Datasheet HT49C50 Datasheet (Holtek Semiconductor Inc)

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Features

Operating voltage: 2.2V~5.2V

8 input lines

12 bidirectional I/O lines

Two external interrupt input

Two 8-bit programmable timer/event

counter with PFD (programmable fre quency divider) function LCD driver with 33 ´ 3or32´ 4 segments

4K ´ 15 program memory ROM

160 ´ 8 data memory RAM

Real Time Clock (RTC)

8-bit prescaler for RTC

Watchdog timer

General Description

The HT49C50 is an 8-bit high performance single chip microcontroller. Its single cycle instruction and two-stage pipeline architecture make it suit able for high speed applications. The device is suited for use in multiple LCD low power applica-

HT49C50

8-Bit Microcontroller

Buzzer output

On-chip crystal and RC oscillator

Halt function and wake-up feature reduce

power consumption 6-level subroutine nesting

Bit manipulation instruction

15-bit table read instruction

Up to 1ms instruction cycle with 4MHz

system clock 63 powerful instructions

All instructions in 1 or 2 machine cycles

80/100-pin QFP package

tions among which are calculators, clock timers, games, scales, leisure products, other hand held LCD products, and battery system in particular.

1 August 18, 1999

Block Diagram

HT49C50

Program

ROM

Instructio n

R egister

Instructio n

D ecoder

Tim ing

Generation

OSC2 OSC1

RES VDD VSS

Program

C ounter

STACK

MUX

ALU

S h ifte r

ACC

LCD DRIVER

M U X

Interrupt

Circuit

DATA

Memory

STATUS

LCD

Memory

IN T C

Tim er CLK0~1

TM R 0 TM R 1

TM R 0C TM R 1C

RTC

WDT

Tim e Base

PORT B

PORT A

M U X

SYS C LK/4

M U X

WDT OSC

TM R 0~1

RTC O SC

PC0~PC3

PB0/IN T0

PB1/IN T1 PB2/TMR 0 PB3/TMR 1

PB4~PB7

PA0/BZ PA1/BZ PA2 PA3/PFD PA4~PA7

OSC3

OSC4

COM 0~ COM 2

COM 3~ SEG32

SEG 0~ SEG 31

2 August 18, 1999

Pin Assignment

NCNCNCNCNC

HT49C50

OSC3

OSC4

OSC2

OSC1

VDD

RES

SEG 0

PA0/BZ PA1/BZ

PA2

PA3/PFD

PA4 PA5 PA6

PA7 PB0/IN T0 PB1/IN T1

PB2/TMR0 PB3/TMR1

PB4

PB5

PB6

PB7

PC0

PC1

PC2

PC3

VSS

NC NC NC

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

26 27 28 29 30 31 32 33 343536

VLCDV1V2C1C2

H T49C 50 8 0 Q F P

COM 0

COM 1

COM 2

65666768697071727374757677787980

SEG 1

SEG 2

SEG 3

SEG 4

SEG 5

SEG 6

SEG 7

SEG 8

SEG 9

SEG 10

SEG 11

SEG 12

SEG 13

SEG 14

SEG 15

SEG 16

SEG 17

SEG 18

SEG 19

SEG 20

SEG 21

SEG 22

SEG 23

SEG 24

SEG 26

SEG 27

SEG 28

SEG 25

SEG 31

SEG 30

SEG 29

37 38 39 40

SEG 32/COM 3

3 August 18, 1999

HT49C50

OSC4

OSC3

OSC2

OSC1

VDD

RES

NC NC NC NC

NC PA0/BZ PA1/BZ

PA2

PA3/PFD

PA4 PA5 PA6

PA7 PB0/INT0 PB1/INT1

PB2/TM R0 PB3/TM R1

PB4

PB5

PB6

PB7

PC0

PC1

PC2

PC3

NC NC NC NC NC

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 4748 49 50

VLCD

VSS

HT49C50 100 Q FP

SEG32/C OM 3

COM 2

COM 1

COM 0C2C1

SEG27

SEG28

SEG29

SEG30

SEG31

81828384858687888990919293949596979899100

SEG0

SEG1

SEG2

SEG3

SEG4

SEG5

SEG6

SEG7

SEG8

SEG9

SEG10

SEG11

SEG12

SEG13

SEG14

SEG15

SEG16

SEG17

SEG18

SEG19

SEG20

SEG21

SEG22

SEG23

SEG24

SEG25

SEG26

4 August 18, 1999

Pad Assignment

PA2

PA4

PA5

PA6

PA7

PB4

PB5

PB6

PB7

PC0

PC1

PC2

PC3

VSS

PA0/BZ

PA1/BZ

PA3/PFD

PB0/IN T0

PB1/IN T1

PB2/TMR 0

PB3/TMR 1

HT49C50

OSC2

COM 1

COM 2

VDD

(0 ,0 )

31 32 33 34 35 36 37

SEG 32/C OM 3

SEG 31

OSC4

OSC3

SEG 30

SEG 29

SEG 28

SEG 27

SEG 26

SEG 25

SEG 0

6162

SEG1

SEG2

SEG3

SEG4

SEG5

SEG6

SEG7

SEG8

SEG9

SEG10

SEG11

SEG12

SEG13

SEG14

SEG15

SEG16

SEG17

SEG18

SEG19

SEG20

SEG21

SEG22

SEG 24

SEG23

OSC1

C1C2COM 0

26 27 28

RES

VLCD

* The IC substrate should be connected to VSS in the PCB layout artwork.

5 August 18, 1999

Pin Description

HT49C50

Pin Name I/O

PA0/BZ PA1/BZ PA2 PA3/PFD PA4~PA7

PB0/INT0 PB1/INT1 PB2/TMR0 PB3/TMR1 PB4~PB7

PC0~PC3 I/O

VSS I

VLCD I

V1,V2,C1,C2 I

SEG32/COM3 COM2~COM0

SEG31~SEG0 O

OSC4 OSC3

VDD

OSC2 OSC1

RES

I/O

¾¾

OICrystal or

Mask

Option

Wake-up Pull-high

or None

CMOS or

NMOS

Pull-high

or None

CMOS or

NMOS

1/3 or 1/4

Duty

Description

PA0~PA7 constitute an 8-bit bidirectional input/output port with Schmitt trigger input capability. Each bit on port can be configured as a wake-up input by mask option. PA0~PA3 can be configured as a CMOS output or NMOS input/output with or without pull-high resistor by mask option. PA4~PA7 are al ways pull-high NMOS input/output. Of the eight bits, PA0~PA1 can be set as I/O pins or buzzer outputs by mask op tion. PA3 can be set as an I/O pin or as a PFD output also by mask option.

PB0~PB7 constitute an 8-bit Schmitt trigger input port. Each bit on port are pull-high resistor. Of the eight bits, PB0 and PB1 can be set as input pins or as external interrupt control pins (INT0

) and (INT1) respectively, by software application. PB2 and PB3 can be set as an input pin or as a timer/event counter input pin TMR0 and TMR1 also by software application.

PC0~PC3 constitute a 4-bit bidirectional input/output port with a schmitt trigger input capability. On the port, such can be configured as CMOS output or NMOS input/output with or without pull-high resistor by mask option.

Negative power supply, GND

LCD power supply

Voltage pump

SEG32 can be set as a segment or as a common output driver for LCD panel by mask option. COM2~COM0 are outputs for LCD panel plate.

LCD driver outputs for LCD panel segments

Real time clock oscillators

Positive power supply

OSC1 and OSC2 are connected to an RC network or a crystal (by mask option) for the internal system clock. In the case of RC operation, OSC2 is the output terminal for 1/4 system clock.

Schmitt trigger reset input, active low

6 August 18, 1999

Absolute Maximum Ratings

HT49C50

Supply Voltage........................VSS-0.3V to 5.5V

Input Voltage .................V

-0.3V to VDD+0.3V

Storage Temperature.................-50°Cto125°C

Operating Temperature ..............-25°Cto70°C

Note: These are stress ratings only. Stresses exceeding the range specified under ²Absolute Maxi

mum 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 expo sure to extreme conditions may affect device reliability.

D.C. Characteristics

Ta=25°C

Test Conditions

Symbol Parameter

DD1

DD2

STB1

STB2

IL1

IH1

Operating Voltage

Operating Current (Crystal OSC)

Operating Current (RC OSC)

Standby Current (RTC Enable, LCD ON)

Standby Current (RTC Disable, LCD OFF)

I/O Port Input Low Voltage

I/O Port Input High Voltage

Input Low Voltage (RES

, INT0, INT1, TMR0, TMR1)

Input High Voltage (RES

, INT0, INT1, TMR0, TMR1)

I/O Ports Sink Current

Conditions

¾¾

No load, f

=4MHz

SYS

No load,

=2MHz

SYS

No load, system halt

RES

=0.5V

INT0/1=0.3V

5V 0

TMR0/1=0.3V

0.8V

5V 4.0

=3V,

=0.3V

=5V,

=0.5V

Min. Typ. Max. Unit

2.2

12mA

2.5 5 mA

0.75 1.5 mA

1.5 3 mA

¾¾

2.1

3.5

2.4

1.5/0.9 V

2.5/1.5 V

1.5 2.5

5.2 V

0.9 V

1.5 V

7 August 18, 1999

HT49C50

Symbol Parameter

I/O Ports Source Current

Pull-high Resistance of

I/O Ports and INT0

A.C. Characteristics

Symbol Parameter

SYS1

SYS2

TIMER

WDTOSC

RES

SST

INT

System Clock (Crystal OSC)

System Clock (RC OSC)

Timer I/P Frequency

(TMR0/TMR1)

Watchdog Oscillator

External Reset Low Pulse Width

System Start-up Timer Period

Interrupt Pulse Width

, INT1

Test Conditions

Conditions

=3V,

=2.7V

=5V,

=4.5V

Test Conditions

Conditions

=3V

=5V

=3V

=5V

=3V

=5V

=3V

=5V

¾¾

Power-up or

wake-up from halt

¾¾

Min. Typ. Max. Unit

-1 -1.5 ¾

-2 -3 ¾

40 60 80

10 30 50

Ta=25°C

Min. Typ. Max. Unit

455

400

45 90 180

35 65 130

1024

4000 kHz

2000 kHz

3000 kHz

4000 kHz

¾¾ms

SYS

¾¾ms

Note: t

SYS

= 1/f

SYS

8 August 18, 1999

Functional Description

Execution flow

The system clock is derived from either a crys tal or an RC oscillator. It is internally divided into four non-overlapping clocks. One instruc tion cycle consists of four system clock cycles.

