Ttl I/O(Gpio) Programming - FabiaTech FX5653 User Manual

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
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
Mov dx,2fh
Mov al,07h
Mov dx,al
Mov dx,2eh
Mov al,f0h
Out dx,al
Mov dx,2fh
Mov al,03h
Out dx,al
Mov dx,2eh
Mov al,f1h
Out dx,al
Mov dx,2fh
In al,dx
And al,03h
Mov ah,0ch
Or al,ah
Out dx,al
; Enter to extended function mode
; point to Logical Device Number Reg.
; Select Logical devive 7
;Select CRF0
;Set GP0-1 is input and GP2-3 is output
;update CRF0 with value 0Fh
;Select CRF1
;read GP0-1 value
;Set GP2-3 value is "xxxx11xxb"
; update CRF1 with value
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