Rainbow Electronics W90N740 - Manual (Page 192)

W90N740
- 188 -
7.12 General-Purpose Input/Output Controller (GPIO)
The General-Purpose Input/Output (GPIO) module possesses 21 pins and serves multiple purposes.
The Features of the GPIO Controller:
• Programmable as an input or output pin
• Includes de-bouncer circuits on GPIO20, GPIO19, GPIO18, and GPIO17 which can be turned
off if not requir
For example, GPIO20 ~ GPIO17 can be programmed as external interrupt input pins, GPIO16 ~ GPIO15
for external DMA function, GPIO14 ~ GPIO13 for TIMER tone output, GPIO12 as the watchdog timeout
flag, GPIO11 ~ GPIO10 used for UART console monitor, GPIO9 ~ GPIO4 for modem. The table as
shown below is a summary.
Table 7.12.1 GPIO Pin Assignment of Multi-Function
General-purpose
I/O
Multi-function 1
Multi-function 2
(USB IO Port) GPIO
Name Type Name Type Name Type
GPIO20 GP20 IO nIRQ3 I - -
GPIO19 GP19 IO nIRQ2 I - -
GPIO18 GP18 IO nIRQ1 I OVRCUR I
GPIO17 GP17 IO nIRQ0 I - -
GPIO16 GP16 IO NXDREQ3 I - -
GPIO15 GP15 IO nXDACK O - -
GPIO14 GP14 IO TIMER1 O SPEED O
GPIO13 GP13 IO TIMER0 O STDBY O
GPIO12 GP12 IO nWDOG O PWRENX O
GPIO11 GP11 IO RxD I - -
GPIO10 GP10 IO TxD O - -
GPIO9 GP9 IOU nDSR IU nTOE O
GPIO8 GP8 IOU nDTR O FSE0 O
GPIO7 GP7 IOU nCD IU VO O
GPIO6 GP6 IOU nCTS IU VM IU
GPIO5 GP5 IOU nRTS O VP IU
GPIO4 GP4 IOU nRI IU RCV IU
GPIO3 GP3 IOU NXDREQ2 IU - -
GPIO2 GP2 IOU NXDREQ1 IU - -
GPIO1 GP1 IOU NWTC O - -
GPIO0 GP0 IOU NRTC O - -
Note: U means internal weak pull-up.