Led Driver On Gpio[5]; Figure 30.5. Gpio[5] Led Driver Block Diagram - Silicon Laboratories Si4010-C2 Manual

30.6. LED Driver on GPIO[5]

For application mode the GPIO[5] is shared with LED current driver. The LED current driver provides three
levels of LED current, 1mA maximum. The current levels are described in SFR Definition 30.6. User can
set the current intensity and then control the LED on and off by P0.5, port P0 bit 5, as a regular output.
There is no need to modify the P0CON.5 bit, since the GPIO[5] output driver is set to be open drain. When
the LED driver is on by setting the P0.5=1 then the pulldown output transistor is disabled. The GPIO[5] is
used as a regular open drain output during the C2 debugging sessions only.
During the C2 debug sessions the IDE will forcibly disable the LED driver so the LED drive will not interfere
with the debugging session. There will be an option on IDE to disable the "LED disable", but it will have to
be used with caution.
When the user hits Disconnect button on the IDE then the IDE clears all breakpoint, removes the LED dis-
able, and runs the application from the point where it was halted. Then the application will control the LED.
The user then can hit the Connect button on the IDE to connect to the chip again. For the IDE to be able
to connect to the chip the LED must not be driven (not lit).

Figure 30.5. GPIO[5] LED Driver Block Diagram

VDD
50k
2
PORT_CTRL
Rev. 1.0
Si4010-C2
VDD
GPIO[5]/LED
Debug LED disable
P0
117