Omega OME-PIO-D144 manual 9 I/O Selection Control Register, CN2PC CN2PB CN2PA CN1PC CN1PB CN1PA

3.3.9I/O Selection Control Register

(Write): wBase+0xc8

Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
0	0	CN2_PC	CN2_PB	CN2_PA	CN1_PC	CN1_PB	CN1_PA
(Write): wBase+0xcc
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
0	0	CN4_PC	CN4_PB	CN4_PA	CN3_PC	CN3_PB	CN3_PA
(Write): wBase+0xd0
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
0	0	CN6_PC	CN6_PB	CN6_PA	CN5_PC	CN5_PB	CN5_PA

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

For example:

CN1_PA=1Æ Port is used as a D/I port.

CN1_PA=0Æ Port is used as a D/O port.

There are eighteen 8-bit I/O ports in the OME-PIO-D144. Every I/O port can be programmed as D/I or D/O port. When the PC is first powered up, all eighteen ports are used as D/I port. The I/O port location is given as follows:

Connector of OME-PIO-	PA0 to PA7	PB0 to PB7		PC0 to PC7
D144
CN1	CN1_PA	CN1_PB		CN1_PC
CN2	CN2_PA	CN2_PB		CN2_PC
CN3	CN3_PA	CN3_PB		CN3_PC
CN4	CN4_PA	CN4_PB		CN4_PC
CN5	CN5_PA	CN5_PB		CN5_PC
CN6	CN6_PA	CN6_PB		CN6_PC
outp(wBase+0xc8,0);	/* CN1_PA/PB/PC to CN2_PA/PB/PC are all D/O port */
outp(wBase+0xcc,0x3f);	/* CN3_PA/PB/PC to CN4_PA/PB/PC are all D/I port */
outp(wBase+0xd0,0x38);	/* CN5_PA/PB/PC are all D/O port */
	/* CN6_PA/PB/PC are all D/I port		*/

Refer to Sec. 2.2 for I/O Port Location.

OME-PIO-D144 User’s Manual (Ver.2.1, Sep/2001) ---- 32