MSP432E401Y: Trouble using pin 128

Daniel Nanto

Part Number: MSP432E401Y
Other Parts Discussed in Thread: MSP-EXP432E401Y

Hello,

Recently, I used the MSP432E401Y in a new product design. Every function works properly, apart from pin 128 on GPIO port D. Every pin seems to operate as expected (this port is sending parallel data to a display), apart from pin 128.

I decided to import an example project as a sanity check. I imported the basic timerled example for FreeRTOS & CCS Ti compiler, and instructed pin 128 (PD7) to toggle every second. I am watching it with an oscilloscope, and it is not toggling properly.

I've tested this on my custom board where pin 128 is accessed directly, and on 3 of the MSP-EXP432E401Y LaunchPads. Is this the expected behavior? I'm struggling to see anything addressing this in the documentation.

Is it an issue with my syscfg file? The syscfg believes that it is configuring for a launchpad.

Thank you for your help,

Dan

over 1 year ago

+1 Charles Tsai over 1 year ago

TI__Guru**** 191296 points

Hi,

Please refer to the TRM for description on PD7 pin as well as other special pins. These pins are locked by default. You need to unlock them in order to reprogram them.

Before you repurpose PD7, you need to unlock them first with the below instructions.

HWREG(GPIO_PORTD_AHB_BASE+GPIO_O_LOCK) = GPIO_LOCK_KEY;
HWREG(GPIO_PORTD_AHB_BASE+GPIO_O_CR) |= GPIO_PIN_7;

0 Charles Tsai over 1 year ago in reply to Charles Tsai

TI__Guru**** 191296 points

This post will also help. https://e2e.ti.com/support/microcontrollers/msp-low-power-microcontrollers-group/msp430/f/msp-low-power-microcontroller-forum/738949/rtos-msp432e401y-pull-up-down-not-working-on-pd7

0 Daniel Nanto over 1 year ago in reply to Charles Tsai

Intellectual 290 points

Thank you very much! That worked perfectly.

Just for anybody else that may run into this issue, I used the following code (in this order) to make it work:

#include "ti/devices/msp432e4/driverlib/inc/hw_gpio.h"

MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
HWREG(GPIO_PORTD_BASE + GPIO_O_LOCK) = GPIO_LOCK_KEY;
HWREG(GPIO_PORTD_BASE + GPIO_O_CR) |= GPIO_PIN_7;

GPIO_init();

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MSP432E401Y: Trouble using pin 128