User manual

PCE-5125 User Manual 94
C.1 Supported GPIO Register
Below are the detailed descriptions of the GPIO addresses and programming sam-
ple.
C.2 GPIO registers
CRF0 (GP10-GP17 I/O selection register. Default 0xFF)
When set to a '1', respective GPIO port is programmed as an input port.
When set to a '0', respective GPIO port is programmed as an output port.
CRF1 (GP10-GP17 data register. Default 0x00)
If a port is programmed to be an output port, then its respective bit can be read/writ-
ten.
If a port is programmed to be an input port, then its respective bit can only be read.
CRF2 (GP10-GP17 inversion register. Default 0x00)
When set to a '1', the incoming/outgoing port value is inverted.
When set to a '0', the incoming/outgoing port value is the same as in data register.
Extended Function Index Registers (EFIRs)
The EFIRs are write-only registers with port address 2Eh or 4Eh on PC/AT systems.
Extended Function Data Registers (EFDRs)
The EFDRs are read/write registers with port address 2Fh or 4Fh on PC/AT systems.
C.3 GPIO example program-1
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Enter the extended function mode, interruptible double-write
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MOV DX,4EH
MOV AL,87H
OUT DX,AL
OUT DX,AL
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Configure logical device 7(GP10~GP17), configuration register CRF0,CRF1,CRF2
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MOV DX,4EH
MOV AL,07H ; Point to Logical Device Number Reg.
OUT DX,AL
MOV DX,4FH
MOV AL,07H ; Select logical device 7
OUT DX,AL ;
MOV DX,4EH
MOV AL,F0
OUT DX,AL