在PIC16LF1709上映射到RA3的RXPPS不起作用？

嗨，伙计们，我正在与PIC16LF1709作斗争，我在端口引脚RA3上映射了USART RX，这是/MCLR输入。在配置字中，我定义MCLR作为数字输入。在固件中，我将RA3上的上拉设置为活动的，并且RA3映射为RX输入：我可以通过TX发送字符，但是接收不是一个选项。但是当我在RX上映射RA4：字符确实进来了。所以我怀疑数据表中有一个缺陷。RA3不能用于PPS吗？PPS1WAY是ON，但是PPSLOCKED从未设置（在上面发布的initSerialPort()函数中只清除一次）。我想在RA3上映射RX的原因是，我使用programheader作为串行端口的连接器，由我编写的引导加载程序使用（在MCLR管脚1（RA3）上的RX和ICSPD管脚4（RA0）上的TX）。有什么建议吗？谢谢你的帮助



      以下为原文

    Hi Guys,

I'm struggling with a PIC16LF1709 where I mapped the USART RX on portpin RA3, which is the /MCLR input. In the config words I define MCLR as a digital input. In the firmware I make the pullup on RA3 active and is RA3 mapped as RX input:
void initSerialPort(void) {
  PPSLOCK=0x55;
  PPSLOCK=0xAA;
  PPSLOCKbits.PPSLOCKED = false;
  RXPPS = 0b00000011; // = Peripheral input is RA3
  RA0PPS = 0b00010100; // RA0 source is TX/CK
  BAUD1CON = 0x08; // BRG16=1
  SPBRG = 138; // 57K6
  TRISA0 = 0;
  TX1STA = 0b00100100; // TX enabled, highspeed (BRGH=1)
  RC1STA = 0b10010000; // RX enabled: SPEN=1, CREN=1
  RC1REG;
}
I can send characters through TX, but receiving is not an option. But when I map RA4 on RX:
RXPPS = 0b00000100; // = Peripheral input is RA4
characters do come in. So I suspect a flaw in the datasheet. RA3 cannot be used for PPS ?? PPS1WAY is ON, but PPSLOCKED is never set (only cleared once in the function initSerialPort() posted above).
The reason why I want to map RX on RA3 is, that I use the programheader as a connector for a serial port, used by the bootloader I wrote (RX on MCLR pin 1 (RA3) and TX on ICSPD pin 4 (RA0)).

Any suggestions ?

Thanks in advance

Reini