5.15 General Purpose IO

Pin

 

Name

 

Default

 

Alternate function

 

 

 

 

 

 

 

21

 

GPIO1

 

GPIO1

 

 

22

 

GPIO2

 

GPIO2

 

 

23

 

GPIO3

 

GPIO3

 

 

24

 

GPIO4

 

GPIO4

 

 

13

 

GPIO5

 

ADIN4

 

ADC Input 4

33

 

GPIO6

 

LED

 

LED control signal

32

 

GPIO7

 

DSR1

 

Data Set Ready (UART1)

36

 

GPIO8

 

RI

 

Ring Indicator

39

 

GPIO9

 

RTS1

 

Ready To Send (UART1)

37

 

GPIO10

 

DTR1

 

Data Terminal Ready (UART1)

38

 

GPIO11

 

DCD1

 

Data Carrier Detect (UART1)

40

 

GPIO12

 

CTS1

 

Clear To Send (UART1)

All general purpose IO (GPIO) is programmable by the user. Some GPIO has alternate functionality already associated with it; this is indicated in the default column. GPIO which has alternate function is effectively multiplexed, so that the user chooses through AT commands the appropriate configuration for their application.

GPIO is programmable for the following features:

•An input or output

•Level-sensitive or transition-sensitive

•Open drain or direct drive

•Polarity (inversion)

•Internal pull-up resistors

If pins labeled in the table above are not being used for the indicated alternative function they may be used as general purpose inputs or outputs; they are not constrained to work in only one direction. All GPIO is level shifted on the GR64, and has the characteristics defined in paragraph 5.3.1.

GPIO has a number of sharing (configuration) options. Sharing means that it is not feasible to operate all the alternative features concurrently, however, with care, dynamic switching from one feature to another is possible.

Users should note that if flow control is required for UART1 then GPIOs 7 to 12 inclusive cannot be configured for general purpose use.

LZT 123 1834

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