Instruction fetching and execution are pipelined in such a way that a fetch takes one instruction cycle while decoding and execution takes the next instruction cycle. The pipelining scheme causes each instruction to effectively execute in a cycle. If an instruction changes the value of the program counter, two cycles are re quired to complete the instruction.

Program counter - PC

The program counter (PC) is of 12 bits wide and controls the sequence in which the instructions stored in the program ROM are executed. The contents of the PC can specify a maximum of 4096 addresses.

After accessing a program memory word to fetch an instruction code, the value of the PC is incremented by one. The PC then points to the memory word containing the next instruction code.

When executing a jump instruction, conditional skip execution, loading a PCL register, a subroutine call, an initial reset, an internal interrupt, an external interrupt, or returning from a subroutine, the PC manipulates the program

transfer by loading the address corresponding to each instruction.

The conditional skip is activated by instruc

tions. Once the condition is met, the next in

struction, fetched during the current

instruction execution, is discarded and a dummy cycle replaces it to get a proper instruc tion; otherwise proceed with the next instruc tion.

The lower byte of the PC (PCL) is a readable and writeable register (06H). Moving data into the PCL performs a short jump. The destina

tion is within 256 locations.

When a control transfer takes place, an addi tional dummy cycle is required.

Program memory - ROM

The program memory (ROM) is used to store the program instructions which are to be exe cuted. It also contains data, table, and inter rupt entries, and is organized into 4096 ´ 15 bits which are addressed by the PC and table pointer.

Certain locations in the ROM are reserved for special usage:

Location 000H Location 000H is reserved for program initial-

ization. After chip reset, the program always begins execution at this location.

HT49C50

S ystem C lock

OSC2 (RC only)

T1 T2 T3 T4 T1 T2 T3 T4 T1 T2 T3 T4

PC PC+1 PC+2

F e tc h IN S T ( P C )

Execute IN S T (P C-1)

F e tc h IN S T ( P C + 1 )

Execute IN S T (P C)

F e tc h IN S T ( P C + 2 )

Execute IN S T (P C+1)

Execution flow

9 August 18, 1999

HT49C50

Location 004H Location 004H is reserved for the external in

terrupt service program. If the INT0

input pin is activated, and the interrupt is enabled, and the stack is not full, the program begins execution at location 004H.

Location 008H Location 008H is reserved for the external in

terrupt service program also. If the INT1 put pin is activated, and the interrupt is

000H

004H

008H

00C H

010H

014H

018H

D evice initialization program

External interrupt 0 subroutine

External interrupt 1 subroutine

Tim er/event counter 0 interrupt subroutine

Tim er/event counter 1 interrupt subroutine

T im e B a s e In te rr u p t

R T C In te rru p t

Program ROM

enabled, and the stack is not full, the program begins execution at location 008H.

Location 00CH

n00H

nFFH

Look-up table (256 w ords)

Location 00CH 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 en abled and the stack is not full, the program begins execution at location 00CH.

Location 010H Location 010H is reserved for the timer/event

counter 1 interrupt service program. If a timer interrupt results from a timer/event

Mode

*11 *10 *9 *8 *7 *6 *5 *4 *3 *2 *1 *0

FFFH

counter 1 overflow, and if the interrupt is en abled and the stack is not full, the program begins execution at location 010H.

Program Counter

Look-up table (256 w ords)

15 bits

N o te : n r a n g e s fro m 0 to F

Program memory

Initial Reset 0 0000000 00 00

External Interrupt 0 0 000000001 00

External Interrupt 1 0 000000010 00

Timer/event counter 0 overflow 0 00000001100

Timer/event counter 1 overflow 0 00000010000

Time Base Interrupt 0 000000101 00

RTC Interrupt 0 000000110 00

Skip PC+2

Loading PCL *11 *10 *9 *8 @7 @6 @5 @4 @3 @2 @1 @0

Jump, Call Branch #11 #10 #9 #8 #7 #6 #5 #4 #3 #2 #1 #0

Return From Subroutine S11 S10 S9 S8 S7 S6 S5 S4 S3 S2 S1 S0

Notes: *11~*0: Program counter bits

#11~#0: Instruction code bits

Program counter

S11~S0: Stack register bits

@7~@0: PCL bits

10 August 18, 1999

Location 014H Location 014H is reserved for the Time Base

interrupt service program. If a Time Base in terrupt occurs, and the interrupt is enabled, and the stack is not full, the program begins execution at location 014H.

Location 018H Location 018H is reserved for the real time

clock interrupt service program. If a real time clock interrupt occurs, and the interrupt is enabled, and the stack is not full, the program begins execution at location 018H.

Table location Any location in the ROM can be used as a

look-up table. The instructions ²TABRDC [m]² (the current page, 1 page=256 words) and ²TABRDL [m]² (the last page) transfer the contents of the lower-order byte to the specified data memory, and the contents of the higher-order byte to TBLH (Table Higher-order byte register) (08H). Only the destination of the lower-order byte in the ta ble is well-defined; the other bits of the table word are all transferred to the lower portion of TBLH, and the remaining 1 bit is read as ²0². The TBLH is read only, and the table pointer (TBLP) is a read/write register (07H), indicating the table location. Before accessing the table, the location should be placed in TBLP. All the table related instructions require 2 cycles to complete the operation. These areas may function as a normal ROM depending upon the user¢s requirements.

Stack register - STACK

The stack register is a special part of the mem

ory used to save the contents of the PC. The

stack is organized into 6 levels and is neither part of the data nor part of the program, and is neither readable nor writeable. Its activated level is indexed by a stack pointer (SP) and is neither readable nor writeable. At a commence ment of a subroutine call or an interrupt ac knowledgment, the contents of the PC is pushed onto the stack. At the end of the subrou tine or interrupt routine, signaled by a return instruction (RET or RETI), the contents of the PC is restored to its previous value from the stack. After chip reset, the SP will point to the top of the stack.

If the stack is full and a non-masked interrupt takes place, the interrupt request flag is re corded but the acknowledgment is still inhib ited. Once the SP is decremented (by RET or RETI), the interrupt is serviced. This feature prevents stack overflow, allowing the program

mer to use the structure easily. Likewise, if the stack is full, and a ²CALL² is subsequently exe cuted, a stack overflow occurs and the first en try is lost (only the most recent six return addresses are stored).

Data memory - RAM

The data memory (RAM) is designed with 192´8 bits, and is divided into two functional groups, namely special function registers and general purpose data memory, most of which are readable/writeable, although some are read only.

HT49C50

Instruction(s)

*11 *10 *9 *8 *7 *6 *5 *4 *3 *2 *1 *0

Table Location

TABRDC [m] P11 P10 P9 P8 @7 @6 @5 @4 @3 @2 @1 @0

TABRDL [m] 1 1 1 1 @7 @6 @5 @4 @3 @2 @1 @0

Table location

Notes: *11~*0: Table location bits

P11~P8: Current program Counter bits

@7~@0: Table pointer bits

11 August 18, 1999

HT49C50

Ind irect A ddressing R egister 0

00H

01H

Ind irect A ddressing R egister 1

02H

03H

04H

05H

06H

07H

08H

09H

0AH

0BH

0C H

0D H

0EH

0FH

10H

11H

12H

13H

14H

15H

16H

17H

18H

19H

1AH

1BH

1C H

1D H

1EH 1FH

60H

FFH

MP0

MP1

ACC

PCL

TBLP

TBLH

RTCC

STATUS

IN T C 0

TM R 0

TM R 0C

TM R 1

TM R 1C

IN T C 1

G eneral P urpose DATA M EMO RY

(160 Bytes)

Special P urpose DATA M EMO RY

: U nused.

R ead as ²00

RAM mapping

Of the two types of functional groups, the special function registers consist of an Indirect address ing register 0 (00H), a Memory pointer register 0 (MP0;01H), an Indirect addressing register 1 (02H), a Memory pointer register 1 (MP1;03H), a Bank pointer (BP;04H), an Accumulator (ACC;05H), a Program counter lower-order byte register (PCL;06H), a Table pointer (TBLP;07H),

a Table higher-order byte register (TBLH;08H), a Real time clock control register (RTCC;09H), a Status register (STATUS;0AH), an Interrupt control register 0 (INTC0;0BH), a timer/event counter 0 (TMR0;0DH), a timer/event counter 0 control register (TMR0C;0EH), a timer/event counter 1 (TMR1;10H), a timer/event counter 1 control register (TMR1C;11H), I/O registers (PA;12H, PB;14H, PC;16H), and Interrupt con trol register 1 (INTC1;1EH). On the other hand, the general purpose data memory, addressed from 60H to FFH, is used for data and control in formation under instruction commands.

The areas in the RAM can directly handle arithmetic, logic, increment, decrement, and rotate operations. Except some dedicated bits, each bit in the RAM can be set and reset by ²SET [m].i²and ²CLR [m].i². They are also indi rectly accessible through the Memory pointer register 0 (MP0;01H) or the Memory pointer register 1 (MP1;03H).

Indirect addressing register

Location 00H and 02H are indirect addressing registers that are not physically implemented. Any read/write operation of [00H] and [02H] accesses the RAM pointed to by MP0 (01H) and MP1(03H) respectively. Reading location 00H or 02H indirectly returns the result 00H. While, writing it indirectly leads to no operation.

The function of data movement between two indirect addressing registers is not supported. The memory pointer registers, MP0 and MP1, are both 8-bit registers used to access the RAM by combining corresponding indirect addressing registers. MP0 can only be applied to data memory, while MP1 can be applied to data memory and LCD display memory.

Accumulator - ACC

The accumulator (ACC) is related to the ALU operations. It is also mapped to location 05H of the RAM and is capable of operating with im mediate data. The data movement between two data memory locations must pass through the ACC.

