any read/write operation of [00H] ([02H]) will access data memory pointed
to by MP0 (MP1). Reading location 00H (02H) itself indirectly will return the result 00H. Writing indirectly results
in no operation.
This circuit performs 8-bit arithmetic and logic operations. The ALU provides the following functions:
· Arithmetic operations (ADD, ADC, SUB, SBC, DAA)
· Logic operations (AND, OR, XOR, CPL)
· Increment and decrement (INC, DEC)
The memory pointer registers (MP0 and MP1) are 8-bit
registers.
· Rotation (RL, RR, RLC, RRC)
· Increment and Decrement (INC, DEC)
Accumulator
· Branch decision (SZ, SNZ, SIZ, SDZ ....)
The accumulator is closely related to ALU operations. It
is also mapped to location of the data memory and can
carry out immediate data operations. The data move-
The ALU not only saves the results of a data operation
but also changes the status register.
Rev. 1.30
8
October 12, 2007
HT48RA3/HT48CA3
Status Register - STATUS
the interrupt request flag is recorded. If a certain interrupt requires servicing within the service routine, the
EMI bit and the corresponding bit of the INTC may be set
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 SP is decremented. If immediate service is desired, the stack must be prevented from
becoming full.
This 8-bit register (0AH) 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). It also records the status information and controls
the operation sequence.
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 from those intended. The TO flag
can be affected only by system power-up, a WDT
time-out or executing the ²CLR WDT² or ²HALT² instruction. The PDF flag can be affected only by executing the ²HALT² or ²CLR WDT² instruction or
during a system power-up.
All these kinds of interrupts have a wake-up capability.
As an interrupt is serviced, a control transfer occurs by
pushing the program counter onto the stack, followed by
a branch to a subroutine at specified location in the program memory. Only the program counter is pushed onto
the stack. If the contents of the register or status register
(STATUS) are altered by the interrupt service program
which corrupts the desired control sequence, the contents should be saved in advance.
External interrupts are triggered by a high to low transition of the INT and the related interrupt request flag (EIF;
bit 4 of INTC) will be set. When the interrupt is enabled,
the stack is not full and the external interrupt is active, a
subroutine call to location 04H will occur. The interrupt
request flag (EIF) and EMI bits will be cleared to disable
other interrupts.
The Z, OV, AC and C flags generally reflect the status of
the latest operations.
In addition, on entering the interrupt sequence or executing the subroutine call, the status register will not be
pushed onto the stack automatically. If the contents of
the status are important and if the subroutine can corrupt the status register, precautions must be taken to
save it properly.
The internal Timer/Event Counter 0 interrupt is initialized by setting the Timer/Event Counter 0 interrupt request flag (T0F; bit 5 of INTC), caused by a timer 0
overflow. When the interrupt is enabled, the stack is not
full and the T0F bit is set, a subroutine call to location
08H will occur. The related interrupt request flag (T0F)
will be reset and the EMI bit cleared to disable further interrupts.
Interrupt
The device provides an external interrupt and internal
timer/event counter interrupts. The Interrupt Control
Register (INTC;0BH) contains the interrupt control bits
to set the enable or disable and the interrupt request
flags.
The internal Timer/Event Counter 1 interrupt is initialized by setting the Timer/Event Counter 1 interrupt request flag (T1F;bit 6 of INTC), caused by a timer 1
overflow. When the interrupt is enabled, the stack is not
full and the T1F is set, a subroutine call to location 0CH
Once an interrupt subroutine is serviced, all the other interrupts will be blocked (by clearing the EMI bit). This
scheme may prevent any further interrupt nesting. Other
interrupt requests may occur during this interval but only
Bit No.
Labels
Function
0
C
C is set if the operation results in a carry during an addition operation or if a borrow does not
take place during a subtraction operation; otherwise C is cleared. C is also affected by a rotate through carry instruction.
1
AC
AC is set if the operation results in a carry out of the low nibbles in addition or no borrow from
the high nibble into the low nibble in subtraction; otherwise AC is cleared.
2
Z
Z is set if the result of an arithmetic or logic operation is zero; otherwise Z is cleared.
3
OV
OV is set if the operation results in a carry into the highest-order bit but not a carry out of the
highest-order bit, or vice versa; otherwise OV is cleared.
4
PDF
PDF is cleared by system power-up or executing the ²CLR WDT² instruction. PDF is set by
executing the ²HALT² instruction.
5
TO
TO is cleared by system power-up or executing the ²CLR WDT² or ²HALT² instruction. TO is
set by a WDT time-out.
6
¾
Unused bit, read as ²0²
7
¾
Unused bit, read as ²0²
Status (0AH) Register
Rev. 1.30
9
October 12, 2007
HT48RA3/HT48CA3
Oscillator Configuration
will occur. The related interrupt request flag (T1F) will be
reset and the EMI bit cleared to disable further interrupts.
There are 2 oscillator circuits implemented in the microcontroller.
During the execution of an interrupt subroutine, other interrupt acknowledge signals are held until the ²RETI² instruction is executed or the EMI bit and the related
interrupt control bit are set to 1 (if the stack is not full). To
return from the interrupt subroutine, ²RET² or ²RETI²
may be invoked. RETI will set the EMI bit to enable an interrupt service, but RET will not.
