Hi,
According to the errata, PB0 and PB1 has the following issue:
Tiva
C Series TM4C129x Microcontrollers Silicon Revisions 1, 2, and 3
GPIO#09 In Some Cases, Noise Injected Into GPIO pins PB0 and PB1 can Cause High
Current Draw
Revision(s) Affected: 1, 2, and 3.
Description: A fast transition on either PB0 or PB1 can switch on a low resistance path between one
or both pins and ground potentially causing a high current draw.
This condition has been observed when the signal at the device pin has a rise time or
fall time (measured from 10% to 90% of VDD) that is faster than 2 ns. The condition is
more likely to occur at high temperatures or in noisy environments. It can occur when the
pin is in input or output mode or with any pin multiplexing options.
If the condition is induced while the pin is configured as an output GPIO, then changing
the pin state to low and then returning it to a high state at a lower temperature will
resolve the condition.
Workaround(s):
1. Do not use PB0 and PB1. Connect both to GND through a 1 kΩ resistor and
configure them as GPIO inputs.
2. If PB0 and PB1 are used as USB0ID and USB0VBUS, refer to the USB section of
SPMA056, System Design Guidelines for the TM4C129x Family of Tiva C Series
Microcontrollers, and confirm all guidelines contained in the document are followed.
We are planing to use this two pins for CAN1 signals. Is there any concern we should take into account?
Thanks
Tianlei
