;*************************************************************************; An 8051 Based Web Server; csio.a51: driver code for CS8900A chip located at 7000h; By Mason Kidd 10/25/01;*************************************************************************$NOMOD51$INCLUDE(reg515.inc)name		csioapublic		_write_byte, _read_byte, _write_word, _read_wordL, _read_wordH sc_csio	SEGMENT	CODE		RSEG	sc_csio 		               USING 0               csio_port	EQU	70h               ; write_byte(io_port = R7, data = R5)_write_byte:	push	ACC	mov	A, R7	add	A, #csio_port	mov	DPH, A	mov	A, R5	movx	@DPTR, A	pop	ACC	ret	; read_byte(io_port = R7), value returned in R7_read_byte:	push	ACC	mov	A, R7	add	A, #csio_port	mov	DPH, A	movx	A, @DPTR	mov	R7, A	pop	ACC	ret	; write_word(io_port = R7, data = R4R5); send the low order byte first(R5)_write_word:	push	ACC	mov	A, R7	add	A, #csio_port	mov	DPH, A	mov	A, R5	movx	@DPTR, A	mov	A, R7	add	A, #csio_port	inc	A	mov	DPH, A	mov	A, R4	movx	@DPTR, A	pop	ACC	ret	; read_wordL(io_port = R7) return in R6R7; read the low order byte first(R7)_read_wordL:	push	ACC	mov	A, R7	mov	R1, A	add	A, #csio_port	mov	DPH, A	movx	A, @DPTR	mov	R7, A	mov	A, R1	add	A, #csio_port	inc	A	mov	DPH, A	movx	A, @DPTR	mov	R6, A	pop	ACC	ret	; read_wordH(io_port = R7) return in R6R7; read the high order byte first(R6)_read_wordH:	push	ACC	mov	A, R7	mov	R1, A	add	A, #csio_port	inc	A	mov	DPH, A	movx	A, @DPTR	mov	R6, A	mov	A, R1	add	A, #csio_port	mov	DPH, A	movx	A, @DPTR	mov	R7, A	pop	ACC	ret	       end