12 August 18, 1999

HT49C50

Arithmetic and logic unit - ALU

This circuit performs 8-bit arithmetic and logic operations and provides the following func tions:

Arithmetic operations (ADD, ADC, SUB, SBC, DAA)

Logic operations (AND, OR, XOR, CPL)

Rotation (RL, RR, RLC, RRC)

Increment and Decrement (INC, DEC)

Branch decision (SZ, SNZ, SIZ, SDZ etc.)

The ALU not only saves the results of a data op eration but also changes the status register.

Status register - STATUS

The status register (0AH) is of 8 bits wide and contains, a carry flag (C), an auxiliary carry flag (AC), a zero flag (Z), an overflow flag (OV), a power down flag (PD), and a watchdog time-out flag (TO). It also records the status information and controls the operation sequence.

Except the TO and PD flags, bits in the status register can be altered by instructions similar to other registers. Data written into the status register does not alter the TO or PD flags. Oper

ations related to the status register, however, may yield different results from those intended. The TO and PD flags can only be changed by a

watchdog timer overflow, chip power-up, or

clearing the watchdog timer and executing the ²HALT² instruction. The Z, OV, AC, and C flags reflect the status of the latest operations.

On entering the interrupt sequence or execut ing the subroutine call, the status register will not be automatically pushed onto the stack. If the contents of the status is important, and if the subroutine is likely to corrupt the status

tions and save it properly.

Interrupts

The HT49C50 provides two external inter rupts, two internal timer/event counter inter rupts, an internal time base interrupt, and an internal real time clock interrupt. The inter rupt control register 0 (INTC0;0BH) and inter rupt control register 1 (INTC1;1EH) both contain the interrupt control bits that are used to set the enable/disable status and interrupt request flags.

Labels Bits Function

C is set if the operation results in a carry during an addition operation or if a bor-

row does not take place during a subtraction operation; otherwise C is cleared. C is also affected by a rotate through carry instruction.

AC is set if the operation results in a carry out of the low nibbles in addition or no

AC 1

borrow from the high nibble into the low nibble in subtraction; otherwise AC is cleared.

OV 3

PD 4

TO 5

¾ ¾

Z is set if the result of an arithmetic or logic operation is zero; otherwise Z is cleared.

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.

PD is cleared by either a system power-up or executing the ²CLR WDT² instruc tion. PD is set by executing the ²HALT² instruction.

TO is cleared by a system power-up or executing the ²CLR WDT² or ²HALT² in struction. TO is set by a WDT time-out.

Undefined, read as ²0²

Status register

13 August 18, 1999

HT49C50

Once an interrupt subroutine is serviced, other interrupts are all blocked (by clearing the EMI bit). This scheme may prevent any further in terrupt nesting. Other interrupt requests may take place during this interval, but only the in terrupt request flag will be recorded. If a cer tain interrupt requires servicing within the service routine, the EMI bit and the correspond ing bit of the INTC0 or of INTC1 may be set in order to allow interrupt nesting. Once the stack is

Control the master (global) interrupt (1=enabled; 0=disabled)

Control the external interrupt 0 (1=enabled; 0=disabled)

Control the external interrupt 1 (1=enabled; 0=disabled)

Control the timer/event counter 0 interrupt (1=enabled; 0=disabled)

External interrupt 0 request flag (1=active; 0=inactive)

External interrupt 1 request flag (1=active; 0=inactive)

Internal timer/event counter 0 request flag (1=active; 0=inactive)

Control the timer/event counter 1 interrupt (1=enabled; 0=disabled)

Control the time base interrupt (1=enabled; 0:disabled)

Control the real time clock interrupt (1=enabled; 0:disabled)

Internal timer/event counter 1 request flag (1=active; 0=inactive)

Time base request flag (1=active; 0=inactive)

Real time clock request flag (1=active; 0=inactive)

INTC0

(0BH)

INTC1

(1EH)

0 EMI

1 EEI0

2 EEI1

3 ET0I

4 EIF0

5 EIF1

6 T0F

0 ET1I

1 ETBI

2 ERTI

4 T1F

5 TBF

6 RTF

¾ Unused bit, read as ²0²

full, the interrupt request will not be acknowl edged, even if the related interrupt is enabled, until the SP is decremented. If immediate service

is desired, the stack should be prevented from be coming full.

All these interrupts can support a wake-up

function. As an interrupt is serviced, a control

transfer occurs by pushing the contents of the

PC onto the stack followed by a branch to a sub

INTC register

14 August 18, 1999

HT49C50

routine at the specified location in the ROM. Only the contents of the PC is pushed onto the stack. If the contents of the register or of the status register (STATUS) is altered by the in terrupt service program which corrupts the de sired control sequence, the contents should be saved in advance.

External interrupts are triggered by a high to low transition of INT0 interrupt request flag (EIF0; bit 4 of INTC0, EIF1; bit 5 of INTC0) is set as well. After the in terrupt is enabled, the stack is not full, and the external interrupt is active, a subroutine call to location 04H or 08H occurs. The interrupt re quest flag (EIF0 or EIF1) and EMI bits are all cleared to disable other interrupts.

The internal timer/event counter 0 interrupt is initialized by setting the timer/event counter 0 interrupt request flag (T0F; bit 6 of INTC0), which is normally caused by a timer overflow. After the interrupt is enabled, and the stack is not full, and the T0F bit is set, a subroutine call to location 0CH occurs. The related interrupt request flag (T0F) is reset, and the EMI bit is cleared to disable further interrupts. The timer/event counter 1 is operated in the same manner but its related interrupt request flag is T1F (bit 4 of INTC1) and its subroutine call location is 10H.

The time base interrupt is initialized by setting the time base interrupt request flag (TBF; bit 5 of INTC1), that is caused by a regular time base signal. After the interrupt is enabled, and the stack is not full, and the TBF bit is set, a subroutine call to location 14H occurs. The related interrupt request flag (TBF) is reset and the EMI bit is cleared to disable further interrupts.

The real time clock interrupt is initialized by setting the real time clock interrupt request flag (RTF; bit 6 of INTC1), that is caused by a regular real time clock signal. After the inter rupt is enabled, and the stack is not full, and the RTF bit is set, a subroutine call to location 18H occurs. The related interrupt request flag (RTF) is reset and the EMI bit is cleared to dis able further interrupts.

During the execution of an interrupt subroutine, other interrupt acknowledgments are all held

or INT1, and the related

until the ²RETI² instruction is executed or the EMI bit and the related interrupt control bit are set both to 1 (if the stack is not full). To return

from the interrupt subroutine, ²RET² or ²RETI²

may be invoked. RETI sets the EMI bit and en ables an interrupt service, but RET does not.

Interrupts occurring in the interval between the rising edges of two consecutive T2 pulses are serviced on the latter of the two T2 pulses if the corresponding interrupts are enabled. In

the case of simultaneous requests, the priori ties in the following table apply. These can be masked by resetting the EMI bit.

No. Interrupt Source Priority Vector

a External interrupt 0 1 04H

b External interrupt 1 2 08H

Timer/event

counter 0 overflow

Timer/event

counter 1 overflow

Time base

interrupt

Real time clock

interrupt

The timer/event counter 0 interrupt request flag (T0F), external interrupt 1 request flag (EIF1), external interrupt 0 request flag (EIF0), enable timer/event counter 0 interrupt bit (ET0I), enable external interrupt 1 bit (EEI1), enable external interrupt 0 bit (EEI0), and enable master interrupt bit (EMI) make up of the Interrupt Control register 0 (INTC0) which is located at 0BH in the RAM. The real time clock interrupt request flag (RTF), time base interrupt request flag (TBF), timer/event counter 1 interrupt request flag (T1F), enable real time clock interrupt bit (ERTI), and enable time base interrupt bit (ETBI), enable

timer/event counter 1 interrupt bit (ET1I) on the other hand, constitute the Interrupt Con trol register 1 (INTC1) which is located at 1EH in the RAM. EMI, EEI0, EEI1, ET0I, ET1I,

ETBI, and ERTI are all used to control the en able/disable status of interrupts. These bits prevent the requested interrupt from being ser

3 0CH

4 10H

5 14H

6 18H

15 August 18, 1999

HT49C50

viced. Once the interrupt request flags (RTF, TBF, T0F, T1F, EIF1, EIF0) are all set, they re main in the INTC1 or INTC0 respectively until the interrupts are serviced or cleared by a soft ware instruction.

It is recommended that a program not use the ²CALL subroutine² within the interrupt subroutine. It¢s because interrupts often occur in an unpredictable manner or require to be serviced immediately in some applications. At this time, if only one stack is left, and enabling the interrupt is not well con trolled, operation of the ²call² in the interrupt subroutine may damage the original control se quence.

Oscillator configuration

The HT49C50 provides two oscillator circuits for system clocks, i.e., RC oscillator and crystal oscillator, determined by mask option. No mat ter what type of oscillator is selected, the signal is used for the system clock. The HALT mode stops the system oscillator and ignores external signal to conserve power.

Of the two oscillators, if the RC oscillator is used, an external resistor between OSC1 and VSS is required, and the range of the resistance should be from 51kW to 1MW. The system clock, divided by 4, is available on OSC2 with pull-high resistor, which can be used to synchronize external logic. The RC oscillator provides the most cost effective solution. However, the frequency of the oscillation may vary with VDD, temperature, and the chip itself due to process variations. It is therefore, not suitable for timing sensitive operations where accurate oscillator frequency is desired.

OSC1

VDD

On the other hand, if the crystal oscillator is se lected, a crystal across OSC1 and OSC2 is

needed to provide the feedback and phase shift required for the oscillator, and no other exter

nal components are required. A resonator may be connected between OSC1 and OSC2 to re place the crystal and to get a frequency refer ence, but two external capacitors in OSC1 and OSC2 are required.

There is another oscillator circuit designed for the real time clock. In this case, only the

32.768kHz crystal oscillator can be applied. The crystal should be connected between OSC3

and OSC4, and two external capacitors along with one external resistor are required for the oscillator circuit in order to get a stable fre quency.

The RTC oscillator circuit can be controlled to oscillate quickly by setting the ²QOSC² bit (bit

4 of RTCC). It is recommended to turn on the quick oscillating function upon power on, and turn it off after 2 seconds.

