HT49CV3 datasheet(7/44 Pages) HOLTEK

7 / 44 page

HT49RV3/HT49CV3

Rev. 1.30

March 20, 2007

The lower byte of the program counter (PCL) is avail-

able for program control and is a readable and writeable

short jump. The destination will be within 256 locations.

When a control transfer takes place, an additional

dummy cycle is required.

Program Memory

- EPROM

The program memory (EPROM) is used to store the pro-

gram instructions which are to be executed. It also con-

tains data, table, and interrupt entries, and is organized

into 2048

´16 bits format. The program counter is com-

posed of 11 bits, so it can directly access the whole pro-

gram memory without changing banks.

Certain locations in the ROM are reserved for special

usage:

· Location 000H

This area is reserved for use by the chip reset for pro-

gram initialization. After a chip reset is initiated, the

program will jump to this location and begin execution.

· Location 004H

This area is reserved for the external interrupt service

program. If the INT0 input pin is activated, and the in-

terrupt is enabled, and the stack is not full, the pro-

gram will jump to this location and begin execution.

· Location 008H

This area is reserved for the external interrupt service

program. If the INT1 input pin is activated, and the in-

terrupt is enabled, and the stack is not full, the pro-

gram will jump to this location and begin execution.

· Location 00CH

This area is reserved for the Timer/Event Counter 0 in-

terrupt service program. If a timer interrupt results

from a Timer/Event Counter 0 overflow, and if the in-

terrupt is enabled and the stack is not full, the program

will jump to this location and begin execution.

· Location 010H

This area is reserved for the Timer/Event Counter 1 in-

terrupt service program. If a timer interrupt results

from a Timer/Event Counter 1 overflow, and if the in-

terrupt is enabled and the stack is not full, the program

will jump to this location and begin execution.

· Location 014H

This area is reserved for the Serial Interface interrupt

service program. If 8 bits of data have been received or

transmitted successfully from the serial interface, and

the interrupt is enabled, and the stack is not full, the

program will jump to this location and begin execution.

· Location 018H

This area is reserved for the multi-function interrupt. If

a real time clock interrupt occurs, or if a rising edge is

detected from the RMT input pin, or if a falling edge is

detected from the RMT input pin, or if the RMT over-

flow and the related interrupts are enabled, and the

stack is not full, the program will jump to this location

and begin execution.

· Table location

Any location within the program memory can be used

as a look-up table where programmers can store fixed

data. 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

byte in the table is well-defined, the other bits of the ta-

ble word are all transferred to the lower portion of

TBLH. The TBLH is a read only register and the table

pointer (TBLP) is a read/write register (07H), which in-

dicates the table location. Before accessing the table,

the location must be placed in the TBLP. All table re-

lated instructions require two cycles to complete the

operation. These areas may function as normal pro-

gram memory depending upon user

¢s requirements.

P r o g r a m

R O M

0 0 0 H

0 0 4 H

0 0 8 H

0 1 4 H

0 1 8 H

0 0 C H

0 1 0 H

1 6 b i t s

N o t e : n r a n g e s f r o m 0 t o 7

7 F F H

n 0 0 H

n F F H

D e v i c e I n i t i a l i z a t i o n P r o g r a m

E x t e r n a l I n t e r r u p t 0 S u b r o u t i n e

T i m e r / E v e n t C o u n t e r 0 I n t e r r u p t S u b r o u t i n e

E x t e r n a l I n t e r r u p t 1 S u b r o u t i n e

M u l t i - f u n c t i o n I n t e r r u p t

L o o k - u p T a b l e ( 2 5 6 W o r d s )

T i m e r / E v e n t C o u n t e r 1 I n t e r r u p t S u b r o u t i n e

S e r i a l I n t e r f a c e I n t e r r u p t

Program Memory

Instruction(s)

Table Location

*10

TABRDC [m]

P10

TABRDL [m]

Table Location

Note:

*10~*0: Table location bits

P10~P8: Current program counter bits

@7~@0: Table pointer bits

HT49CV3 Datasheet(PDF) 7 Page - Holtek Semiconductor Inc

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