O S C 1
O S C 2
C r y s ta l O s c illa to r
Interrupt Source
Priority
Vector
1
04H
Timer/Event Counter 0 Overflow
2
08H
Timer/Event Counter 1 Overflow
3
0CH
fS Y S /4
N M O S O p e n D r a in
O S C 2
R C O s c illa to r
System Oscillator
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 the case of simultaneous requests
the following table shows the priority that is applied.
These can be masked by resetting the EMI bit.
External Interrupt
O S C 1
Both of them are designed for system clocks, namely
the RC oscillator and the crystal oscillator, which are determined by options. No matter what oscillator type is
selected, the signal provides the system clock. The
HALT mode stops the system oscillator and resists the
external signal to conserve power.
If an RC oscillator is used, an external resistor between
OSC1 and VSS is required and the resistance should
range from 100kW to 820kW. The system clock, divided
by 4, is available on OSC2, which can be used to synchronize external logic. The internal RC oscillator provides the most cost effective solution. However, the
frequency of oscillation may vary with VDD, temperatures and the chip itself due to process variations. It is,
therefore, not suitable for timing sensitive operations
where an accurate oscillator frequency is desired.
The Timer/Event Counter 0/1 interrupt request flag
(T0F/T1F), external interrupt request flag (EIF), enable
Timer/Event Counter 0/1 interrupt bit (ET0I/ET1I), enable external interrupt bit (EEI) and enable master interrupt bit (EMI) constitute an interrupt control register
(INTC) which is located at 0BH in the data memory. EMI,
EEI, ET0I and ET1I are used to control the enabling/disabling of interrupts. These bits prevent the requested interrupt from being serviced. Once the interrupt request
flags (T0F, T1F, EIF) are set, they will remain in the INTC
register until the interrupts are serviced or cleared by a
software instruction.
If the crystal oscillator is used, a crystal across OSC1
and OSC2 is needed to provide the feedback and phase
shift required for the oscillator, and no other external
components are demanded. Instead of a crystal, the
resonator can also be connected between OSC1 and
OSC2 to get a frequency reference, but two external capacitors in OSC1 and OSC2 are required.
It is recommended that a program does not use the
²CALL subroutine² 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 enabling the interrupt is not
well controlled, the original control sequence will be damaged once the ²CALL² operates in the interrupt subroutine.
The WDT oscillator is a free running on-chip RC oscillator, and no external components are required. Even if
the system enters the power down mode, the system
clock is stopped, but the WDT oscillator still works with a
period of approximately 90ms. The WDT oscillator can
be disabled by ROM code option to conserve power.
Bit No.
Label
Function
0
EMI
Controls the master (global) interrupt (1= enabled; 0= disabled)
1
EEI
Controls the external interrupt (1= enabled; 0= disabled)
2
ET0I
Controls the Timer/Event Counter 0 interrupt (1= enabled; 0= disabled)
3
ET1I
Controls the Timer/Event Counter 1 interrupt (1= enabled; 0= disabled)
4
EIF
External interrupt request flag (1= active; 0= inactive)
5
T0F
Internal Timer/Event Counter 0 request flag (1= active; 0= inactive)
6
T1F
Internal Timer/Event Counter 1 request flag (1= active; 0= inactive)
7
¾
Unused bit, read as ²0²
INTC (0BH) Register
Rev. 1.30
10
October 12, 2007
HT48RA3/HT48CA3
Watchdog Timer - WDT
The WDT overflow under normal operation will initialize
²chip reset² and set the status bit ²TO². But in the HALT
mode, the overflow will initialize a ²warm reset² and only
the program counter and SP are reset to zero. To clear
the contents of WDT (including the WDT prescaler),
three methods are adopted; external reset (a low level to
RES), software instruction and a ²HALT² instruction.
The software instruction include ²CLR WDT² and the
other set - ²CLR WDT1² and ²CLR WDT2². Of these
two types of instruction, only one can be active depending on the ROM code option - ²CLR WDT times selection option². If the ²CLR WDT² is selected (i.e. CLRWDT
times equal one), any execution of the ²CLR WDT² instruction will clear the WDT. In the case that ²CLR
WDT1² and ²CLR WDT2² are chosen (i.e. CLRWDT
times equal two), these two instructions must be executed to clear the WDT; otherwise, the WDT may reset
the chip as a result of time-out.
The WDT clock source is implemented by a dedicated
RC oscillator (WDT oscillator), instruction clock (system
clock divided by 4), determines the ROM code option.
This timer is designed to prevent a software malfunction
or sequence from jumping to an unknown location with
unpredictable results. The Watchdog Timer can be disabled by ROM code option. If the Watchdog Timer is disabled, all the executions related to the WDT result in no
operation.