OSC3

OSC4

RTC oscillator

The WDT oscillator is a free running on-chip RC oscillator, and no external components are required. Although the system enters the power down mode, the system clock stops, and the WDT oscillator still works with a period of approximately 78ms. The WDT oscillator can be disabled by mask option to conserve power.

OSC2

C rystal O scillator

System oscillator

SYS

OSC2

R C O s c illa to r

16 August 18, 1999

Watchdog timer - WDT

The WDT clock source is implemented by a ded icated RC oscillator (WDT oscillator) or an in struction clock (system clock/4) or a real time clock oscillator (RTC oscillator). The timer is designed to prevent a software malfunction or sequence from jumping to an unknown location with unpredictable results. The WDT can be disabled by mask option. But if the WDT is dis abled, all executions related to the WDT lead to no operation.

After the WDT clock source is selected, the time-out period is f

/215~fS/216.

If the WDT clock source chooses the internal WDT oscillator, the time-out period may vary with temperature, VDD, and process variations. On the other hand, if the clock source selects the instruction clock and the ²halt² instruction is exe cuted, WDT may stop counting and lose its pro tecting purpose, and the logic can only be restarted by an external logic.

When the device operates in a noisy environ ment, using the on-chip RC oscillator (WDT OSC) is strongly recommended, since the HALT can stop the system clock.

The WDT overflow under normal operation initializes a ²chip reset² and sets the status bit ²TO². In the HALT mode, the overflow initializes a ²warm reset², and only the PC and SP are reset to zero. To clear the contents of the WDT, there are three methods to be adopted,

i.e., external reset (a low level to RES

instruction, and a ²HALT² instruction. There

are two types of software instructions; ²CLR WDT² and the other set -²CLR WDT1² and ²CLR WDT2². Of these two types of instruction, only one type of instruction can be active at a time depending on the mask option -²CLR

WDT times selection option².Ifthe²CLR WDT² is selected (i.e., CLR WDT times equal one), any execution of the ²CLR WDT² instruction clears the WDT. In the case that ²CLR WDT1² and ²CLR WDT2² are chosen (i.e., CLR WDT times equal two), these two instructions have to be ex ecuted to clear the WDT; otherwise, the WDT may reset the chip due to time-out.

Multi-function timer

The HT49C50 provides a multi-function timer for

the WDT, time base and RTC but with different

time-out periods. The multi-function timer con sists of a 7-stage divider and an 8-bit prescaler,

with the clock source coming from the WDT OSC

or RTC OSC or the instruction clock (i.e.., system clock divided by 4). The multi-function timer also provides a selectable frequency signal (ranges

/22to fS/28) for LCD driver circuits, and a

from f

selectable frequency signal (ranges from f f

/29) for the buzzer output by mask option. It is

recommended to select a near 4kHz signal to LCD driver circuits for proper display.

HT49C50

), software

/22to

S ystem C lock/4

RTC

32768H z

OSC

WDT

12kHz

OSC

Mask Option Select

D ivider

Prescaler

CK TRCK T

W D T C lear

17 August 18, 1999

Tim e-out R eset

15 16

/2 ~ fS/2

Time base

The time base offers a periodic time-out period to generate a regular internal interrupt. Its time-out period ranges from f

/212to fS/215se

lected by mask option. If time base time-out oc curs, the related interrupt request flag (TBF; bit 5 of INTC1) is set. But if the interrupt is en abled, and the stack is not full, a subroutine call to location 14H occurs. The time base time-out signal also can be applied to be a clock source of timer/event counter 1 for getting a longer timer-out period.

Real time clock - RTC

The real time clock (RTC) is operated in the same manner as the time base that is used to supply a regular internal interrupt. Its time-out period ranges from f

/28to fS/215by

software programming . Writing data to RT2, RT1 and RT0 (bit2, 1, 0 of RTCC;09H) yields various time-out periods. If the RTC time-out occurs, the related interrupt request flag (RTF; bit 6 of INTC1) is set. But if the interrupt is en abled, and the stack is not full, a subroutine call to location 18H occurs. The real time clock time-out signal also can be applied to be a clock source of timer/event counter 0 for getting a longer time-out period.

RT2 RT1 RT0

000 2

001 2

010 2

RTC Clock Divided

Factor

011 2

100 2

101 2

110 2

111 2

Power down operation - HALT

The HALT mode is initialized by the ²HALT² instruction and results in the following.

The system oscillator turns off but the WDT oscillator keeps running (if the WDT oscilla tor or the real time clock is selected).

The contents of the on-chip RAM and of the registers remain unchanged.

The WDT is cleared and start recounting (if the WDT clock source is from the WDT oscillator or the real time clock oscillator).

HT49C50

D ivider

L C D D riv e r (fS/2 ~ fS/2 )

B uzzer (f

Mask Option

/2 ~ fS/2 )

Prescaler

Mask

Option

T im e B a s e In te rru p t

(fS/2 ~ fS/2 )

Time base

D ivider

RT2 RT1 RT0

P re scale r

8 to 1

Mux.

fS/2 ~ fS/2 RTC Interrupt

Real time clock

18 August 18, 1999

HT49C50

All I/O ports maintain their original status.

The PD flag is set but the TO flag is cleared.

LCD driver is still running (if the WDT OSC or RTC OSC is selected).

The system quits the HALT mode by an external reset, an interrupt, an external falling edge sig nal on port A, or a WDT overflow. An external re set causes device initialization, and the WDT overflow performs a ²warm reset². After examin ing the TO and PD flags, the reason for chip re set can be determined. The PD flag is cleared by system power-up or by executing the ²CLR WDT² instruction, and is set by executing the ²HALT² instruction. On the other hand, the TO flag is set if WDT time-out occurs, and causes a wake-up that only resets the PC (Program Counter) and SP, and leaves the others at their original state.

The port A wake-up and interrupt methods can be considered as a continuation of normal exe cution. Each bit in port A can be independently selected to wake up the device by mask option. Awakening from an I/O port stimulus, the pro gram resumes execution of the next instruc tion. On the other hand, awakening from an interrupt, two sequences may occur. If the related interrupt is disabled or the interrupt is enabled but the stack is full, the program resumes execution at the next instruction. But if the interrupt is enabled, and the stack is not full, the regular interrupt response takes place.

When an interrupt request flag is set before entering the ²halt² status, the system cannot be awaken using that interrupt.

If wake-up events occur, it takes 1024 t

SYS

(sys tem clock period) to resume normal operation. In other words, a dummy period is inserted af ter the wake-up. If the wake-up results from an interrupt acknowledgment, the actual inter rupt subroutine execution is delayed by more than one cycle. However, if the Wake-up results in the next instruction execution, the execution will be performed immediately after the dummy period is finished.

To minimize power consumption, all the I/O pins should be carefully managed before enter ing the HALT status.

Reset

There are three ways in which reset may occur.

RES is reset during normal operation

RES is reset during HALT

WDT time-out is reset during normal operation

The WDT time-out during HALT differs from other chip reset conditions, for it can perform a ²warm reset² that resets only the PC and SP and leaves the other circuits at their original state. Some registers remain unaffected during any other reset conditions. Most registers are reset to the ²initial condition² once the reset conditions are met. Examining the PD and TO flags, the program can distinguish between dif ferent ²chip resets².

VDD

RES

Reset circuit

TO PD RESET Conditions

0 0 RES

0 1 RES

reset during power-up

reset during normal

RES operation

Wake-up HALT

WDT time-out during normal operation

1 1 WDT Wake-up HALT

Note:

²u² means ²unchanged²

19 August 18, 1999

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 awakes from the HALT state or during power up. Awaking from the HALT state or system power-up, the SST delay is added.

An extra SST delay is added during the power-up period, and any wake-up from the HALT may enable only the SST delay.

The functional unit chip reset status is shown below.

PC 000H

Interrupt Disabled

Prescaler, Divider Cleared

WDT, RTC, Time base

Timer/event counter

Cleared. After master reset, WDT starts counting

Off

Input/output ports Input mode

Points to the top of the stack

VDD

RES

SST Tim e-out

Chip Reset

HALT

WDT

RES

OSC1

10-bit R ipple

Power-on D etection

Reset timing chart

WDT Tim e-out

Reset

External

SST

C ounter

Reset configuration

HT49C50

SST

W arm R eset

Cold Reset

20 August 18, 1999

HT49C50

The states of the registers are summarized below:

WDT

TMR0 xxxx xxxx uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu

TMR0C 0000 1--- 0000 1--- 0000 1--- 0000 1--- uuuu u---

TMR1 xxxx xxxx uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu

TMR1C 0000 1--- 0000 1--- 0000 1--- 0000 1--- uuuu u---

Program Counter 000H 000H 000H 000H 000H

MP0 xxxx xxxx uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu

MP1 xxxx xxxx uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu

ACC xxxx xxxx uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu

TBLP xxxx xxxx uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu

TBLH -xxx xxxx -uuu uuuu -uuu uuuu -uuu uuuu -uuu uuuu

STATUS --00 xxxx --1u uuuu --uu uuuu --01 uuuu --11 uuuu

INTC0 -000 0000 -000 0000 -000 0000 -000 0000 -uuu uuuu

INTC1 -000 -000 -000 -000 -000 -000 -000 -000 -uuu -uuu

RTCC --00 0111 --00 0111 --00 0111 --00 0111 --uu uuuu

PA 1111 1111 1111 1111 1111 1111 1111 1111 uuuu uuuu

PB 1111 1111 1111 1111 1111 1111 1111 1111 uuuu uuuu

PC ---- 1111 ---- 1111 ---- 1111 ---- 1111 ---- uuuu

Reset

(Power On)

Time-out

(Normal

Operation)

Reset

RES

(Normal

Operation)

RES

(HALT)

Reset

WDT

Time-out

(HALT)*

Notes:

²*² refers to warm reset ²u² means unchanged ²x² means unknown

21 August 18, 1999

HT49C50

Timer/event counter

Two timer/event counters are implemented in the HT49C50. Both of them contain an 8-bit programmable count-up counter.

The timer/event count 0 clock source may come from the system clock or system clock/4 or RTC time-out signal or external source. System clock source or system clock/4 is selected by mask option.

