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Preliminary Rev. 0.4
8.8. GPIO Configuration
Three general purpose IOs (GPIOs) are available. Numerous functions such as specific interrupts, TRSW control,
Microcontroller Output, etc. can be routed to the GPIO pins as shown in the tables below. When in Shutdown mode
all the GPIO pads are pulled low.
Note:
The ADC should not be selected as an input to the GPIO in Standby or Sleep Modes and will cause excess current con-
sumption.
The GPIO settings for GPIO1 and GPIO2 are the same as for GPIO0 with the exception of the 00000 default
setting. The default settings for each GPIO are listed below:
The chip is configured to provide the System Clock output to the microcontroller so that only one crystal is needed
in the system, therefore reducing the BOM cost. For the TX Data Source, Direct Mode is used because long
packets are desired with a unique packet handling format already implemented in the microcontroller. In this
configuration the TX Data Clock is configured onto GPIO0, the TX Data is configured onto GPIO1, and the
Microcontroller System Clock output is configured onto GPIO2.
For a complete list of the available GPIO's see “Register 0Ch. GPIO Configuration 1,” on page 90, “Register 0Dh.
GPIO Configuration 2,” on page 91, and “Register 0Eh. I/O Port Configuration,” on page 92.
Add R/W Function/Des
cription
D7
D6
D5
D4
D3
D2
D1
D0
POR Def.
0B
R/W
GPIO0
Configuration
gpio0drv[1] gpio0drv[0]
pup0
gpio0[4] gpio0[3] gpio0[2] gpio0[1] gpio0[0]
00h
0C
R/W
GPIO1
Configuration
gpio1drv[1] gpio1drv[0]
pup1
gpio1[4] gpio1[3] gpio1[2] gpio1[1] gpio1[0]
00h
0D
R/W
GPIO2
Configuration
gpio2drv[1] gpio2drv[0]
pup2
gpio2[4] gpio2[3] gpio2[2] gpio2[1] gpio2[0]
00h
0E
R/W
I/O Port
Configuration
extitst[2]
extitst[1] extitst[0]
itsdo
dio2
dio1
dio0
00h
GPIO
00000—Default Setting
GPIO0
POR
GPIO1
POR Inverted
GPIO2
Microcontroller Clock
