Rainbow Electronics W90N745CDG User Manual
Page 318
W90N745CD/W90N745CDG
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6.13 General-Purpose Input/Output
The General-Purpose Input/Output (GPIO) module possesses 31 pins and serves multiple function
purposes. Each port can be configured by software to meet various system configurations and design
requirements. Software must configure each pin before starting the main program. If a pin is not used for
multiplexed functions, the pin can be configured as I/O port
Two extended interrupts nIRQ2 (GPIO0 pin) and nIRQ3 (nWAIT pin) are used the same interrupt request
(channel #31) of AIC. It can be programmed as low/high sensitive or positive/negative edge triggered.
When interrupt #31 assert in AIC, software can poll XISTATUS status register to identify which interrupt
occur.
These 31 IO pins are divided into 7 groups according to its peripheral interface definition.
y
Port0: 5-pin input/output port
y
Port1: 2-pin input/output port
y
Port2: 10-pin input/output port
y
Port3: Reserved
y
Port4: 1-pin input/output port
y
Port5: 13-pin input/output port need updated
y
Port6:
Reserved
Table 6.13.1 GPIO multiplexed functions table
PORT0
Configurable Pin Functions
0
GPIO0
AC97_nRESET
(I²S_MCLK)
nIRQ2 USBPWREN
1
GPIO1
AC97_DATAI (I²S_DATAI)
PWM0
DTR3
2
GPIO2
AC97_DATAO
(I²S_DATAO)
PWM1 DSR3
3
GPIO3
AC97_SYNC
(I²S_LRCLK)
PWM2 TXD3
4
GPIO4
AC97_BITCLK
(I²S_BITCLK)
PWM3 RXD3
PORT1
Configuration Pin Functions
0 GPIO18 -
nXDACK -
1 GPIO19 -
nXDREQ -
PORT2
Configuration Pin Functions
0 GPIO20 PHY_RXERR
KPCOL0 -
1 GPIO21 PHY_CRSDV
KPCOL1 -
2 GPIO22 PHY_RXD[0]
KPCOL2 -
3 GPIO23 PHY_RXD[1]
KPCOL3 -