Once the internal WDT oscillator (RC oscillator with a
period of 90ms at 3V normally) is selected, it is first divided by 256 (8-stage) to get the nominal time-out period of 23ms at 3V. This time-out period may vary with
temperatures, VDD and process variations. By invoking
the WDT prescaler, longer time-out periods can be realized. Writing data to WS2, WS1, WS0 (bit 2,1,0 of the
WDTS) can give different time-out periods. If WS2,
WS1, and WS0 are all equal to 1, the division ratio is up
to 1:128, and the maximum time-out period is 2.9s/3V
seconds. If the WDT oscillator is disabled, the WDT
clock may still come from the instruction clock and operates in the same manner except that in the HALT state
the WDT may stop counting and lose its protecting purpose. In this situation the logic can only be restarted by
external logic. The high nibble and bit 3 of the WDTS are
reserved for user¢s defined flags, which can be used to
indicate some specified status.
Power Down Operation - HALT
The HALT mode is initialized by the ²HALT² instruction
and results in the following...
· The system oscillator will be turned off but the WDT
oscillator remains running (if the WDT oscillator is selected).
· The contents of the on chip RAM and registers remain
unchanged.
· WDT and WDT prescaler will be cleared and re-
If the device operates in a noisy environment, using the
on-chip RC oscillator (WDT OSC) is strongly recommended, since the HALT will stop the system clock.
WS2
WS1
WS0
Division Ratio
0
0
0
1:1
0
0
1
1:2
0
1
0
1:4
0
1
1
1:8
1
0
0
1:16
1
0
1
1:32
1
1
0
1:64
1
1
1
1:128
counted again (if the WDT clock is from the WDT oscillator).
· All of the I/O ports maintain their original status.
· The PDF flag is set and the TO flag is cleared.
The system can leave the HALT mode by means of an
external reset, an interrupt, an external falling edge signal on port A or a WDT overflow. An external reset
causes a device initialization and the WDT overflow performs a ²warm reset². After the TO and PDF flags are
examined, the reason for chip reset can be determined.
The PDF flag is cleared by system power-up or executing the ²CLR WDT² instruction and is set when executing the ²HALT² instruction. The TO flag is set if the WDT
time-out occurs, and causes a wake-up that only resets
the program counter and SP; the others remain in their
original status.
WDTS Register
S y s te m
C lo c k /4
W D T
O S C
R O M
C o d e
O p tio n
S e le c t
W D T P r e s c a le r
8 - b it C o u n te r
7 - b it C o u n te r
8 -to -1 M U X
W S 0 ~ W S 2
W D T T im e - o u t
Watchdog Timer
Rev. 1.30
11
October 12, 2007
HT48RA3/HT48CA3
The port A wake-up and interrupt methods can be considered as a continuation of normal execution. Each bit
in port A can be independently selected to wake up the
device by options. Awakening from an I/O port stimulus,
the program will resume execution of the next instruction. If it awakens from an interrupt, two sequence may
occur. If the related interrupt is disabled or the interrupt
is enabled but the stack is full, the program will resume
execution at the next instruction. If the interrupt is enabled and the stack is not full, the regular interrupt response takes place. If an interrupt request flag is set to
²1² before entering the HALT mode, the wake-up function of the related interrupt will be disabled. Once a
wake-up event occurs, it takes 1024 tSYS (system clock
period) to resume normal operation. In other words, a
dummy period will be inserted after a wake-up. If the
wake-up results from an interrupt acknowledge signal,
the actual interrupt subroutine execution will be delayed
by one or more cycles. If the wake-up results in the next
instruction execution, this will be executed immediately
after the dummy period is finished.
An extra option load time delay is added during system
reset (power-up, WDT time-out at normal mode or RES
reset).
The functional unit chip reset status are shown below.
Program Counter
000H
Interrupt
Disable
Prescaler
Clear
WDT
Clear. After master reset,
WDT begins counting
Timer/Event Counter
Off
Input/Output Ports
Input mode
Stack Pointer
Points to the top of the stack
V
V
D D
0 .0 1 m F
1 0 0 k W
To minimize power consumption, all the I/O pins should
be carefully managed before entering the HALT status.
1 0 0 k W
R E S
· RES reset during normal operation
Note:
· WDT time-out reset during normal operation
The WDT time-out during HALT is different from other
chip reset conditions, since it can perform a ²warm re set² that resets only the program counter and SP, leaving the other circuits in their original state. Some registers remain unchanged during other reset conditions.
Most registers are reset to the ²initial condition² when
the reset conditions are met. By examining the PDF and
TO flags, the program can distinguish between different
²chip resets².
0
RES reset during power-up
u
u
RES reset during normal operation
0
1
RES wake-up HALT
1
u
WDT time-out during normal operation
1
1
WDT wake-up HALT
Most applications can use the Basic Reset Circuit as shown, however for applications with extensive noise, it is recommended to use the
Hi-noise Reset Circuit.
V D D
R E S
tS
S T
S S T T im e - o u t
RESET Conditions
C h ip
R e s e t
Reset Timing Chart
H A L T
W a rm
R e s e t
W D T
Note: ²u² stands for ²unchanged²
R E S
To guarantee that the system oscillator is started and
stabilized, the SST (System Start-up Timer) provides an
extra-delay of 1024 system clock pulses when the system reset (power-up, WDT time-out or RES reset) or the
system awakes from the HALT state.
O S C 1
C o ld
R e s e t
S S T
1 0 - b it R ip p le
C o u n te r
S y s te m
When a system reset occurs, the SST delay is added
during the reset period. Any wake-up from HALT will enable the SST delay.
