用28335的mcbsp模拟spi驱动AD7606
这是用自带spi读数据的程序，好使
#define DUMMYDATA 0x5a5a
int16 AD7606_Get_Word(void)
{
int16 rdata;
SpiaRegs.SPICTL.bit.TALK = 0; // 禁止发送功能
SpiaRegs.SPITXBUF = DUMMYDATA;
while(SpiaRegs.SPIFFRX.bit.RXFFST == 0 ) {}; //等待接收数据
rdata = SpiaRegs.SPIRXBUF;
return rdata;
}
这是mcbsp读数据的程序
int16 Mcbsp_Get_Word(void)
{
int16 rdata;
CS_L();
McbspaRegs.DXR1.all= 0x00;
while( McbspaRegs.SPCR1.bit.RRDY == 0 ) {} // Master waits until RX data is ready
rdata = McbspaRegs.DRR1.all; // Then read DRR1 to complete receiving of data
CS_H();
return rdata;
}
用逻辑分析发现，mcbsp模拟spi读出的数据始终是0，根本接收不到数据该怎么解决？有没有像spi一样，可以禁止发送功能的？
以下为mcbsp的配置程序
McbspaRegs.SPCR2.all=0x0000; // Reset FS generator, sample rate generator & transmitter
McbspaRegs.SPCR1.all=0x0000; // Reset Receiver, Right justify word, Digital loopback dis.
McbspaRegs.PCR.all=0x0F08; //(CLKXM=CLKRM=FSXM=FSRM= 1, FSXP = 1)
McbspaRegs.SPCR1.bit.DLB = 0; //为0则禁止回送,为1则使用回送功能
McbspaRegs.SPCR1.bit.CLKSTP = 2; // Together with CLKXP/CLKRP determines clocking scheme 时钟停止模式,有时钟延迟
McbspaRegs.PCR.bit.CLKXP = 0; // CPOL = 0, CPHA = 0 rising edge no delay上升沿发送
McbspaRegs.PCR.bit.CLKRP = 0; //下降沿接收
McbspaRegs.RCR2.bit.RDATDLY=01; // FSX setup time 1 in master mode. 0 for slave mode (Receive)
McbspaRegs.XCR2.bit.XDATDLY=01; // FSX setup time 1 in master mode. 0 for slave mode (Transmit)
McbspaRegs.RCR1.bit.RWDLEN1=2; // 32-bit word RWDLEN1=101 32bit
McbspaRegs.XCR1.bit.XWDLEN1=2; // 32-bit word RWDLEN1=010 16bit
McbspaRegs.SRGR2.all=0x2000; // CLKSM=1, FPER = 1 CLKG periods
// McbspaRegs.SRGR1.all= 0x000F; // Frame Width = 1 CLKG period, CLKGDV=16
McbspaRegs.SRGR1.bit.CLKGDV = 4; // CLKG frequency = LSPCLK/(CLKGDV+1)增加波特率，原先为1不好使
McbspaRegs.SPCR2.bit.GRST=1; // Enable the sample rate generator
delay_loop(); // Wait at least 2 SRG clock cycles
McbspaRegs.SPCR2.bit.XRST=1; // Release TX from Reset
McbspaRegs.SPCR1.bit.RRST=1; // Release RX from Reset
McbspaRegs.SPCR2.bit.FRST=1; // Frame Sync Generator reset
- bit.RXFFST == 0 ) {}; //等待接收数据
- rdata = SpiaRegs.SPIRXBUF;
- return rdata;
- }
京公网安备 11010802033920号
