Cmsemicon CMS80F731 Series, Справочное руководство

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CMS80F731x Reference Manual
BOOT Control Register (BOOTCON)
F691H Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
BOOTCON D7 D6 D5 D4 D3 D2 D1 D0
R/W 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
Bit7~Bit0 D<7:0>:
BOOT zone control bit (this register can only be written when the chip is configured to
BOOT_1K/BOOT_2K/BOOT_4K);
0x55=
If you switch from the APROM area to the BOOT area, you need to write 0x55 to it, and then perform
a software reset or generate a watchdog reset;
0xAA=
If you switch from the BOOT area to the APOROM area, you need to write 0xAA to it, and then
perform a software reset or generate a watchdog reset;
Other
values=
Invalid.
For example, after the chip is powered on and booted from the BOOT area, use the software reset method to switch to the
APROM area, and the configuration is as follows:
1)
The BOOTCON register needs to write AAH
MOVDPTR,# BOOTCON
MOVE,#0AAH
MOVX@DPTR,A
2)
Perform a software reset
MOVTA,#0AAH
MOVTA,#055H
MOVWDCON,#080H
For example, use the software reset method to switch from the APROM area to the BOOT area, and configure it as follows:
1)
The BOOTCON register needs to write 55H
MOVDPTR
，
# BOOTCON
MOVA,#055H
MOVX@DPTR,A
2)
Perform a software reset
MOVTA,#0AAH
MOVTA,#055H
MOVWDCON,#080H
Note: When the BOOT function is valid, the APROM program needs to ensure that the PC does not overflow (overflow
means that the PC is out of the address range of the APROM), and if the PC overflows, the system may run
abnormally.