Rev. 1.30
H i-n o is e
R e s e t
C ir c u it
0 .1 m F
Reset Circuit
· RES reset during HALT
PDF
1 0 k W
B a s ic
R e s e t
C ir c u it
There are three ways in which a reset can occur:
0
R E S
0 .1 m F
Reset
TO
D D
R e s e t
Reset Configuration
12
October 12, 2007
HT48RA3/HT48CA3
The states of the registers is summarized in the table.
Reset
(Power On)
WDT Time-out
(Normal Operation)
RES Reset
(Normal Operation)
RES Reset
(HALT)
WDT Time-out
(HALT)*
MP0
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
MP1
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
BP
0000 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
ACC
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
0000H
0000H
0000H
0000H
0000H
TBLP
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
TBHP
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
TBLH
xxxx xxxx
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
WDTS
0000 0111
0000 0111
0000 0111
0000 0111
uuuu uuuu
Register
Program
Counter
STATUS
--00 xxxx
--1u uuuu
--uu uuuu
--01 uuuu
--11 uuuu
INTC
-000 0000
-000 0000
-000 0000
-000 0000
-uuu uuuu
TMR0
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
TMR0C
00-0 1000
00-0 1000
00-0 1000
00-0 1000
uu-u uuuu
TMR1H
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
TMR1L
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
TMR1C
00-0 1---
00-0 1---
00-0 1---
00-0 1---
uu-u u---
PA
1111 1111
1111 1111
1111 1111
1111 1111
uuuu uuuu
PAC
1111 1111
1111 1111
1111 1111
1111 1111
uuuu uuuu
PB
1111 1111
1111 1111
1111 1111
1111 1111
uuuu uuuu
PBC
1111 1111
1111 1111
1111 1111
1111 1111
uuuu uuuu
PC
--11 1111
--11 1111
--11 1111
--11 1111
--uu uuuu
PCC
--11 1111
--11 1111
--11 1111
--11 1111
--uu uuuu
PF
---- ---1
---- ---1
---- ---1
---- ---1
---- ---u
PFC
---- ---1
---- ---1
---- ---1
---- ---1
---- ---u
Note:
²*² stands for ²warm reset²
²u² stands for ²unchanged²
²x² stands for ²unknown²
Rev. 1.30
13
October 12, 2007
HT48RA3/HT48CA3
0 preload register and issues the interrupt request just
like the other two modes.
Timer/Event Counter
Two timer/event counters are (TMR0, TMR1) implemented in the device. The Timer/Event Counter 0 contains an 8-bit programmable count-up counter and the
clock may come from an external source or the system
clock. The Timer/Event Counter 1 contains an 16-bit
programmable count-up counter and the clock may
come from an external source or the system clock divided by 4.
To enable the counting operation, the timer ON bit
(T0ON; bit 4 of TMR0C) should be set to 1. In the pulse
width measurement mode, the T0ON will be cleared automatically after the measurement cycle is complete.
But in the other two modes the T0ON can only be reset
by instructions. The overflow of the Timer/Event Counter 0 is one of the wake-up sources. No matter what the
operation mode is, writing a 0 to ET0I can disabled the
corresponding interrupt service.
Of the two timer/event counters, using external clock input allows the user to count external events, measure
time internals or pulse widths, or generate an accurate
time base. While using the internal clock allows the user
to generate an accurate time base.
In the case of Timer/Event Counter 0 OFF condition,
writing data to the Timer/Event Counter 0 preload register will also load the data to Timer/Event Counter 0. But
if the Timer/Event Counter 0 is turned on, data written to
the Timer/Event Counter 0 will only be kept in the
Ti m e r / E ve n t C o u n t e r 0 preload r e g i st e r. T h e
Timer/Event Counter 0 will still operate until the overflow
occurs (a Timer/Event Counter 0 reloading will occur at
the same time).
Only the Timer/Event Counter 0 can generate PFD signal by using external or internal clock, and PFD frequency is determine by the equation fINT/[2´(256-N)].
There are 2 registers related to Timer/Event Counter 0;
TMR0(0DH), TMR0C(0EH). In Timer/Event Counter 0
counting mode (T0ON=1), writing TMR0 will only put the
written data to preload register (8 bits). The Timer/Event
Counter 0 preload register is changed by each writing
TMR0 operations. Reading TMR0 will also latch the
TMR0 to the destination. The TMR0C is the Timer/Event
Counter 0 control register, which defines the operating
mode, counting enable or disable and active edge.
When the Timer/Event Counter 0 (reading TMR0) is
read, the clock will be blocked to avoid errors. As this
may results in a counting error, this must be taken into
consideration by the programmer.
The bit 0~2 of the TMR0C can be used to define the
pre-scaling stages of the internal clock sources of
Timer/Event Counter 0. The definitions are as shown.
The T0M0, T0M1 bits define the operating mode. The
event count mode is used to count external events,
which means the clock source comes from an external
(TMR0) pin. The timer mode functions as a normal timer
with the clock source coming from the fINT clock. The
pulse width measurement mode can be used to count
the high or low level duration of the external signal
(TMR0). The counting is based on the fINT clock.
