Omega OME-PIO-D144 manual Read/Write 8-bit data Register, Active I/O Port Control Register

3.3.7Read/Write 8-bit data Register

(Read/Write): wBase+0xc0

Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
D7	D6	D5	D4	D3	D2	D1	D0

Note. Refer to Sec. 3.1 for more information about wBase.

There are eighteen 8-bit I/O port in the OME-PIO-D144. Every I/O port can be programmed as D/I or D/O port. Refer to Sec. 3.3.9 for D/I or D/O selection. When the PC is first power-on, all eighteen ports are used as D/I port.

outp(wBase+0xc0,Val);	/* write to D/O port */
Val=inp(wBase+0xc0);	/* read from D/I port */

3.3.8Active I/O Port Control Register

(Read/Write): wBase+0xc4

Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
D7	D6	D5	D4	D3	D2	D1	D0

Note. Refer to Sec. 3.1 for more information about wBase.

There are eighteen 8-bit I/O port in the OME-PIO-D144. Only one I/O port can be active at the same time.

outp(wBase+0xc4,0);	/*	I/O port_0 is active now	*/
outp(wBase+0xc4,1);	/*	I/O port_1 is active now	*/
outp(wBase+0xc4,17);	/*	I/O port_17 is active now */

Refer to Sec. 2.2 for I/O port location.

OME-PIO-D144 User’s Manual (Ver.2.1, Sep/2001) ----- 31