The timer/event count 1 clock source may come from TMR0 overflow or system clock or time base time-out signal or system clock/4 or exter nal source, and the three former clock source is selected by mask option.

The external clock input allows the user to count external events, measure time intervals or pulse widths, or to generate an accurate time base.

The two timer/event counters are operated al most in the same manner, except the clock source and related registers.

There are two registers related to the timer/event counter 0, i.e., TMR0 ([0DH]) and TMR0C ([0EH]), and two registers related to the timer/event counter 1, i.e., TMR1 ([10H], and TMR1C ([11H]). There are also two physical registers are mapped to TMR0 (TMR1) location; writing TMR0 (TMR1) places the starting value in the timer/event counter preload register, while reading it yields the contents of the timer/event counter. TMR0C and TMR1C are

timer/event counter control registers used to define some options.

The TN0 and TN1 bits define the operation mode. The event count mode is used to count ex ternal events, which means that the clock source is from an external (TMR0, TMR1) pin. The timer mode functions as a normal timer with the clock source coming from the internal selected clock source. Finally, the pulse width measurement mode can be used to count the high or low level duration of the external signal (TMR0, TMR1), and the counting is based on

the internal selected clock source.

In the event count or timer mode, the timer/event counter starts counting at the current contents in the timer/event counter and ends at FFH. Once an overflow occurs, the counter is reloaded from the timer/event counter preload register, and generates an interrupt request flag (T0F; bit 6 of INTC0, T1F; bit 4 of INTC1).

In the pulse width measurement mode with the values of the TON and TE bits equal to one, after the TMR0 (TMR1) has received a transient from low to high (or high to low if the TE bit is ²0²), it will start counting until the TMR0 (TMR1) returns to the original level and resets the TON. The measured result remains in the timer/event counter even if the activated transient occurs again. In other words, only one cycle measurement can be made until the TON is set. The cycle measurement will re-function as long as it receives

System C lock

S y s te m C lo c k /4

RTC O ut

Mask Option Select

TN2

TM R 0

TN1 TN0

TO N

M U X

TN1 TN0

Pulse W idth M easurem ent M ode C ontrol

Timer/event counter 0

D ata bus

Tim er/event counter 0

Preload R egister

Tim er/event

counter 0

PA3 Data CTRL

22 August 18, 1999

R eload

O verflow T o In te r ru p t

PFD0

HT49C50

Label

(TMR0C)

TE 3

TON 4

TN2 5

Bits Function

0~2

Unused bits, read as ²0²

To define the TMR0 active edge of timer/event counter (0=active on low to high; 1=active on high to low)

To enable/disable timer counting (0=disabled; 1=enabled)

2 to 1 multiplexer control inputs to select the timer/event counter clock source (0=RTC outputs; 1= system clock or system clock/4)

To define the operating mode (TN1, TN0)

TN0 TN1

01= Event count mode (External clock)

10= Timer mode (Internal clock)

11= Pulse Width measurement mode (External clock) 00= Unused

TMR0C register

further transient pulse. In this operation mode, the timer/event counter begins counting accord ing not to the logic level but to the transient edges. In the case of counter overflows, the coun ter is reloaded from the timer/event counter preload register and issues an interrupt request, as in the other two modes, i.e., event and timer modes.

To enable the counting operation, the Timer ON bit (TON; bit 4 of TMR0C or TMR1C) should be set to 1. In the pulse width measurement mode, the TON is automatically cleared after the measurement cycle is completed. But in the other two modes, the TON can only be reset by

instructions. The overflow of the timer/event counter 0/1 is one of the wake-up sources and

can also be applied to a PFD (Programmable Frequency Divider) output at PA3 by mask op

tion. Only one PFD (PFD0 or PFD1) can be ap plied to PA3 by mask option . No matter what the operation mode is, writinga0toET0I or ET1I disables the related interrupt service. When the PFD function is selected, executing ²CLR [PA].3² instruction to enable PFD output and executing ²SET [PA].3² instruction to disable PFD output.

In the case of timer/event counter OFF condition, writing data to the timer/event counter preload register also reloads that data to the

TM R 0 O verflow

S ystem C lock

Tim e B ase O ut

S y s te m C lo c k /4

Mask Option Select

TN2

TM R 1

TN1 TN0

TO N

M U X

TN1 TN0

Pulse W idth M easurem ent M ode C ontrol

Timer/event counter 1

D ata bus

Tim er/event counter 1

Preload R egister

Tim er/event

counter 1

PA3 Data CTRL

23 August 18, 1999

R eload

O verflow T o In te r ru p t

PFD1

HT49C50

Label

(TMR1C)

TE 3

TON 4

TN2 5

TN1 TN0

timer/ event counter. But if the timer/event counter is turn on, data written to the timer/event counter is kept only in the timer/event counter preload register. The timer/event counter still continues its opera tion until an overflow occurs.

When the timer/event counter (reading TMR0/TMR1) is read, the clock is blocked to avoid errors. As this may results in a counting error, blocking of the clock should be taken into account by the programmer.

It is strongly recommended to load a desired value into the TMR0/TMR1 register first, then turn on the related timer/event counter for proper operation. Because the initial value of TMR0/TMR1 is unknown.

Due to the timer/event scheme, the programmer should pay special attention on the instruc tion to enable then disable the timer for the first time, whenever there is a need to use the timer/event function, to avoid unpredicatable result. After this procedure, the timer/event function can be operated normally. The exam ple given below, using two 8-bit width Timer¢s (timer 0 ;timer 1) cascade into 16-bit width.

Bits Function

0~2

Unused bits, read as ²0²

To define the TMR1 active edge of timer/event counter (0= active on low to high; 1= active on high to low)

To enable/disable timer counting (0= disabled; 1= enabled)

2 to 1 multiplexer control inputs to select the timer/event counter clock source (0= mask option clock source; 1= system clock/4)

To define the operating mode 01= Event count mode (External clock)

10= Timer mode (Internal clock)

11= Pulse Width measurement mode (External clock) 00= Unused

TMR1C register

START:

mov a, 09h ; Set ET0I&EMI bits to mov intc0, a ; enable timer 0 and

mov a, 01h ; Set ET1I bit to enable

mov intc1, a ; timer 1 interrupt

mov a, 80h ; Set operating mode as mov tmr1c, a ; timer mode and select mask

mov a, 0a0h ; Setoperating mode astimer mov tmr0c, a ; mode and select system

set tmr1c.4 ; Enable then disable timer 1 clr tmr1c.4 ; for the first time

mov a, 00h ; Load a desired value into

mov tmr0, a ; the TMR0/TMR1 register mov a, 00h ; mov tmr1, a ;

set tmr0c.4 ; Normal operating set tmr1c.4 ;

; global interrupt

; option clock source

; clock/4

END

24 August 18, 1999

Input/output ports

There are a 12-bit bidirectional input/output port, an 8-bit input port intheHT49C50,labeled PA, PB and PC which are mapped to [12H], [14H] and [16H] of the RAM, respectively. PA0~PA3 can be configured as CMOS (output) or NMOS (input/output) with or without pull-high resistor by mask option. PA4~PA7 are always pull-high and NMOS (input/output).Ifyou choose NMOS (input), each bit on the port (PA0~PA7) can be configured as a wake-up input. PB can only be used for input operation, and each bit on theport can be configured with pull-high re sistor. PC can be configured as CMOS output or NMOS input/output with or without pull-high re sistor by maskoption. All the port forthe input op eration (PA, PB and PC), these ports are non-latched, that is, the inputs should be ready at the T2 rising edge of the instruction ²MOV A, [m]² (m=12H or 14H). For PA, PC output operation, all data are latched and remain unchanged until the outputlatch is rewritten.

D ata bus

Write

C hip R eset

When the PA and PC structures are open drain NMOS type, it should be noted that, before reading data from the pads, a ²1² should be written to the related bits to disable the NMOS device. That is executing first the instruction ²SET [m].i² (i=0~7 for PA) to disable related NMOS device, and then ²MOV A, [m]² to get stable data.

After chip reset, these input lines remain at the high level or are left floating (by mask option). Each bit of these output latches can be set or

cleared by the ²SET [m].i² and ²CLR [m].i² (m=12H or 16H) instructions.

Some instructions first input data and then fol

low the output operations. For example, ²SET [m].i², ²CLR [m].i², ²CPL [m]², 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 to the ac cumulator.

VDD

Mask option

(P A 0 ~ PA3, PC )

W eak Pull-up

M ask o ption (P A 0 ~ P A 3 , P C )

PA0~PA7 PB0~PB7 PC0~PC3

HT49C50

R ead I/O

System W ake-up (P A only)

M ask o ption

Input/output ports

25 August 18, 1999

LCD display memory

The HT49C50 provides an area of embedded data memory for LCD display. This area is lo cated from 40H to 60H of the RAM at Bank 1. Bank pointer (BP; located at 04H of the RAM) is the switch between the RAM and the LCD dis play memory. When the BP is set as ²1², any data written into 40H~60H will effect the LCD display. When the BP is cleared to ²0², any data written into 40H~60H means to access the gen eral purpose data memory. The LCD display

41H 42H 43H 5E H 5F H 60H B it

COM

40H

memory can be read and written to only by indi rect addressing mode using MP1. When data is

written into the display data area, it is auto matically read by the LCD driver which then generates the corresponding LCD driving sig

nals. To turn the display on or off, a ²1² or a ²0² is written to the corresponding bit of the display memory, respectively. The figure illustrates the mapping between the display memory and LCD

pattern for the HT49C50.

HT49C50

SEG MENT

0 1 2 3 30 31 32

Display memory

26 August 18, 1999

HT49C50

LCD driver output

The output number of the HT49C50 LCD driver can be 33´2or33´3or32´4 by mask option (i.e., 1/2 duty or 1/3 duty or 1/4 duty). The bias type of LCD driver can be ²R² type or ²C² type. If the ²R² bias type is selected, no external capacitor is re quired. If the ²C² bias type is selected, a capacitor mounted between C1 and C2 pins is needed. The bias voltage of LCD driver can be 1/2 bias or 1/3 bias by mask option. If 1/2 bias is selected, a ca pacitor mounted between V2 pin and ground is required. If 1/3 bias is selected, two capacitors are needed for V1 and V2 pins. Refer to application diagram.

