[Wio 3G] PB_7 (RXD) cannot be used for Serial

[toyowata]

Description

The code blow crashed at runtime on Seeed Wio 3G target.

#include "mbed.h"

DigitalOut GrovePower(PB_10, 1); // Grove VDD power enable
Serial device(TXD, RXD, 115200);

int main(void) {
    while (1) {
        wait(0.5);
    }
}

The crash log:

++ MbedOS Error Info ++
Error Status: 0x80010130 Code: 304 Module: 1
Error Message: pinmap not found for peripheral
Location: 0x8000891
Error Value: 0xFFFFFFFF
Current Thread: Id: 0x2000179C Entry: 0x8001EDF StackSize: 0x1000 StackMem: 0x200017E0 SP: 0x200026D8 
For more info, visit: https://armmbed.github.io/mbedos-error/?error=0x80010130
-- MbedOS Error Info --

The TXD and RXD are defined here:

mbed-os/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/TARGET_WIO_3G/PinNames.h

Lines 177 to 178 in d962581

	TXD = PB_6,
	RXD = PB_7,

And there is a PB_6 in PinMap_UART_TX structure, but a PB_7 in PinMap_UART_RX is commented out:

mbed-os/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/TARGET_WIO_3G/PeripheralPins.c

Line 215 in d962581

{PB_6, UART_1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART1)},

mbed-os/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/TARGET_WIO_3G/PeripheralPins.c

Line 234 in d962581

// {PB_7, UART_1, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF7_USART1)}, // (pin used by LED2)

Issue request type

[ ] Question
[ ] Enhancement
[x] Bug

cc @ARMmbed/team-seeed

[ciarmcom]

Internal Jira reference: https://jira.arm.com/browse/MBOCUSTRIA-291