c - PIC32 UART 未接收数据

Question

我正在使用 PIC32MX250F128D 构建一个设备。其中一个系统需要使用 UART。从 PIC 传输到 putty 终端效果很好。但是，向另一个方向发送数据不起作用，我没有主意。我使用的是使用 CP2102 芯片的廉价 USB-UART 适配器。 Link if relevant我使用引脚 25 和 26(RPC0/AN6 和 RPC1/AN7)作为 UART。

• 如果 TXEN 传输启用，则在 putty 中输入的所有字符都会返回并打印在 putty 上。即使 RX 和 TX 线交换，也会发生这种情况。 PIC 上的发送中断标志被触发
• 如果 TXEN 发送使能关闭，则 putty 不会打印任何字符。同样，交换电线后也会出现相同的行为。无中断标志。
• 断开 RX 或 TX 线也会导致对 putty 没有回复。
• 使用调试器检查 URXDA RX 缓冲区数据标志，我发现无论设置如何，发送的任何内容都不会放入 RX 缓冲区中。
• UART 环回未启用。运行时也用调试器检查了这一点。
• 放入一个代码循环来写入 TXREG 按预期工作，将字符打印到 putty。
• 常规代码从不与 TXREG 或 RXREG 交互。目前，我们的程序中未使用 TX，RXREG 仅在中断例程中进行处理，由于 RXIF 甚至 URXDA 曾经被标记，因此永远不会被调用。

简而言之，断线、TXEN 禁用和 TX IF 似乎表明这不是硬件或连接问题，并且 PIC 实际上正在镜像其接收的数据。然而，PIC永远不会意识到它接收了数据，没有镜像数据的代码，也没有启用环回。

我的UART相关设置代码如下。我正在使用许多外围设备，因此我还在底部包含了整个设置代码，以防问题出在外围设备冲突上。

//includes
#include <xc.h>
#include <strings.h>
#include <stdio.h>
#include <sys/attribs.h>//necessary for Interrupt declarations

//configuration
#pragma config IOL1WAY = OFF//allows multiple(?) Peripheal cnfigurations
#pragma config FNOSC = FRCPLL//use 8MHZ FRC with PLL as clock
#pragma config FPLLIDIV = DIV_2//PLL input = 4MHZ
#pragma config FPLLMUL = MUL_24//PLL output=96 MHZ
#pragma config FPLLODIV = DIV_2//48 MHZ Sysclock
#pragma config FPBDIV = DIV_2//24 MHZ peripheal Bus
#pragma config FWDTEN=OFF, CP=OFF, BWP=OFF, OSCIOFNC = ON
#pragma config JTAGEN = OFF         // Disable JTAG

void setup_pps(void)         
 {         
     //asm volatile ("di");//disable all interrupts
     SYSKEY = 0x0;         
     SYSKEY = 0xAA996655;         
     SYSKEY = 0x556699AA;         

     CFGCONbits.IOLOCK = 0;         
     U1RXRbits.U1RXR = 0b0110; // Set U1RX to RPC1         
     RPC0Rbits.RPC0R = 0b0001; // Set U1TX to RPC0
     CFGCONbits.IOLOCK = 1;  

     SYSKEY = 0x0;
     //asm volatile ("ei");//re-enable interrupts
 }

void setup(void)
{
    asm("di");//disable interrupts while performing setup
    //Interrupt vector priorities

    IPC8CLR = 0x0000001F;         // clear priority/subpriority fields 
    IPC8SET = 0x0000000C;         // set UART priority = 3, IPC8<4:2>
    IPC8SET = 0x00000000;         // set UART subpriority = 0, IPC8<1:0>

    INTCONbits.MVEC = 1;//enable multivector interrupts

    //***Pin Setup
    setup_pps();
    //**Digital GPIO Setup
    //set all port pins to digital
    ANSELA=0x0;
    //Set all port pins to output
    TRISA=0x0;
    //SNIP
    //## End Digital GPIO Setup

    //** UART Setup
    U1MODEbits.UEN=0b00;//Use only U1TX and U1RX pins
    U1MODEbits.BRGH=1;//TODO:Determine Baud rate for Reach//note: non-highspeed takes multiple samples->probably better for noise
    U1MODEbits.PDSEL=0;//TODO: Reach parity and data select
    //U1MODEbits.RXINV=1;
    U1STAbits.UTXISEL=0;//Transmit Interrupt type
    U1STAbits.URXISEL=0b01;//01;//Receive Interrupt type-Interrupt when 1/2 full (4 bytes)
    int fpb=24000000;
    int baudrate =38400;//change to set baud rate
    U1BRG=fpb/(4*baudrate)-1;//Baud rate Generator//use 16x if brgh=0 
    //IEC1SET=0x0200;//Transmit Interrupt enable/ should not be needed
    IEC1SET=0x0100;//Enable receive interrupt
    U1STAbits.URXEN=1;//Receive Enable
    U1MODEbits.ON=1;//Enable UART
    U1STAbits.UTXEN=1;//Transmit Enable Enable TODO:Determine if needed for reach
    U1STAbits.URXEN=1;//Receive Enable
    //## End UART Setup