D urin g a R eset Pulse:

COM 0,COM 1,CO M2

All LC D driver outputs

N o rm a l O p e r a tio n M o d e :

COM 0

COM 1

COM 2

LC D segm ents on C O M 0,1,2 sides being unlit

O nly LC D segm ents on C O M 0 side being lit

O nly LC D segm ents on C O M 1 side being lit

O nly LC D segm ents on C O M 2 side being lit

LC D segm ents on C O M 0,1 sides being lit

LC D segm ents on C O M 0,2 sides being lit

LC D segm ents on C O M 1,2 sides being lit

LC D segm ents on

C O M 0,1,2 sides being lit

H a lt M o d e :

COM 0,COM 1,CO M2

All LC D driver outputs

Buzzer

HT49C50 provides a pair of buzzer output BZ and BZ

, which share pins with PA0 and PA1 re spectively, ad determined by mask option. Its output frequency can be selected by mask op tion.

When the buzzer function is selected, setting the PA.0 and PA.1 ²0² simultaneously, will en ables the buzzer output and sets the PA.0 ²1² to

disable the buzzer output.

VLCD 1/2 V LCD VSS

VLCD 1/2 V LCD VSS VLCD 1/2 V LCD VSS

VLCD 1/2 V LCD VSS VLCD 1/2 V LCD VSS VLCD 1/2 V LCD VSS VLCD 1/2 V LCD VSS VLCD 1/2 V LCD VSS VLCD 1/2 V LCD VSS VLCD 1/2 V LCD VSS VLCD 1/2 V LCD VSS VLCD 1/2 V LCD VSS

VLCD 1/2 V LCD VSS VLCD 1/2 V LCD VSS

LCD driver output (1/3 duty, 1/2 bias, R/C type)

27 August 18, 1999

3/2 V LC D

VLCD

HT49C50

COM 0

COM 1

COM 2

COM 3

LC D segm ents O N C O M 2 side lighted

1/2 V LC D

VSS

3/2 V LC D

VLCD

1/2 V LC D

VSS

3/2 V LC D

VLCD

1/2 V LC D

VSS

3/2 V LC D

VLCD

1/2 V LC D

VSS

3/2 V LC D

VLCD

1/2 V LC D

VSS

LCD driver output (1/4 duty, 1/3 bias, C type)

28 August 18, 1999

RTCC

(09H)

RT0

0~2

RT1

R/W 0

RT2

¾¾¾Unused bits, this bit must dear to ²0²

4 QOSC R/W 0

8 to 1 multiplexer control inputs to select the real time clock prescaler output

Control the RTC OSC to oscillate quickly

²0² enable ²1² disable

5~7

¾¾¾Unused bits, read as ²0²

RTCC register

Mask option

The following shows 18 kinds of mask options in the HT49C50. All these options should be de

fined in order to ensure proper system function

ing.

No. Mask Option

OSC type selection. This option is to decide if an RC or Crystal oscillator is chosen as sys

tem clock.

WDT Clock source selection. RTC and Time Base. There are three types of selection: sys

tem clock/4 or RTC OSC or WDT OSC.

3 WDT enable/disable selection. WDT can be enabled or disabled by mask option.

CLR WDT times selection. This option defines how to clear the WDT by instruction. ²One

time² means that the ²CLR WDT² can clear the WDT. ²Two times² means only if both of the ²CLR WDT1² and ²CLR WDT2² have been executed, the WDT can be cleared.

Time Base time-out period selection. The Time Base time-out period ranges from

clock/2

uzzer output frequency selection. There are eight types of frequency signals for buzzer output: Clock/2

to clock/215. ²Clock² means the clock source selected by mask option.

~Clock/29. ²Clock² means the clock source selected by mask option.

Wake-up selection. This option defines the wake-up capability. External I/O pins (PA only) all have the capability to wake-up the chip from a HALT by a falling edge.

Pull-high selection. This option is to decide whether the pull-high resistance is visible or not on the PA0~PA3 and PC. (PB and PA4~PA7 are always pull-high)

PA0~PA3 and PC CMOS or NMOS selection. The structure of PA0~PA3 and PC each 4 bits can be selected as CMOS or NMOS individ

ually. When the CMOS is selected, the related pins only can be used for output opera tions. When the NMOS is selected, the related pins can be used for input or output operations. (PA4~PA7 are always NMOS)

HT49C50

29 August 18, 1999

No. Mask Option

Clock source selection of timer/event counter 0. There are two types of selection: system

clock or system clock/4.

Clock source selection of timer/event counter 1. There are three types of selection: TMR0

overflow, system clock or Time Base overflow.

I/O pins share with other functions selection.

PA0/BZ, PA1/BZ: PA0 and PA1 can be set as I/O pins or buzzer outputs. PA3/PFD: PA3 can be set as I/O pins or PFD output.

LCD common selection. There are three types of selection: 2 common (1/2 duty) or 3 com mon (1/3 duty) or 4 common (1/4 duty). If the 4 common is selected, the segment output

pin ²SEG32² will be set as a common output.

LCD bias power supply selection.

There are two types of selection: 1/2 bias or 1/3 bias.

LCD bias type selection.

This option is to decide what kind of bias is selected, R type or C type.

LCD driver clock selection. There are seven types of frequency signals for the LCD driver

circuits: f

/22~fS/28. ²fS² means the clock source selection by mask option.

PFD selection. If PA3 is set as PFD output, there are two types of selection; One is PFD0 as the PFD out

put, the other is PFD1 as the PFD output. PFD0, PFD1 are the timer overflow signals of the timer/event counter 0, timer/event counter 1 respectively.

HT49C50

30 August 18, 1999

Application Circuits

R C o s c illa t o r a p p lic a t io n C ry s t a l o s c illa to r a p p lic a t io n

HT49C50

VDD

OSC1

OSC2

RES

OSC3

OSC4

IN T 0

IN T 1

TM R 0

TM R 1

SEG0~31

HT49C50

PA0~PA7

PB0~PB7

PC0~PC3

COM 0~3

VLCD

LCD

PANEL

LCD Power Supply

0.1mF

OSC1

VDD

SYS

OSC2

VDD

RES

OSC3

OSC4

IN T 0

IN T 1

TM R 0

TM R 1

SEG0~31

HT49C50

PA0~PA7

PB0~PB7

PC0~PC3

COM 0~3

VLCD

LCD

PANEL

LCD Power Supply

0.1mF

31 August 18, 1999

HT49C50

Instruction Set Summary

Mnemonic Description Flag Affected

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]

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]

Increment

and

Decrement

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 register with carry Subtract immediate data from 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 with result in data memory Decimal adjust ACC for addition with result in data memory

AND data memory to ACC OR data memory to ACC Exclusive-OR data memory to ACC AND ACC to data memory OR ACC to data memory Exclusive-OR ACC to data memory AND immediate data to ACC OR immediate data to ACC Exclusive-OR immediate data to ACC Complement data memory Complement data memory with result in ACC

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

Z Z Z Z Z Z Z Z Z Z Z

INCA [m] INC [m] DECA [m] DEC [m]

Increment data memory with result in ACC Increment data memory Decrement data memory with result in ACC Decrement data memory

32 August 18, 1999

Z Z Z Z

HT49C50

Mnemonic Description Flag Affected

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

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

Move data memory to ACC Move ACC to data memory Move immediate data to ACC

Clear bit of data memory Set bit of data memory

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

None None

C None None

None**

None None

None None None None None None None None None None None None None

Table Read

TABRDC [m] TABRDL [m]

Read ROM code (current page) to data memory and TBLH Read ROM code (last page) to data memory and TBLH

33 August 18, 1999

None None

HT49C50

Mnemonic Description Flag Affected

Miscellaneous

NOP CLR [m] SET [m] CLR WDT CLR WDT1 CLR WDT2 SWAP [m] SWAPA [m] HALT

Notes: x: 8-bit immediate data

m: 7-bit data memory address

A: accumulator

i: 0~7 number of bits

addr: 10-bit program memory address

Ö: Flag(s) is affected

-: Flag(s) is not affected

*: Flag(s) may be affected by the execution status

**: For the old version of the E.V. chip, the zero flag (Z) can be affected by executing the

MOV A,[M] instruction. For the new version of the E.V. chip, the zero flag cannot be changed by executing the MOV A,[M] instruction.

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

None None None

TO,PD TO*,PD* TO*,PD*

None None

TO,PD

34 August 18, 1999

HT49C50

Instruction Definition

ADC A,[m] Add data memory and carry to the accumulator

Description The contents of the specified data memory, accumulator and the carry flag

are added simultaneously, leaving the result in the accumulator.

Operation

Affected flag(s)

ADCM A,[m] Add the accumulator and carry to data memory

Description The contents of the specified data memory, accumulator and the carry flag

Operation

Affected flag(s)

ADD A,[m] Add data memory to the accumulator

Description The contents of the specified data memory and the accumulator are added.

Operation

Affected flag(s)

ACC ¬ ACC+[m]+C

TC2 TC1 TO PD OV Z AC C

¾¾¾¾ÖÖÖÖ

are added simultaneously, leaving the result in the specified data memory. [m] ¬ ACC+[m]+C

TC2 TC1 TO PD OV Z AC C

¾¾¾¾ÖÖÖÖ

The result is stored in the accumulator. ACC ¬ ACC+[m]

TC2 TC1 TO PD OV Z AC C

¾¾¾¾ÖÖÖÖ

ADD A,x Add immediate data to the accumulator

Description The contents of the accumulator and the specified data are added, leaving

the result in the accumulator.

Operation

Affected flag(s)

ACC ¬ ACC+x

TC2 TC1 TO PD OV Z AC C

¾¾¾¾ÖÖÖÖ

35 August 18, 1999

HT49C50

ADDM A,[m] Add the accumulator to the data memory

Description The contents of the specified data memory and the accumulator are added.

The result is stored in the data memory.