Bit
No.
Function
To define the prescaler stages,
T0PSC2, T0PSC1, T0PSC0=
000: fINT=fSYS/2
001: fINT=fSYS/4
T0PSC0~ 010: fINT=fSYS/8
0~2
T0PSC2 011: fINT=fSYS/16
100: fINT=fSYS/32
101: fINT=fSYS/64
110: fINT=fSYS/128
111: fINT=fSYS/256
In the event count or timer mode, once the Timer/Event
Counter 0 starts counting, it will count from the current
contents in the Timer/Event Counter 0 to FFH. Once
overflow occurs, the counter is reloaded from the
Timer/Event Counter 0 preload register and generates
the corresponding interrupt request flag (T0F; bit 5 of
INTC) at the same time.
In pulse width measurement mode with the T0ON and
T0E bits are equal to one, once the TMR0 has received
a transition from low to high (or high to low if the T0E bit
is 0) it will start counting until the TMR0 returns to the
original level and reset the T0ON. The measured result
will remain in the Timer/Event Counter 0 even if the activated transition occurs again. In other words, only one
cycle measurement can be done. Until setting the
T0ON, the cycle measurement will function again as
long as it receives further transition pulse. Note that, in
this operating mode, the Timer/Event Counter 0 starts
counting not according to the logic level but according to
the transition edges. In the case of counter overflows,
the counter 0 is reloaded from the Timer/Event Counter
Rev. 1.30
Label
3
T0E
To define the TMR0 active edge of
Timer/Event Counter 0
(0=active on low to high;
1=active on high to low)
4
T0ON
To enable/disable timer 0 counting
(0=disabled; 1=enabled)
5
¾
6
7
T0M0
T0M1
Unused bit, read as ²0²
To define the operating mode
(T0M1, T0M0)
01=Event count mode
(external clock)
10=Timer mode (internal clock)
11=Pulse width measurement mode
00=Unused
TMR0C (0EH) Register
14
October 12, 2007
HT48RA3/HT48CA3
In pulse width measurement mode with the T1ON and
T1E bits are equal to one, once the TMR1 has received
a transition from low to high (or high to low if the T1E bit
is 0) it will start counting until the TMR1 returns to the
original level and reset the T1ON. The measured result
will remain in the Timer/Event Counter 1 even if the activated transition occurs again. In other words, only one
cycle measurement can be done. Until setting the
T1ON, the cycle measurement will function again as
long as it receives further transition pulse. Note that, in
this operating mode, the Timer/Event Counter 1 starts
counting not according to the logic level but according to
the transition edges. In the case of counter overflows,
the counter 1 is reloaded from the Timer/Event Counter
1 preload register and issues the interrupt request just
like the other two modes.
There are 3 registers related to Timer/Event Counter 1;
TMR1H (0FH), TMR1L (10H), TMR1C (11H). Writing
TMR1L will only put the written data to an internal
lower-order byte buffer (8 bits) and writing TMR1H will
transfer the specified data and the contents of the
lower-order byte buffer to TMR1H and TMR1L preload
registers, respectively. The Timer/Event Counter 1
preload register is changed by each writing TMR1H operations. Reading TMR1H will latch the contents of
TMR1H and TMR1L counters to the destination and the
lower-order byte buffer, respectively. Reading the
TMR1L will read the contents of the lower-order byte
buffer. The TMR1C is the Timer/Event Counter 1 control
register, which defines the operating mode, counting enable or disable and active edge.
The T1M0, T1M1 bits define the operating mode. The
event count mode is used to count external events,
which means the clock source comes from an external
(TMR1) pin. The timer mode functions as a normal timer
with the clock source coming from the instruction clock.
The pulse width measurement mode can be used to
count the high or low level duration of the external signal
(TMR1). The counting is based on the instruction clock.
To enable the counting operation, the timer ON bit
(T1ON; bit 4 of TMR1C) should be set to 1. In the pulse
width measurement mode, the T1ON will be cleared automatically after the measurement cycle is complete.
But in the other two modes the T1ON can only be reset
by instructions. The overflow of the Timer/Event Counter 1 is one of the wake-up sources. No matter what the
operation mode is, writing a 0 to ET1I can disabled the
corresponding interrupt service.
In the event count or timer mode, once the Timer/Event
Counter 1 starts counting, it will count from the current
contents in the Timer/Event Counter 1 to FFFFH. Once
overflow occurs, the counter is reloaded from the
Timer/Event Counter 1 preload register and generates
the corresponding interrupt request flag (T1F; bit 6 of
INTC) at the same time.
