SMC Networks 1232 Series user manual Out Dx, Al, Inc, Al, Dx, Mov Bl, Al, Mov Al, Bl

MOV	AL, 55h	; SPIO Configuration Mode Enable Key
OUT	DX, AL	; Enter in configuration mode

; Select Logical Device 8 (watch dog) ...

MOV	DX, 3F0h	; SPIO Index Port
MOV	AL, 07h	; Logical Device selector is the register 7
OUT	DX, AL	; Point to Logical Device selector
INC	DX	; SPIO Data Port
MOV	AL, 08h	; Logical Device number 8
OUT	DX, AL	; Select the Logical Device 8

; Select the time base (seconds or minutes) ...

	MOV	DX, 3F0h	; SPIO Index Port
	MOV	AL, F1h	; Watchdog timer units register (WDT_UNITS)
	OUT	DX, AL	; Point to register WDT_UNITS
	INC	DX	; SPIO Data Port
	IN	AL, DX	; Read WDT_UNITS
	OR	AL, 01h	; Mask reserved bits and set time in seconds
;	AND	AL, FEh	; Mask reserved bits and set time in minutes
	MOV	BL, AL	; Save new WDT_UNITS value
	MOV	DX, 3F0h	; SPIO Index Port
	MOV	AL, F1h	; Watchdog timer units register (WDT_UNITS)
	OUT	DX, AL	; Point to register WDT_UNITS
	INC	DX	; SPIO Data Port
	MOV	AL, BL	; WDT_UNITS value
	OUT	DX, AL	; Write the new WDT_UNITS value

; Select the watchdog timer timeout value ...

MOV	DX, 3F0h	; SPIO Index Port
MOV	AL, F2h	; Watchdog timeout value (WDT_VAL)
OUT	DX, AL	; Point to register WDT_ VAL
INC	DX	; SPIO Data Port
MOV	AX, 37	; New WDT_ VAL value (from 0 to 255 - seconds in this
case)
OUT	DX, AL	; Write the new WDT_ VAL value

; SPIO: exit from configuration mode ...

MOV	DX, 3F0h	; SPIO Index Port
MOV	AL, 0AAh	; SPIO Configuration Mode Disable Key
OUT	DX, AL	; Exit from configuration mode

•Note: for further information about the watchdog programming, refer to “FDC 37B78x Advance Information” manual from SMSC.

68