HT46R652 datasheet(9/47 Pages) HOLTEK

9 / 47 page

HT46R652

Rev. 1.00

December 19, 2006

The lower byte of the PC, known as PCL is a readable

and writeable register. Moving data into the PCL per-

forms a short jump. The destination is within 256 loca-

tions.

When a control transfer takes place, an additional

dummy cycle is required.

Program Memory

The program memory is used to store the program in-

structions which are to be executed. It also contains

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

8192

´16 bits which are addressed by the program

counter and table pointer.

Certain locations in the ROM are reserved for special

usage:

· Location 000H

Location 000H is reserved for program initialization.

After a device reset, the program always begins exe-

cution at this location.

· Location 004H

Location 004H is reserved for the external interrupt

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 interrupt

service program also. If the INT1 input pin is activated,

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

the program begins execution at location 008H.

· Location 00CH

Location 00CH is reserved for the Timer/Event Coun-

ter 0 interrupt service program. If a timer interrupt re-

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

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

gram begins execution at location 00CH.

· Location 010H

Location 010H is reserved for the Timer/Event Coun-

ter 1 interrupt service program. If a timer interrupt re-

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

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

gram begins execution at location 010H.

· Location 014H

Location 014H is reserved for the Time Base interrupt

service program. If a Time Base interrupt 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 inter-

rupt service program. If a real time clock interrupt oc-

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

full, the program begins execution at location 018H.

· Table location

Any location in the Program Memory 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 which is the Table

Higher-order byte register. Only the destination of the

lower-order byte in the table is well-defined; the other

bits of the table word are all transferred to the lower

portion of TBLH. The TBLH register is read only, and

the table pointer, TBLP, is a read/write register, indi-

cating the table location. Before accessing the table,

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

lated instructions require 2 cycles to complete the op-

eration. These areas may function as a normal

Program Memory depending upon the user

¢s require-

ments.

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

1 6 b i t s

P r o g r a m

M e m o r y

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

N o t e : n r a n g e s f r o m 0 t o 1 F

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

T i m e B a s e I n t e r r u p t

R T C 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

0 0 0 H

0 0 4 H

0 0 8 H

0 1 4 H

1 F F F H

0 1 8 H

0 0 C H

n 0 0 H

n F F H

0 1 0 H

Program Memory

Instruction(s)

Table Location

*12

*11

*10

TABRDC [m]

P12

P11

P10

TABRDL [m]

Table Location

Note:

*12~*0: Table location bits

P12~P8: Current program counter bits

@7~@0: Table pointer bits

HT46R652 データシート(PDF) 9 Page - Holtek Semiconductor Inc

HT46R652 データシート(HTML) 9 Page - Holtek Semiconductor Inc

Html Pages

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 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47

データシートダウンロード