为什么只有当发送一组奇数值ASCII数据时spi receive才会挂起？

你好，我正在使用SPI在无线ZigBee模块（从机）和PIC18F420（主机）之间进行通信。这里是SPI部分：/*SS_Set()；(len--){unsigned char TempVar;TempVar=SSPBUF；.//Clears BFPIR1bits.SSPIF=0；.//Clear inter.flagSSPCON1bits.WCOL=0；SSPBUF=*pBuf；.//启动SPI bu轮到你了！(PIR1bits.SSPIF)；..//等待，直到“BF”位被设置*pBuf+=SSPBUF；}SS_Clr()；..//Slave Clear(Active.)*/如果接收到奇值ascii数据，SPI代码似乎挂起。例如：无线模块（1）=A.Module（2）+PIC（Master）=B当A向B发送一组数据（“AAA”或“0x41,0x41,0x41”）时，B中实现的代码在接收到两到三组之后似乎挂起。没有任何问题。只有当发送一组奇数值ASCII数据时，它才会挂起。



      以下为原文

    Hello,
I'm communicating between a wireless zigbee module (Slave) and pic18f4520(master) using SPI. Here is the SPI part:

/*
SS_Set();                                                    //Slave Set (Active Low)
while (len--)
{
unsigned char TempVar;
TempVar = SSPBUF;                                    // Clears BF
PIR1bits.SSPIF = 0;                                    // Clear interrupt flag
SSPCON1bits.WCOL = 0;

SSPBUF = *pBuf;                                       // initiate SPI bus cycle
while(!PIR1bits.SSPIF);                               // wait until 'BF' bit is set
*pBuf++ = SSPBUF;
}
SS_Clr();                                                  //Slave Clear (Active Low)
*/

The SPI code seems to hang if an odd-value ascii data is received. For example:

Wireless Module (1) = A
Wireless Module(2)+PIC(Master) = B

When A sends a set of data ("AAA" or "0x41,0x41,0x41") to B, the code which is implemented in B seems to hang after receiving two or three sets.

When A sends a set of data ("BBB" or "0x42,0x42,0x42") to B, it receives continuously without any issues. It only hangs if A sends a set of odd-value ascii data.