
May 2002
Specifications subject to change without notice,contact your sales representatives for the most recent information.
13/32
Ver 1.0
PID 59264 05/02
SyncMOS Technologies Inc. SM59264
After N determined, SM59264 will reserve the ISP service program space downward from the top of the program address
$FFFF. The start address of the ISP service program located at $Fx00 while x is an even number, depending on the lock bit
N. Please see page 7 program memory diagram for this ISP service program space structure.
The lock bit N function is different from the flash protect function. The chip erase function can erase all of the flash memory
space including 64KB program flash & 64KB data flash, except for the locked ISP service program space. If the flash not
been protected, the content of flash program still can be read. If the flash been protected, the overall content of flash pro-
gram 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 SM59264 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 exe-
cute 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 ser-
vice program.
(2) Execute ‘JUMP’ instruction can load the start address of the ISP service program to PC.
(3) Enter’s ISP service program by hardware setting. User can force SM59264 enter ISP service program by setting P2.6,
P2.7 “l(fā)ow or P4.3 “l(fā)ow” during hardware reset period. In application system design, user should take care of the setting
of P2.6, P2.7 and P4.3 at reset period to prevent SM59264 from entering ISP service program.
Enters ISP service program by hardware setting:
or
P2.6
RST
P2.7
10ms
10ms
RST
P4.3
10ms
10ms