In the case of Timer/Event Counter 1 OFF condition,
writing data to the Timer/Event Counter 1 preload register will also load the data to Timer/Event Counter 1. But
if the Timer/Event Counter 1 is turned on, data written to
the Timer/Event Counter 1 will only be kept in the
(1 /2 ~ 1 /2 5 6 )
fS
Y S
8 - s ta g e P r e s c a le r
f IN
8 -1 M U X
T 0 P S C 2 ~ T 0 P S C 0
D a ta B u s
T
T 0 M 1
T 0 M 0
T M R 0
T im e r /E v e n t C o u n te r 0
P r e lo a d R e g is te r
R e lo a d
T 0 E
T 0 M 1
T 0 M 0
T 0 O N
P u ls e W id th
M e a s u re m e n t
M o d e C o n tro l
8 - b it
T im e r /E v e n t C o u n te r
(T M R 0 )
O v e r flo w to In te r r u p t
¸ 2
P F D
Timer/Event Counter 0
D a ta B u s
T 1 M 1
fS Y S /4
T 1 M 0
T M R 1
1 6 - b it
T im e r /E v e n t C o u n te r
P r e lo a d R e g is te r
R e lo a d
T 1 E
T 1 M 1
T 1 M 0
T 1 O N
L o w B y te
B u ffe r
P u ls e W id th
M e a s u re m e n t
M o d e C o n tro l
1 6 - b it
T im e r /E v e n t C o u n te r
(T M R 1 H /T M R 1 L )
O v e r flo w
to In te rru p t
Timer/Event Counter 1
Rev. 1.30
15
October 12, 2007
HT48RA3/HT48CA3
Timer/Event Counter 1 preload register. The
Timer/Event Counter 1 will still operate until the overflow
occurs (a Timer/Event Counter 1 reloading will occur at
the same time).
at the T2 rising edge of instruction ²MOV A,[m]² (m =
12H, 14H, 16H or 1CH). For output operation, all the
data is latched and remains unchanged until the output
latch is rewritten.
When the Timer/Event Counter 1 (reading TMR1H) is
read, the clock will be blocked to avoid errors. As this
may results in a counting error, this must be taken into
consideration by the programmer.
Each I/O line has its own control register (PAC, PBC,
PCC, PFC) to control the input/output configuration.
With this control register, CMOS output or Schmitt trigger input with or without (depends on options) pull-high
resistor structures can be reconfigured dynamically (i.e.,
on-the fly) under software control. To function as an input, the corresponding latch of the control register has to
be set as ²1². The pull-high resistor (if the pull-high resistor is enabled) will be exhibited automatically. The input sources also depends on the control register. If the
control register bit is ²1², the input will read the pad state
(²mov² and read-modify-write instructions). If the control
register bit is 0, the contents of the latches will move to
internal data bus (²mov² and read-modify-write instructions). The input paths (pad state or latches) of
read-modify-write instructions are dependent on the
control register bits. For output function, CMOS is the
only configuration. These control registers are mapped
to locations 13H, 15H, 17H and 1DH.
The definitions of the TMR1C are as shown.
Bit No. Label
0~2
Function
¾
Unused bit, read as ²0²
3
T1E
To define the active edge of TMR1 pin
input signal
(0/1: active on low to high/high to low)
4
T1ON
To enable/disable timer 1 counting
(0/1: disabled/enabled)
5
¾
6
7
Unused bit, read as ²0²
T1M0
T1M1
To define the operating mode
(T1M1, T1M0)
01=Event count mode (external clock)
10=Timer mode (internal clock)
11=Pulse width measurement mode
00=Unused
After a chip reset, these input/output lines stay at high
levels (pull-high options) or floating state (non-pull-high
options). Each bit of these input/output latches can be
set or cleared by ²SET [m].i² (m=12H, 14H, 16H or 1CH)
instructions. Some instructions first input data and then
follow the output operations. For example, ²SET [m].i²,
²CLR [m].i², ²CPLA [m]² read the entire port states into
the CPU, execute the defined operations (bit-operation),
and then write the results back to the latches or the accumulator.
TMR1C (11H) Register
Input/Output Ports
There are 23 bi-directional input/output lines in the micro-controller, labeled from PA to PC and PF, which are
mapped to the data memory of [12H], [14H], [16H] and
[1CH], respectively. All of these I/O ports can be used as
input and output operations. For input operation, these
ports are non-latching, that is, the inputs must be ready
V
C o n tr o l B it
D a ta B u s
P U
Q
D
C K
W r ite C o n tr o l R e g is te r
Q B
S
C h ip R e s e t
R e a d C o n tr o l R e g is te r
P A 0
P B 0
P B 1
P C 0
P F 0
D a ta B it
Q
D
C K
W r ite D a ta R e g is te r
R e a d D a ta R e g is te r
S y s te m W a k e -u p
( P A o n ly )
P B 0
P F D
~ P
/P
~ P
~ P
A 7
F D
B 7
C 5
Q B
S
( P B 0 O n ly )
D D
M
M
U
U
X
P F D E N
( P B 0 O n ly )
X
O P 0 ~ O P 7
IN T fo r P F 0 O n ly
P F D
fo r P B 0 o n ly , c o n tr o l= P B 0 d a ta r e g is te r
Input/Output Ports
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When calling a subroutine or an interrupt event occurring, the contents of the program counter are save into
stack registers. If a returning from subroutine occurs,
the contents of the program counter will restore from
stack registers.
Each line of port A has the capability of waking-up the
device. The highest 2 bits of port C and 7 bits of port F
are not physically implemented; on reading them a ²0² is
returned whereas writing then results in a no-operation.
Pull-high resistors of each port are decided by an option
bit.
