Omega OME-PIO-D144 I/O Port Location, Enable I/O Operation, Refer to DEMO1.C for demo program

2.2I/O Port Location

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 ports. The I/O port location is given as following:

Connector of OME-PIO-D144	PA0 to PA7	PB0 to PB7	PC0 to PC7
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

Refer to Sec. 2.1 for board layout & I/O port location.

Note: PC0, PC1, PC2, PC3 of CN1 can be used as interrupt signal source. Refer to Sec. 2.5 for more information.

2.3Enable I/O Operation

When the PC is first powered up, all operation of D/I/O port are disable. The enable/disable of D/I/O is controlled by the RESET\ signal. Refer to Sec. 3.3.1 for more information about RESET\ signal. The power-on states are given as following:

•All D/I/O operations are disable

•All eighteen D/I/O ports are configured as D/I port

•All D/O latch register are undefined.(refer to Sec. 2.4)

The user has to perform some initialization before using these D/I/Os. The recommended steps are given as following:

Step 1: Make sure which ports are D/O ports.

Step 2: Enable all D/I/O operation.(refer to Sec. 3.3.1).

Step 3: Select the active port (refer to Sec. 3.3.8).

Step 4: Send initial-value to the D/O latch register of this active port. (Refer to Sec. 2.4 & Sec. 3.3.7)

Step 5: Repeat Step3 & Step4 for all D/O ports

Step 6: Configure all eighteen D/I/O ports to their expected D/I or D/O state. (Refer to Sec. 3.3.9)

Refer to DEMO1.C for demo program.

OME-PIO-D144 User’s Manual (Ver.2.1, Sep/2001) ---- 6