sm59264 SyncMOS Technologies,Inc, sm59264 Datasheet - Page 18

• Manufacturer Part Number: sm59264
• Description: 8-bits Micro-controller With 128kb Flash & 1kb Ram & Twsi & Spwm Embedded
• Manufacturer: SyncMOS Technologies,Inc

To perform the chip erase ISP function, SM59264 will erase all the flash program memory and data flash memory
except the ISP service program space if lock bit N been configured. Also, SM59264 will un-protect the flash memory
automatically. To perform chip protect ISP function, all the flash memory will be read #00H.
e.g. ISP service program to do the byte program -to program #22H to the address $1005H
4. Watch Dog Timer
The Watch Dog Timer (WDT) is a 16-bit free-running counter that generate reset signal if the counter overflows. The
WDT is useful for systems which are susceptible to noise, power glitches, or electronics discharge which causing
software dead loop or runaway. The WDT function can help user software recover from abnormal software condition.
The WDT is different from Timer0, Timer1 and Timer2 of general 8052. To prevent a WDT reset can be done by
software periodically clearing the WDT counter. User should check WDR bit of SCONF register whenever un-predicted
reset happened
The purpose of the secure procedure is to prevent the WDTC value from being changed when system runaway.
There is a 250KHz RC oscillator embedded in chip. Set WDTE = “1” will enable the RC oscillator and the frequency is
independent to the system frequency.
To enable the WDT is done by setting 1 to the bit 7 (WDTE) of WDTC. After WDTE set to 1, the 16-bit counter starts to
count with the RC oscillator. It will generate a reset signal when overflows. The WDTE bit will be cleared to 0
automatically when SM59264 been reset, either hardware reset or WDT reset.
To reset the WDT is done by setting 1 to the CLEAR bit of WDTC before the counter overflow. This will clear the
content of the 16-bit counter and let the counter re-start to count from the beginning.
4.1 Watch Dog Timer Registers:
Watch Dog Timer Registers - WDT Control Register (WDTC, $9F)
Specifications subject to change without notice contact your sales representatives for the most recent information.
ISSFD-M012 Ver B SM59264
e.g. flash address: $XYMN
page erase function will erase from $XY00 to $X(Y+1)FF (Y: even number), or
page erase function will erase from $X(Y-1)00 to $XYFF (Y: odd number)
MOV ISPFD, #55H
MOV ISPFD, #0AAH
MOV ISPFD, #55H
MOV 0BFh, #04H
MOV 0F4h, #10H
MOV 0F5h, #05H
MOV 0F6h, #22H
MOV 0F7h, #80H
SyncMOS Technologies International, Inc.
; set flash address-high, 10H
; set flash address-low, 05H
; set flash data to be programmed, data = 22H
; start to program #22H to the flash address $1005H
; enable SM59264 ISP function
; after byte program finished, START bit of FCR will be reset to 0 automatically
; program counter then point to the next instruction
with 128KB flash & 1KB RAM & TWSI & SPWM embedded
18
8-Bits Micro-controller
SM59264
05/2009