   //SNIP

    asm("ei");//re-enable interrupts
    return;
}

整个设置

//includes
#include <xc.h>
//#include <p32xxxx.h>
//#include <proc/p32mx250f128d.h>
#include "letters.h"//codes for 7 segment display
#include "pins.h"//refer to ports/latches by function
#include "other.h"//mainly state machine states
#include <strings.h>
#include <stdio.h>
#include "gps.h"//contains variables and functions of gps data
#include <sys/attribs.h>//necessary for Interrupt declarations
//#include <string.h>//may be used for string manipulation, such as selecting files
//#include <stdio.h>//will be needed for file open

//configuration
#pragma config IOL1WAY = OFF//allows multiple(?) Peripheal cnfigurations
#pragma config FUSBIDIO = OFF//USB ID controlled by port, not USB Module
#pragma config FVBUSONIO = OFF//USB VBUS controlled by port, not USB
#pragma config FNOSC = FRCPLL//use 8MHZ FRC with PLL as clock
#pragma config FPLLIDIV = DIV_2//PLL input = 4MHZ
#pragma config FPLLMUL = MUL_24//PLL output=96 MHZ
#pragma config FPLLODIV = DIV_2//48 MHZ Sysclock
#pragma config UPLLIDIV = DIV_2//4 MHZ USB PLL input
#pragma config UPLLEN = ON//Enable PLL for USB
#pragma config FPBDIV = DIV_2//24 MHZ peripheal Bus
#pragma config FWDTEN=OFF, CP=OFF, BWP=OFF, OSCIOFNC = ON
#pragma config JTAGEN = OFF         // Disable JTAG
#pragma config FSOSCEN = OFF        // Disable Secondary Oscillator

void setup_pps(void)         
 {         
     //asm volatile ("di");//disable all interrupts
     SYSKEY = 0x0;         
     SYSKEY = 0xAA996655;         
     SYSKEY = 0x556699AA;         

     CFGCONbits.IOLOCK = 0;         
     U1RXRbits.U1RXR = 0b0110; // Set U1RX to RPC1         
     RPC0Rbits.RPC0R = 0b0001; // Set U1TX to RPC0
     CFGCONbits.IOLOCK = 1;  

     SYSKEY = 0x0;
     //asm volatile ("ei");//re-enable interrupts
 }

void setup(void)
{
    asm("di");//disable interrupts while performing setup
    //Interrupt vector priorities
    IPC2CLR = 0x001f;         // clear priority/subpriority fields 
    IPC2SET = 0x0018;         // set timer 2 int priority = 6, IPC2<4:2>
    IPC2SET = 0x0000;         // set timer 2 int subpriority = 0, IPC2<1:0>

    IPC5CLR = 0x1f000000;         // clear priority/subpriority fields 
    IPC5SET = 0x10000000;         // set adc int priority = 4, IPC5<28:26>
    IPC5SET = 0x00000000;         // set adc int subpriority = 0, IPC2<25:24>

    IPC7CLR = 0x001F0000;         // clear priority/subpriority fields 
    IPC7SET = 0x00080000;         // set USB priority = 2, IPC7<20:18>
    IPC7SET = 0x00000000;         // set USB subpriority = 0, IPC7<17:16>

    IPC8CLR = 0x0000001F;         // clear priority/subpriority fields 
    IPC8SET = 0x0000000C;         // set UART priority = 3, IPC8<4:2>
    IPC8SET = 0x00000000;         // set UART subpriority = 0, IPC8<1:0>

    IPC8CLR = 0x001F0000;         // clear priority/subpriority fields 
    IPC8SET = 0x00140000;         // set Input Change priority = 5, IPC8<20:18>
    IPC8SET = 0x00000000;         // set Input subpriority = 0, IPC8<17:16>


    INTCONbits.MVEC = 1;//enable multivector interrupts
//    INTEnableSystemMultiVectoredInt();  //Enable multi vector interrupts
  //  INTEnableInterrupts();//enable interrupts



    //Clock Setup
    OSCCONbits.UFRCEN=0; //USE PLL for USB //Hopefully default, otherwise unlock sequence required to write-->move to setuppps

