W79E201 Datasheet, PDF (65/87 Pages) Winbond – 8-BIT MICROCONTROLLER

W79E201
18. IN-SYSTEM PROGRAMMING
18.1 The Loader Program Locates at LD Flash EPROM Memory
CPU is Free Run at AP Flash EPROM memory. CHPCON register had been set #03H value before
CPU has entered idle state. CPU will switch to LD Flash EPROM memory and execute a reset action.
H/W reboot mode will switch to LD Flash EPROM memory, too. Set SFRCN register where it locates
at user's loader program to update AP Flash EPROM memory. Set a SWRESET (CHPCON=#83H) to
switch back AP Flash EPROM after CPU has updated AP Flash EPROM program. CPU will restart to
run program from reset state.
18.2 The Loader Program Locates at AP Flash EPROM Memory
CPU is Free Run at AP Flash EPROM memory. CHPCON register had been set #01H value before
CPU has entered idle state. Set SFRCN register to update LD Flash EPROM program. CPU will
continue to run user's AP Flash EPROM program after CPU has updated program. Please refer
demonstrative code to understand other detail description.
19. H/W WRITER MODE
This mode is for the writer to write / read Flash EPROM operation. A general user may not enter this
mode.
The Timing For Entering Flash EPROM
Mode on the Programmer
EA
PSEN
ALE
P2.7
P2.6
P3.7
P3.6
RST
300ms
10ms
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
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Publication Release Date: December 16, 2004
Revision A2