Low Voltage Reset - LVR
The PB0 is pin-shared with PFD signal, respectively. If
the PFD option is selected, the output signal in output
mode of PB0 will be the PFD signal. The input mode always remain its original functions. The PF0 and PC0 are
pin-shared with INT and TMR 0. The INT signal is directly connected to PF0. The PFD output signal (in output mode) are controlled by the PB0 data register only.
The truth table of PB0/PFD is listed below.
The microcontroller provides low voltage reset circuit in
order to monitor the supply voltage of the device. If the
supply voltage of the device is within the range
0.9V~VLVR, such as changing a battery, the LVR will automatically reset the device internally.
The LVR includes the following specifications:
· The low voltage (0.9V~VLVR) has to remain in their
original state to exceed 1ms. If the low voltage state
does not exceed 1ms, the LVR will ignore it and do not
perform a reset function.
The truth table of PB0/PFD is as shown.
PBC (15H) Bit0
I
O
O
O
PB0/PFD Option
x
PB0
PFD
PFD
PB0 (14H) Bit0
x
D
0
1
PB0 Pad Status
Note:
I
D
0
· The LVR uses the ²OR² function with the external
RES signal to perform chip reset.
The relationship between VDD and VLVR is shown below.
PFD
V D D
5 .5 V
I: Input; O: Output; D: Data
Bank Pointer
There is a bank pointer used to control the program flow
to go to any banks. A bank contains 8K´16 address
space. The contents of bank pointer are load into program counter when the JMP or CALL instruction is executed. The program counter is a 15-bit register whose
contents are used to specify the executed instruction
addresses.
V
V
L V R
1 .8 V
0 .9 V
D D
5 .5 V
V
L V R
L V R
D e te c t V o lta g e
0 .9 V
0 V
R e s e t S ig n a l
N o r m a l O p e r a tio n
R e s e t
*1
R e s e t
*2
Low Voltage Reset
Note:
²*1² To make sure that the system oscillator has stabilized, the SST provides an extra delay of 1024 system
clock pulses before entering the normal operation.
²*2² Since low voltage has to be maintained in its original state and exceed 1ms, therefore 1ms delay enters
the reset mode.
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Options
The following table shows all kinds of options in the MCU. All of the options must be defined to ensure proper system
functioning.
Function
PA0~PA7 wake-up enable or disable
PC pull-high enable or disable
PA pull-high enable or disable: Byte option
PF pull-high enable or disable
PB pull-high (PB0~PB3, PB4~PB7) enable or disable: Nibble option
PB0 or PFD
CLR WDT instructions
System oscillators: RC or crystal
WDT enable or disable
WDT clock source: WDTOSC or system clock/4 (T1D)
LVR function: enable or disable
LVR voltage: 2.0V or 3.0V
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HT48RA3/HT48CA3
Application Circuits
V
D D
V D D
R e s e t
C ir c u it
1 0 0 k W
0 .1 m F
R E S
0 .1 m F
V
4 7 0 p F
P A 0 ~ P A 7
P B 0 /P F D
R
P B 1 ~ P B 7
P C 0 /T M R 0
V S S
O S C
O S C 1
fS
C 1
P C 1 ~ P C 4
P C 5 /T M R 1
P F 0 /IN T
O S C
C ir c u it
D D
Y S
/4
O S C 1
R 1
S C
O s c illa to r
< 8 2 0 k W
O S C 2
C 2
O S C 1
R C S y s te m
1 0 0 k W < R O
O S C 2
C r y s ta l/R e s o n a to r
S y s te m O s c illa to r
F o r R 1 , C 1 , C 2 s e e n o te
O S C 2
O S C C ir c u it
H T 4 8 R A 3 /H T 4 8 C A 3
Note:
1. Crystal/resonator system oscillators
For crystal oscillators, C1 and C2 are only required for some crystal frequencies to ensure oscillation. For
resonator applications C1 and C2 are normally required for oscillation to occur. For most applications it is
not necessary to add R1. However if the LVR function is disabled, and if it is required to stop the oscillator
when VDD falls below its operating range, it is recommended that R1 is added. The values of C1 and C2
should be selected in consultation with the crystal/resonator manufacturer specifications.
2. Reset circuit
The reset circuit resistance and capacitance values should be chosen to ensure that VDD is stable and remains within its operating voltage range before the RES pin reaches a high level. Ensure that the length of
the wiring connected to the RES pin is kept as short as possible, to avoid noise interference.
3. For applications where noise may interfere with the reset circuit and for details on the oscillator external
components, refer to Application Note HA0075E for more information.