    //***Pin Setup
    setup_pps();
    //DEVCFG0bits.JTAGEN=0;
    //DDPCONbits.JTAGEN = 0
    //**Digital GPIO Setup
    //set all port pins to digital
    ANSELA=0x0;
    ANSELB=0x0;
    ANSELC=0X4;//leave C2/AN8 as analog
    //Set all port pins to output
    TRISA=0x0;
    TRISB=0x0;
    TRISC=0x4;
    //Set Controller Ports to inputs
    TRISBbits.TRISB5=1;
    TRISBbits.TRISB7=1;
    TRISBbits.TRISB8=1;
    TRISBbits.TRISB9=1;
    TRISCbits.TRISC6=1;
    TRISCbits.TRISC7=1;
    TRISCbits.TRISC8=1;
    TRISCbits.TRISC9=1;

    CNCONBbits.ON=1;//enable input change notification of port B
    CNENBSET=0x0180;//enable input change notification on RB7 and RB8 (kill and mode switch) 
    tmp=PORTB;//clear mismatch
    IFS1CLR=0x4000;//clear interrupt flag
    IEC1SET=0x4000;//enable interrupt

    //## End Digital GPIO Setup

    //** UART Setup
    U1MODEbits.UEN=0b00;//Use only U1TX and U1RX pins
    U1MODEbits.BRGH=1;//TODO:Determine Baud rate for Reach//note: non-highspeed takes multiple samples->probably better for noise
    U1MODEbits.PDSEL=0;//TODO: Reach parity and data select
    //U1MODEbits.RXINV=1;
    U1STAbits.UTXISEL=0;//Transmit Interrupt type
    U1STAbits.URXISEL=0b01;//01;//Receive Interrupt type-Interrupt when 1/2 full (4 bytes)
    int fpb=24000000;
    int baudrate =38400;//change to set baud rate
    U1BRG=fpb/(4*baudrate)-1;//Baud rate Generator//use 16x if brgh=0 
    //UxBRG = FPB / (4 * BAUDRATE) - 1//FPB = 24MHZ in current setup
    //IEC1SET=0x0200;//Transmit Interrupt enable/ should not be needed
    IEC1SET=0x0100;//Enable receive interrupt
    U1STAbits.URXEN=1;//Receive Enable
    U1MODEbits.ON=1;//Enable UART
    U1STAbits.UTXEN=1;//Transmit Enable Enable TODO:Determine if needed for reach
    U1STAbits.URXEN=1;//Receive Enable
    //## End UART Setup

    //** ADC Setup
    //Behavior-Samples AN8 8 times automatically, then generates interrupt. Can read samples either in lower or upper half of buffer at a time.
    ANSELCbits.ANSC2=0b1;//Set C2 as analog
    TRISCbits.TRISC2=0b1;//Set C2 as input
    AD1CON1bits.FORM=0b000;//16 bit integer result
    AD1CON1bits.SSRC=0b111;//auto convert at end of sampling
    AD1CON1bits.CLRASAM=0b1;//When interrupt happens, ASAM will automatically be cleared
    AD1CON1bits.ASAM=0b1;//Auto start sampling at conversion end
    AD1CON2bits.VCFG=0b000;//Use AVSS and AVDD as reference
    AD1CON2bits.SMPI=0b1111;//Interrupt every 16th sample
    AD1CON2bits.BUFM=0b0;//Buffer is not split
    AD1CON3bits.ADCS=0b11;//TAD=4*TPB=167ns
    AD1CON3bits.SAMC=0b01111;//Samples for 15 TAD=2.5uS
    AD1CHSbits.CH0SA=0b1000;//Samples AN8
    IEC0SET=0x10000000;//ADC1 INterrupt enable
    AD1CON1bits.ADON=1;//Enable ADC
    //## END ADC Setup

    //**USB Setup
    //TODO
    //## END USB setup

    //###END pin setup

    //***Timer2 setup
    //This will generate an interrupt every 10 ms to change the display.
    T2CONbits.TCKPS=0b101;//1 Timer clock per 32 peripheral bus clocks
    PR2=3750; //Interrupt flag every 10 ms at pbclk=24mhz
    IEC0SET=0x0200;//Timer 2 Interrupt enable
    T2CONbits.ON=0b1;//enable timer

    asm("ei");//re-enable interrupts
    return;
}

Answer 1

我使用 pic32mz，并与外设选择寄存器一起设置引脚方向。类似的东西

//UART2_RXl
TRISCbits.TRISC3 = 1; 
ANSELCbits.ANSC3 = 0;
U2RXR = 0b1100;
//UART2_TX
TRISGbits.TRISG9 = 0; 
ANSELGbits.ANSG9 = 0;
RPG9R = 0b0010;