Datasheet

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4.21 GPIO Select Register

The GPIO select register is used to program the GPIOx terminal functions.

Bit 7 6 5 4 3 2 1 0

Name GPIO select

Type R R RU RU RW RW RW RW

Default 0 0 0 0 0 0 0 0

Type: Read/Update/Write

Offset: 44h

Default: 00h

Table 4−8. GPIO Select Register

BIT FIELD NAME TYPE DESCRIPTION

7−6 RSVD R Reserved. Bits 7 and 6 return 0s when read.

5 GPIO5Pin RU

GPIO5 pin. The value of this pin determines the function of GPIO5.

0 = Normal GPIO data (default)

1 = GP_RD. Read strobe (RD) for the GP bus. The PCI2040 will set this bit when bit 5 (GP_EN) in the

miscellaneous control register is set (see Section 4.26). Clearing bit 5 (GP_EN) will automatically

clear this bit.

4 GPIO4Pin RU

GPIO4 pin. The value of this pin determines the function of GPIO4.

0 = Normal GPIO data (default)

1 = GPWR. Write strobe (WR) for the GP bus. The PCI2040 will set this bit when bit 5 (GP_EN) in the

miscellaneous control register is set (see Section 4.26). Clearing bit 5 (GP_EN) will automatically

clear this bit.

3 GPIO3Pin RW

GPIO3 pin. The value of this pin determines the function of GPIO3. When programmed as an interrupt

event input, the event is selected in the GPIO interrupt event type register (see Section 4.25). When

programmed as a normal GPIO, the IntGPIO3 interrupt event will never occur.

0 = Normal GPIO data (default)

1 = GPIO3 is an interrupt event input

2 GPIO2Pin RW

GPIO2 pin. The value of this pin determines the function of GPIO2. When programmed as an interrupt

event input, the event is selected in the GPIO interrupt event type register (see Section 4.25). When

programmed as a normal GPIO, the IntGPIO2 interrupt event will never occur.

0 = Normal GPIO data (default)

1 = GPIO2 is an interrupt event input

1 GPIO1Pin R

GPIO1 pin. The value of this pin determines the function of GPIO1.

0 = Normal GPIO data (default)

1 = Reserved.

0 GPIO0Pin R

GPIO0 pin. The value of this pin determines the function of GPIO0.

0 = Normal GPIO data (default)

1 = Reserved.