SyncMOS Technologies International, Inc.

SM5964

8-Bits Micro-controller

64KB ISP flash & 1KB RAM embedded

Specifications subject to change without notice contact your sales representatives for the most recent information.

Ver 2.2 SM5964 08/2006

10

The lock bit N function is different from the flash protect function. The flash erase function can erase all of the flash

memory except for the locked ISP service program space. If the flash not been protected, the content of ISP service

program still can be read. If the flash been protected, the overall content of flash program memory space including ISP

service program space can not be read.

3.3 Program the ISP Service Program

After Lock Bit N is set and ISP service program been programmed, the ISP service program memory will be protected

(locked) automatically. The lock bit N has its own program/erase timing. It is different from the flash memory

program/erase timing so the locked ISP service program can not be erased by flash erase function. If user need to

erase the locked ISP service program, he can do it by writer only. User can not change ISP service program when

SM5964 was in system.

3.4 Initiate ISP Service Program

To initiate the ISP service program is to load the program counter (PC) with start address of ISP service program

and execute it. There are three ways to do so:

(1) Blank reset. Hardware reset with first flash address blank ($0000=#FFH) will load the PC with start address of ISP

service program.

(2) Execute ‘JUMP’ instruction can load the start address of the ISP service program to PC.

User can initiate general 8052 INT function to initiate the ISP service program. After ISP service program executed,

user need to reset the SM5964, either by hardware reset or by WDT, or jump to the address $0000 to re-start the

firmware program.

ISP Registers - ISPFAH, ISPFAL, ISPFD and ISPC

ISP Flash Address-High Register(ISPFAH,$F4)

bit-7

bit-0

FA15

FA14

FA13

FA12

FA11

FA10

FA9

FA8

Read / Write:

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

Reset value:

0

0

0

0

0

0

0

0

FA15 ~ FA8: flash address-high for ISP function

ISP Flash Address-Low Register(ISPFAL,$F5)

bit-7

bit-0

FA7

FA6

FA5

FA4

FA3

FA2

FA1

FA0

Read / Write:

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

Reset value:

0

0

0

0

0

0

0

0

FA7 ~ FA0: flash address-low for ISP function

The ISPFAH & ISPFAL provide the 16-bit flash memory address for ISP function. The flash memory address should

not include the ISP service program space address. If the flash memory address indicated by ISPFAH & ISPFAL

registers overlay with the ISP service program space address, the flash program/page erase of ISP function executed

thereafter will have no effect.