Operation

Affected flag(s)

AND A,[m] Logical AND accumulator with data memory

Description Data in the accumulator and the specified data memory perform a bitwise

Operation

Affected flag(s)

AND A,x Logical AND immediate data to the accumulator

Description Data in the accumulator and the specified data perform a bitwise logi

Operation

Affected flag(s)

[m] ¬ ACC+[m]

TC2 TC1 TO PD OV Z AC C

¾¾¾¾ÖÖÖÖ

logical_AND operation. The result is stored in the accumulator. ACC ¬ ACC ²AND² [m]

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾Ö¾¾

cal_AND operation. The result is stored in the accumulator. ACC ¬ ACC ²AND² x

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾Ö¾¾

ANDM A,[m] Logical AND data memory with the accumulator

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

Affected flag(s)

[m] ¬ ACC ²AND² [m]

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾Ö¾¾

36 August 18, 1999

HT49C50

CALL addr Subroutine call

Description The instruction unconditionally calls a subroutine located at the indicated

address. The program counter increments once to obtain the address of the next instruction, and pushes this onto the stack. The indicated address is then loaded. Program execution continues with the instruction at this ad dress.

Operation

Affected flag(s)

CLR [m] Clear data memory

Description The contents of the specified data memory are cleared to zero.

Operation

Affected flag(s)

CLR [m].i Clear bit of data memory

Description The bit i of the specified data memory is cleared to zero.

Operation

Affected flag(s)

Stack ¬ PC+1 PC ¬ addr

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

[m] ¬ 00H

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

[m].i ¬ 0

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

CLR WDT Clear watchdog timer

Description The WDT is cleared (re-counting from zero). The power down bit (PD) and

time-out bit (TO) are cleared.

Operation

Affected flag(s)

WDT ¬ 00H PD and TO ¬ 0

TC2 TC1 TO PD OV Z AC C

¾¾

37 August 18, 1999

¾¾¾¾

HT49C50

CLR WDT1 Preclear watchdog timer

Description The TD, PD flags and WDT are all cleared (re-counting from zero), if the

other preclear WDT instruction has been executed. Only execution of this in struction without the other preclear instruction sets the indicated flag which implies that this instruction has been executed and the TO and PD flags re main unchanged.

Operation

Affected flag(s)

CLR WDT2 Preclear watchdog timer

Description The TO, PD flags and WDT are all cleared (re-counting from zero), if the

Operation

Affected flag(s)

WDT ¬ 00H* PD and TO ¬ 0*

TC2 TC1 TO PD OV Z AC C

¾¾

WDT ¬ 00H* PD and TO ¬ 0*

TC2 TC1 TO PD OV Z AC C

¾¾

0* 0*

¾¾¾¾

CPL [m] Complement data memory

Description

Operation

Affected flag(s)

Each bit of the specified data memory is logically complemented (1¢s complement). Bits which previously contained a one are changed to zero and vice-versa.

[m] ¬ [m

TC2 TC1 TO PD OV Z AC C

]

¾¾¾¾¾Ö¾¾

38 August 18, 1999

HT49C50

CPLA [m] Complement data memory and place result in the accumulator

Description

Operation

Affected flag(s)

DAA [m] Decimal-Adjust accumulator for addition

Description The accumulator value is adjusted to the BCD (Binary Code Decimal) code.

Operation If ACC.3~ACC.0 >9 or AC=1

Affected flag(s)

Each bit of the specified data memory is logically complemented (1¢s comple ment). Bits which previously contained a one are changed to zero and vice-versa. The complemented result is stored in the accumulator and the contents of the data memory remain unchanged.

ACC ¬ [m

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾Ö¾¾

The accumulator is divided into two nibbles. Each nibble is adjusted to the BCD code and an internal carry (AC1) will be done if the low nibble of the ac cumulator is greater than 9. The BCD adjustment is done by adding 6 to the original value if the original value is greater than 9 or a carry (AC or C) is set; otherwise the original value remains unchanged. The result is stored in the data memory and only the carry flag (C) may be affected.

then [m].3~[m].0 ¬ (ACC.3~ACC.0)+6, AC1=AC else [m].3~[m].0) ¬ (ACC.3~ACC.0), AC1=0 and If ACC.7~ACC.4+AC1 >9 or C=1 then [m].7~[m].4 ¬ ACC.7~ACC.4+6+AC1,C=1 else [m].7~[m].4 ¬ ACC.7~ACC.4+AC1,C=C

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾ Ö

]

DEC [m] Decrement data memory

Description Data in the specified data memory is decremented by one.

Operation

Affected flag(s)

[m] ¬ [m]-1

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾Ö¾¾

39 August 18, 1999

HT49C50

DECA [m] Decrement data memory and place result in the accumulator

Description Data in the specified data memory is decremented by one, leaving the result

in the accumulator. The contents of the data memory remain unchanged.

Operation

Affected flag(s)

HALT Enter power down mode

Description This instruction stops program execution and turns off the system clock. The

Operation

Affected flag(s)

ACC ¬ [m]-1

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾Ö¾¾

contents of the RAM and registers are retained. The WDT and prescaler are cleared. The power down bit (PD) is set and the WDT time-out bit (TO) is cleared.

PC ¬ PC+1 PD ¬ 1 TO ¬ 0

TC2 TC1 TO PD OV Z AC C

¾¾

¾¾¾¾

INC [m] Increment data memory

Description Data in the specified data memory is incremented by one.

Operation

Affected flag(s)

INCA [m] Increment data memory and place result in the accumulator

Description Data in the specified data memory is incremented by one, leaving the result

Operation

Affected flag(s)

[m] ¬ [m]+1

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾Ö¾¾

in the accumulator. The contents of the data memory remain unchanged. ACC ¬ [m]+1

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾Ö¾¾

40 August 18, 1999

HT49C50

JMP addr Directly jump

Description The contents of the program counter are replaced with the directly-specified

address unconditionally, and control is passed to this destination.

Operation

Affected flag(s)

MOV A,[m] Move data memory to the accumulator

Description The contents of the specified data memory are copied to the accumulator.

Operation

Affected flag(s)

MOV A,x Move immediate data to the accumulator

Description The 8-bit data specified by the code is loaded into the accumulator.

Operation

Affected flag(s)

PC ¬ addr

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

ACC ¬ [m]

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

ACC ¬ x

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

MOV [m],A Move the accumulator to data memory

Description The contents of the accumulator are copied to the specified data memory (one

of the data memories).

Operation

Affected flag(s)

NOP No operation

Description No operation is performed. Execution continues with the next instruction.

Operation

Affected flag(s)

[m] ¬ ACC

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

PC ¬ PC+1

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

41 August 18, 1999

HT49C50

OR A,[m] Logical OR accumulator with data memory

Description Data in the accumulator and the specified data memory (one of the data

memories) perform a bitwise logical_OR operation. The result is stored in the accumulator.

Operation

Affected flag(s)

OR A,x Logical OR immediate data to the accumulator

Description Data in the accumulator and the specified data perform a bitwise logical_OR

Operation

Affected flag(s)

ORM A,[m] Logical OR data memory with the accumulator

Description Data in the data memory (one of the data memories) and the accumulator

Operation

Affected flag(s)

ACC ¬ ACC ²OR² [m]

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾Ö¾¾

operation. The result is stored in the accumulator. ACC ¬ ACC ²OR² x

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾Ö¾¾

perform a bitwise logical_OR operation. The result is stored in the data memory.

[m] ¬ ACC ²OR² [m]

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾Ö¾¾

RET Return from subroutine

Description The program counter is restored from the stack. This is a two-cycle instruc-

tion.

Operation

Affected flag(s)

PC ¬ Stack

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

42 August 18, 1999

HT49C50

RET A,x Return and place immediate data in the accumulator

Description The program counter is restored from the stack and the accumulator loaded

with the specified 8-bit immediate data.

Operation

Affected flag(s)

RETI Return from interrupt

Description The program counter is restored from the stack, and interrupts are enabled

Operation

Affected flag(s)

RL [m] Rotate data memory left

Description The contents of the specified data memory are rotated one bit left with bit 7

Operation

Affected flag(s)

PC ¬ Stack ACC ¬ x

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

by setting the EMI bit. EMI is the enable master (global) interrupt bit (bit 0; register INTC).

PC ¬ Stack EMI ¬ 1

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

rotated into bit 0. [m].(i+1) ¬ [m].i; [m].i:bit i of the data memory (i=0~6)

[m].0 ¬ [m].7

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

RLA [m] Rotate data memory left and place result in the accumulator

Description Data in the specified data memory is rotated one bit left with bit 7 rotated

into bit 0, leaving the rotated result in the accumulator. The contents of the data memory remain unchanged.

Operation

Affected flag(s)

ACC.(i+1) ¬ [m].i; [m].i:bit i of the data memory (i=0~6) ACC.0 ¬ [m].7

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

43 August 18, 1999

HT49C50

RLC [m] Rotate data memory left through carry

Description The contents of the specified data memory and the carry flag are rotated one

bit left. Bit 7 replaces the carry bit; the original carry flag is rotated into the bit 0 position.

Operation

Affected flag(s)

RLCA [m] Rotate left through carry and place result in the accumulator

Description Data in the specified data memory and the carry flag are rotated one bit left.

Operation

Affected flag(s)

[m].(i+1) ¬ [m].i; [m].i:bit i of the data memory (i=0~6) [m].0 ¬ C C ¬ [m].7

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾ Ö

Bit 7 replaces the carry bit and the original carry flag is rotated into bit 0 po sition. The rotated result is stored in the accumulator but the contents of the data memory remain unchanged.

ACC.(i+1) ¬ [m].i; [m].i:bit i of the data memory (i=0~6) ACC.0 ¬ C C ¬ [m].7

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾ Ö

RR [m] Rotate data memory right

Description The contents of the specified data memory are rotated one bit right with bit 0

rotated to bit 7.

Operation

Affected flag(s)

[m].i ¬ [m].(i+1); [m].i:bit i of the data memory (i=0~6) [m].7 ¬ [m].0

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

44 August 18, 1999

HT49C50

RRA [m] Rotate right-place result in the accumulator

Description Data in the specified data memory is rotated one bit right with bit 0 rotated

into bit 7, leaving the rotated result in the accumulator. The contents of the data memory remain unchanged.