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Example
V
D D
V D D
0 .1 m F
P A 0
R e s e t
C ir c u it
1 0 0 k W
P A 1
P A 2
R E S
P A 3
0 .1 m F
P A 4
P A 5
P A 6
V S S
P A 7
P B 2
P B 3
3 3 W
P B 4
V D D
1 W
1 0 0 m F
P B 5
P B 6
P B 7
V b a t
P C 0 /T M R 0
2 2 0 W ~ 1 k W
O S C
C ir c u it
R e c e iv e r
P C 1
P B 0 /P F D
O S C 1
O S C 2
P F 0 /IN T
( L e a r n in g In p u t)
P C 2
E E P R O M
P C 3
P C 4
P C 5 /T M R 1
H T 4 8 R A 3 /H T 4 8 C A 3
Rev. 1.30
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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 u c c e s s f u l 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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HT48RA3/HT48CA3
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
Z
Z
Z
Z
Z
Z
Z
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
1Note
1Note
1Note
1
1
1
1Note
1
Increment & Decrement
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Mnemonic
INCA [m]
INC [m]
DECA [m]
DEC [m]
Description
Cycles
Flag Affected
Increment Data Memory with result in ACC
Increment Data Memory
Decrement Data Memory with result in ACC
Decrement Data Memory
1
1Note
1
1Note
Z
Z
Z
Z
Rotate Data Memory right with result in ACC
Rotate Data Memory right
Rotate Data Memory right through Carry with result in ACC
Rotate Data Memory right through Carry
Rotate Data Memory left with result in ACC
Rotate Data Memory left
Rotate Data Memory left through Carry with result in ACC
Rotate Data Memory left through Carry
1
1Note
1
1Note
1
1Note
1
1Note
None
None
C
C
None
None
C
C
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
Rev. 1.30
27
October 12, 2007
HT48RA3/HT48CA3
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
Rev. 1.30
28
October 12, 2007
HT48RA3/HT48CA3
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
Rev. 1.30
29
October 12, 2007
HT48RA3/HT48CA3
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. 1.30
30
October 12, 2007
HT48RA3/HT48CA3
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. 1.30
31
October 12, 2007
HT48RA3/HT48CA3
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. 1.30
32
October 12, 2007
HT48RA3/HT48CA3
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. 1.30
33
October 12, 2007
HT48RA3/HT48CA3
Package Information
28-pin SOP (300mil) Outline Dimensions
2 8
1 5
A
B
1
1 4
C
C '
G
H
D
E
Symbol
Rev. 1.30
a
F
Dimensions in mil
Min.
Nom.
Max.
A
394
¾
419
B
290
¾
300
C
14
¾
20
C¢
697
¾
713
D
92
¾
104
E
¾
50
¾
F
4
¾
¾
G
32
¾
38
H
4
¾
12
a
0°
¾
10°
34
October 12, 2007
HT48RA3/HT48CA3
28-pin SSOP (209mil) Outline Dimensions
1 5
2 8
A
B
1 4
1
C
C '
G
H
D
E
Symbol
Rev. 1.30
a
F
Dimensions in mil
Min.
Nom.
Max.
A
291
¾
323
B
196
¾
220
C
9
¾
15
C¢
396
¾
407
D
65
¾
73
E
¾
25.59
¾
F
4
¾
10
G
26
¾
34
H
4
¾
8
a
0°
¾
8°
35
October 12, 2007
HT48RA3/HT48CA3
Product Tape and Reel Specifications
Reel Dimensions
D
T 2
A
C
B
T 1
SOP 28W (300mil)
Symbol
Description
A
Reel Outer Diameter
B
Reel Inner Diameter
Dimensions in mm
330±1.0
62±1.5
13.0+0.5
-0.2
C
Spindle Hole Diameter
D
Key Slit Width
2.0±0.5
T1
Space Between Flange
24.8+0.3
-0.2
T2
Reel Thickness
30.2±0.2
Rev. 1.30
36
October 12, 2007
HT48RA3/HT48CA3
Carrier Tape Dimensions
P 0
D
P 1
t
E
F
W
C
D 1
B 0
P
K 0
A 0
SOP 28W (300mil)
Symbol
Description
Dimensions in mm
W
Carrier Tape Width
24.0±0.3
P
Cavity Pitch
12.0±0.1
E
Perforation Position
1.75±0.1
F
Cavity to Perforation (Width Direction)
11.5±0.1
D
Perforation Diameter
1.5+0.1
D1
Cavity Hole Diameter
1.5+0.25
P0
Perforation Pitch
4.0±0.1
P1
Cavity to Perforation (Length Direction)
2.0±0.1
A0
Cavity Length
10.85±0.1
B0
Cavity Width
18.34±0.1
K0
Cavity Depth
2.97±0.1
t
Carrier Tape Thickness
0.35±0.01
C
Cover Tape Width
Rev. 1.30
21.3
37
October 12, 2007
HT48RA3/HT48CA3
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
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Tel: 886-2-2655-7070
Fax: 886-2-2655-7373
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Fax: 86-21-6485-0313
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Fax: 1-510-252-9885
http://www.holtek.com
Copyright Ó 2007 by HOLTEK SEMICONDUCTOR INC.
The information appearing in this Data Sheet is believed to be accurate at the time of publication. However, Holtek assumes no responsibility arising from the use of the specifications described. The applications mentioned herein are used
solely for the purpose of illustration and Holtek makes no warranty or representation that such applications will be suitable
without further modification, nor recommends the use of its products for application that may present a risk to human life
due to malfunction or otherwise. Holtek¢s products are not authorized for use as critical components in life support devices
or systems. Holtek reserves the right to alter its products without prior notification. For the most up-to-date information,
please visit our web site at http://www.holtek.com.tw.
Rev. 1.30
38
October 12, 2007