FabiaTech FX5653, Руководство пользователя, Страница: 68 / 85

FabiaTech Corporation
TTL I/O(GPIO) programming
The following is an Assembly program, which demonstrates how to set the GPIO
type and how to read and write values.
;------------------------------------------------------------------------------------------
; Enter the extended function mode, interruptible double-write
;------------------------------------------------------------------------------------------
Mov
dx, 2eh ; Enter to extended function mode
Mov al, 87h
Out dx,al
Out dx,al
;------------------------------------------------------------------------------------------------------
; Configurate logical device7 , configuration register CRF0,CRF1,CRF2
; CRF0 (GP0-GP7 I/O selection register.)
; When set to a “1”, respective GPIO port is programmed as input port.
; When set to a “0”, respective GPIO port is programmed as an output port.
; CRF1 (GP0-GP7 data register.)
; if a port is programmed to be an output port, then its respective bit can be
read/written.
; If a port is programmed to be an input port, then its respective bit can only
be read.
; CRF2 (GP0-7 inversion register.)
; When set to a “1”, the incoming/outgoing port value is inverted.
; When set to a “0”, the incoming/outgoing port value is same as in data
register.
;------------------------------------------------------------------------------------------------------
Mov dx,2eh
Mov al,07h
Out dx,al ; point to Logical Device Number Reg.
Mov dx,2fh
Mov al,07h
Mov dx,al ; Select Logical devive 7
Mov
dx,2eh
Mov al,f0h
Out dx,al ;Select CRF0
Mov dx,2fh
Mov al,03h ;Set GP0-1 is input and GP2-3 is output
Out dx,al ;update CRF0 with value 0Fh
Mov dx,2eh
Mov al,f1h
Out dx,al
;Select CRF1
Mov dx,2fh
In al,dx
And al,03h ;read GP0-1 value
Mov ah,0ch ;Set GP2-3 value is “xxxx11xxb”
Or al,ah
Out dx,al ; update CRF1 with value
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