W78E58B Winbond, W78E58B Datasheet - Page 13

• Manufacturer Part Number: W78E58B
• Description: 8 BIT MICROCONTROLLER
• Manufacturer: Winbond

In-System Programming Control Register (CHPCON)
CHPCON (BFH)
F04KBOOT Mode (Boot From LDROM)
By default, the W78E58B boots from APROM program after a power on reset. On some occasions,
user can force the W78E58B to boot from the LDROM program via following
situation that you need to enter F04KBOOT mode when the APROM program can not run properly and
device can not jump back to LDROM to execute in-system programming function. Then you can use
this F04KBOOT mode to force the W78E58B jumps to LDROM and executes in-system programming
procedure. When you design your system, you may reserve the pins P2.6, P2.7 to switches or
jumpers. For example in a CD-ROM system, you can connect the P2.6 and P2.7 to PLAY and EJECT
buttons on the panel. When the APROM program fails to execute the normal application program.
User can press both two buttons at the same time and then turn on the power of the personal
computer to force the W78E58B to enter the F04KBOOT mode. After power on of personal computer,
you can release both buttons and finish the in-system programming procedure to update the APROM
code. In application system design, user must take care of the P2, P3, ALE, EA and PSEN pin value
at reset to prevent from accidentally activating the programming mode or F04KBOOT mode.
BIT
7
6
5
4
3
2
1
0
ENAUXRAM
SWRESET
(F04KMODE)
FPROGEN
FBOOTSL
NAME
0
0
-
-
1: enable. The microcontroller enter the in-system programming mode after
0: disable. The on-chip flash memory is read-only. In-system programmability
When this bit is set to 1, and both FBOOTSL and FPROGEN are set to 1. It will
enforce microcontroller reset to initial condition just like power on reset. This
action will re-boot the microcontroller and start to normal operation. To read this
bit in logic-1 can determine that the F04KBOOT mode is running.
Reserve.
Reserve.
1: Enable on-chip AUX-RAM.
0: Disable the on-chip AUX-RAM
Must set to 0.
Must set to 0.
The Program Location Select.
0: The Loader Program locates at the 32 KB APROM. 4KB LDROM is
1: The Loader Program locates at the 4 KB memory bank. 32KB APROM is
ROM Programming Enable.
destination for re-programming.
destination for re-programming.
entering the idle mode and wake-up from interrupt. During in-system
programming mode, the operation of erase, program and read are achieve
when device enters idle mode.
is disabled.
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FUNCTION
Publication Release Date: March 18, 2002
settings.
W78E58B
The possible
Revision A3