PIC24FJ256GA705 UART中断不起作用

大家好！我们正在使用PIC24FJ128GA310代码编程PIC24FJ256GA705处理器（在最后一个PIC中工作得很好）。我们研究了两个不同的问题：1。PIC只是使用UART2模块的TX.2打印一些字符串。PIC使用UART2模块的RX接收字符并使用相同的U2 MODUL的TX打印回原件PIC24FJ128GA310：对于第一个问题，由于我们没有解决的UTXBF的一些问题，以前的代码在新的处理器中不起作用。在代码发送5个字符之后，UTXBF永远保持完整（UTXBF＝1）。我们通过将代码更改为以下代码来解决这个问题：这个代码对于TX来说是很好的。在第二个问题中，我们还没有设法使它工作。我们尝试使用与第一种情况相同的方法：不使用RX中断。但不幸的是，我们没有收到任何字符。使用的代码如下：有人知道为什么中断在我们的情况下不起作用吗？我们想使用它们，但不是强制性的。否则，有人知道如何使用UART而不需要RX和TX中断吗？提前感谢。



      以下为原文

    Hi everyone!

We are programming a PIC24FJ256GA705 processor using PIC24FJ128GA310 code (which works fine in this last PIC).

We have studied two different problems:
1. The pic just prints some strings using UART2 module's TX.
2. The pic receives characters using UART2 module's RX and print them back using the same U2 modul's TX.

Original code for pic24fj128ga310:

void InitUART2(void)
{

U2MODEbits.UARTEN = 0;

        U2BRG = 102;

IFS1bits.U2TXIF = 0; // Clear the Transmit Interrupt Flag
IEC1bits.U2TXIE = 1; // Enable Transmit Interrupts
IFS1bits.U2RXIF = 0; // Clear the Recieve Interrupt Flag
IEC1bits.U2RXIE = 1; // Enable Recieve Interrupts

U2MODEbits.UARTEN = 1;
U2STAbits.UTXEN = 1;
}

int putU2(int c)
{
    while (U2STAbits.UTXBF);
    U2TXREG = c;
    return c;
}

void __attribute__ ((interrupt, no_auto_psv)) _U2RXInterrupt(void)
{
     IFS1bits.U2RXIF = 0;
     volatile int data;
   
    do
    {
        data = U2RXREG;
    } while (U2STAbits.URXDA != 0);
    putU2(data);
}

void __attribute__ ((interrupt, no_auto_psv)) _U2TXInterrupt(void)
{
IFS1bits.U2TXIF = 0;
}
For the first problem, this previous code does not work in the new processor due to some problems with UTXBF that we didn't manage to solve. After the code sends 5 characters, the UTXBF stays full (UTXBF = 1) forever.

We have solved this issue by changing the code to the following one:
U2STAbits.UTXISEL1 = 1;
...
IFS1bits.U2TXIF = 0;
IEC1bits.U2TXIE = 0;
...

int putU2(int c)
{
    while (!_U2TXIF); // wait while Tx buffer full
    U2TXREG = c;
    _U2TXIF = 0;
    return c;
}

This code works fine for TX.

In the second problem, we haven't manage to make it work. We have tried to use the same approach as we did in the first case: not using interruptions for RX. But unfortunatly we do not receive any character.

The used code is the following:

U2STAbits.UTXISEL1 = 1;
...
U2STAbits.URXISEL = 2;
...
IFS1bits.U2TXIF = 0;
IEC1bits.U2TXIE = 0;
IFS1bits.U2RXIF = 0;
IEC1bits.U2RXIE = 0;
...
int putU2(int c)
{
    while (!_U2TXIF); // wait while Tx buffer full
    U2TXREG = c;
    _U2TXIF = 0;
    return c;
}

char getU2()
{
    while(!U2STAbits.URXDA); //option 1
    //while(!_U2RXIF); //option 2
    _U2RXIF = 0;
    putU2(U2RXREG);
    return U2RXREG;
}


Does anybody knows why interruptions do not work in our case? We would like to use them, but is not mandatory. Otherwise, does anybody knows how to use the UART without RX and TX interruptions?

Thanks in advance.