Operation

Affected flag(s)

RRC [m] Rotate data memory right through carry

Description The contents of the specified data memory and the carry flag are together ro

Operation

Affected flag(s)

ACC.(i) ¬ [m].(i+1); [m].i:bit i of the data memory (i=0~6) ACC.7 ¬ [m].0

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

tated one bit right. Bit 0 replaces the carry bit; the original carry flag is ro tated into the bit 7 position.

[m].i ¬ [m].(i+1); [m].i:bit i of the data memory (i=0~6) [m].7 ¬ C C ¬ [m].0

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾ Ö

RRCA [m] Rotate right through carry-place result in the accumulator

Description Data of the specified data memory and the carry flag are rotated one bit

right. Bit 0 replaces the carry bit and the original carry flag is rotated into the bit 7 position. The rotated result is stored in the accumulator. The contents of the data memory remain unchanged.

Operation

Affected flag(s)

ACC.i ¬ [m].(i+1); [m].i:bit i of the data memory (i=0~6) ACC.7 ¬ C C ¬ [m].0

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾ Ö

45 August 18, 1999

HT49C50

SBC A,[m] Subtract data memory and carry from the accumulator

Description The contents of thespecifieddatamemory and the complementofthecarry flag

aresubtractedfromtheaccumulator,leaving the resultin theaccumulator.

Operation

Affected flag(s)

SBCM A,[m] Subtract data memory and carry from the accumulator

Description The contents of the specified data memory and the complement of the carry

Operation

Affected flag(s)

SDZ [m] Skip if decrement data memory is zero

Description The contents of the specified data memory are decremented by one. If the re

Operation

Affected flag(s)

ACC ¬ ACC+[m

TC2 TC1 TO PD OV Z AC C

¾¾¾¾ÖÖÖÖ

flag are subtracted from the accumulator, leaving the result in the data memory.

[m] ¬ ACC+[m

TC2 TC1 TO PD OV Z AC C

¾¾¾¾ÖÖÖÖ

sult is zero, the next instruction is skipped. If the result is zero, the following instruction, fetched during the current instruction execution, is discarded and a dummy cycle is replaced to get the proper instruction (two cycles). Otherwise proceed with the next instruction (one cycle).

Skip if ([m]-1)=0, [m] ¬ ([m]-1)

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

]+C

SDZA [m] Decrement data memory and place result in ACC, skip if zero

Description The contents of the specified data memory are decremented by one. If the re

sult is zero, the next instruction is skipped. The result is stored in the accu mulator but the data memory remains unchanged. If the result is zero, the following instruction, fetched during the current instruction execution, is discarded and a dummy cycle is replaced to get the proper instruction (two cycles). Otherwise proceed with the next instruction (one cycle).

Operation

Affected flag(s)

Skip if ([m]-1)=0, ACC ¬ ([m]-1)

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

46 August 18, 1999

HT49C50

SET [m] Set data memory

Description Each bit of the specified data memory is set to one.

Operation

Affected flag(s)

SET [m].i Set bit of data memory

Description

Operation

Affected flag(s)

SIZ [m] Skip if increment data memory is zero

Description The contents of the specified data memory are incremented by one. If the re

Operation

Affected flag(s)

[m] ¬ FFH

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

Bit ²i² of the specified data memory is set to one. [m].i ¬ 1

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

sult is zero, the following instruction, fetched during the current instruction execution, is discarded and a dummy cycle is replaced to get the proper in struction (two cycles). Otherwise proceed with the next instruction (one cy cle).

Skip if ([m]+1)=0, [m] ¬ ([m]+1)

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

SIZA [m] Increment data memory and place result in ACC, skip if zero

Description The contents of the specified data memory are incremented by one. If the re-

sult is zero, the next instruction is skipped and the result is stored in the accumulator. The data memory remains unchanged. If the result is zero, the following instruction, fetched during the current instruction execution, is discarded and a dummy cycle is replaced to get the proper instruction (two cycles). Otherwise proceed with the next instruction (one cycle).

Operation

Affected flag(s)

Skip if ([m]+1)=0, ACC ¬ ([m]+1)

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

47 August 18, 1999

HT49C50

SNZ [m].i

Description

Operation

Affected flag(s)

SUB A,[m] Subtract data memory from the accumulator

Description The specified data memory is subtracted from the contents of the accumula

Operation

Affected flag(s)

SUBM A,[m] Subtract data memory from the accumulator

Description The specified data memory is subtracted from the contents of the accumula-

Operation

Affected flag(s)

Skip if bit ²i² of the data memory is not zero If bit ²i² of the specified data memory is not zero, the next instruction is

skipped. If bit ²i² of the data memory is not zero, the following instruction, fetched during the current instruction execution, is discarded and a dummy cycle is replaced to get the proper instruction (two cycles). Otherwise proceed with the next instruction (one cycle).

Skip if [m].i¹0

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

tor, leaving the result in the accumulator. ACC ¬ ACC+[m

TC2 TC1 TO PD OV Z AC C

¾¾¾¾ÖÖÖÖ

tor, leaving the result in the data memory. [m] ¬ ACC+[m

TC2 TC1 TO PD OV Z AC C

¾¾¾¾ÖÖÖÖ

]+1

SUB A,x Subtract immediate data from the accumulator

Description The immediate data specified by the code is subtracted from the contents of

the accumulator, leaving the result in the accumulator.

Operation

Affected flag(s)

ACC ¬ ACC+x

TC2 TC1 TO PD OV Z AC C

¾¾¾¾ÖÖÖÖ

48 August 18, 1999

HT49C50

SWAP [m] Swap nibbles within the data memory

Description The low-order and high-order nibbles of the specified data memory (one of

the data memories) are interchanged.

Operation

Affected flag(s)

SWAPA [m] Swap data memory-place result in the accumulator

Description The low-order and high-order nibbles of the specified data memory are inter

Operation

Affected flag(s)

SZ [m] Skip if data memory is zero

Description If the contents of the specified data memory are zero, the following instruc

Operation Skip if [m]=0

Affected flag(s)

[m].3~[m].0 « [m].7~[m].4

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

changed, writing the result to the accumulator. The contents of the data memory remain unchanged.

ACC.3~ACC.0 ¬ [m].7~[m].4 ACC.7~ACC.4 ¬ [m].3~[m].0

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

tion, fetched during the current instruction execution, is discarded and a dummy cycle is replaced to get the proper instruction (two cycles). Otherwise proceed with the next instruction (one cycle).

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

SZA [m] Move data memory to ACC, skip if zero

Description The contents of the specified data memory are copied to the accumulator. If

the contents is zero, the following instruction, fetched during the current in struction execution, is discarded and a dummy cycle is replaced to get the proper instruction (two cycles). Otherwise proceed with the next instruction (one cycle).

Operation

Affected flag(s)

Skip if [m]=0, ACC ¬ [m]

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

49 August 18, 1999

HT49C50

SZ [m].i

Description

Operation Skip if [m].i=0

Affected flag(s)

TABRDC [m] Move the ROM code (current page) to TBLH and data memory

Description The low byte of ROM code (current page) addressed by the table pointer

Operation

Affected flag(s)

TABRDL [m] Move the ROM code (last page) to TBLH and data memory

Description The low byte of ROM code (last page) addressed by the table pointer (TBLP)

Operation

Affected flag(s)

Skip if bit ²i² of the data memory is zero If bit ²i² of the specified data memory is zero, the following instruction,

fetched during the current instruction execution, is discarded and a dummy cycle is replaced to get the proper instruction (two cycles). Otherwise proceed with the next instruction (one cycle).

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

(TBLP) is moved to the specified data memory and the high byte transferred to TBLH directly.

[m] ¬ ROM code (low byte) TBLH ¬ ROM code (high byte)

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

is moved to the data memory and the high byte transferred to TBLH directly. [m] ¬ ROM code (low byte)

TBLH ¬ ROM code (high byte)

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾¾¾¾

XOR A,[m] Logical XOR accumulator with data memory

Description Data in the accumulator and the indicated data memory perform a bitwise

logical Exclusive_OR operation and the result is stored in the accumulator.

Operation

Affected flag(s)

ACC ¬ ACC ²XOR² [m]

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾Ö¾¾

50 August 18, 1999

HT49C50

XORM A,[m] Logical XOR data memory with the accumulator

Description Data in the indicated data memory and the accumulator perform a bitwise

logical Exclusive_OR operation. The result is stored in the data memory. The zero flag is affected.

Operation

Affected flag(s)

XOR A,x Logical XOR immediate data to the accumulator

Description Data in the the accumulator and the specified data perform a bitwise logical

Operation

Affected flag(s)

[m] ¬ ACC ²XOR² [m]

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾Ö¾¾

Exclusive_OR operation. The result is stored in the accumulator. The zero flag is affected.

ACC ¬ ACC ²XOR² x

TC2 TC1 TO PD OV Z AC C

¾¾¾¾¾Ö¾¾

51 August 18, 1999

HT49C50

Holtek Semiconductor Inc. (Headquarters)

No.3 Creation Rd. II, Science-based Industrial Park, Hsinchu, Taiwan, R.O.C. Tel: 886-3-563-1999 Fax: 886-3-563-1189

Holtek Semiconductor Inc. (Taipei Office)

5F, No.576, Sec.7 Chung Hsiao E. Rd., Taipei, Taiwan, R.O.C. Tel: 886-2-2782-9635 Fax: 886-2-2782-9636 Fax: 886-2-2782-7128 (International sales hotline)

Holtek Microelectronics Enterprises Ltd.

RM.711, Tower 2, Cheung Sha Wan Plaza, 833 Cheung Sha Wan Rd., Kowloon, Hong Kong Tel: 852-2-745-8288 Fax: 852-2-742-8657

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 pres ent a risk to human life due to malfunction or otherwise. 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.

52 August 18, 1999

Datasheet HT49C50 Datasheet (Holtek Semiconductor Inc)

Specifications and Main Features

Frequently Asked Questions

User Manual

Features

General Description

Block Diagram

Pin Assignment

Pad Assignment

Pin Description

Absolute Maximum Ratings

D.C. Characteristics

A.C. Characteristics

Functional Description

Application Circuits

Instruction Set Summary

Instruction Definition