Microchip 16F690 I/O Port A

Programming | PIC's | 16F690 | I/O Port A

Port A is a 6 bit bit-directional port. Register TRISA sets the data direction for each bit.

Port A Register

7	6	5	4	3	2	1	0
U-0	U-0	R/W-x	R/W-x	R-x	R/W-x	R/W-x	R/W-x
		RA5	RA4	RA3	RA2	RA1	RA0

Bit	Kind	Name	Description
bit 7	U-0		Unimplemented bit
bit 6	U-0		Unimplemented bit
bit 5	R/W-X	RA5	General Purpose I/O bit 1 = pin is > Vih. 0 = pin is < Vil.
bit 4	R/W-X	RA4
bit 3	R-X	RA3
bit 2	R/W-X	RA2
bit 1	R/W-X	RA1
bit 0	R/W-X	RA0

TRISA Register

7	6	5	4	3	2	1	0
U-0	U-0	R/W-1	R/W-1	R-1	R/W-1	R/W-1	R/W-1
		TRISA5	TRISA4	TRISA3	TRISA2	TRISA1	TRISA0

Bit	Kind	Name	Description
bit 7	U-0		Unimplemented bit
bit 6	U-0		Unimplemented bit
bit 5	R/W-1	TRISA5	1 = pin is configured as an input. 0 = pin is configured as an output.
bit 4	R/W-1	TRISA4
bit 3	R-1	TRISA3
bit 2	R/W-1	TRISA2
bit 1	R/W-1	TRISA1
bit 0	R/W-1	TRISA0

Sample Initialization Code for Port C

        BCF     STATUS,RP0      ;Bank 0
        BCF     STATUS,RP1      ;
        CLRF    PORTA           ;Init PORTA
        BSF     STATUS,RP1      ;Bank 2
        CLRF    ANSEL           ;digital I/O
        BSF     STATUS,RP0      ;Bank 1
        BCF     STATUS,RP1      ;
        MOVLW   b'00001100'     ;Set RA3 and RA2 as inputs
        MOVWF   TRISA           ;and RA5, RA4, RA1, and RA0 as outputs
        BCF     STATUS,RP0      ;Bank 0