Problem SSP Master

[mt-i-euk]

Posted on October 24, 2006 at 13:10

Problem SSP Master

[mt-i-euk]

Posted on May 17, 2011 at 09:33

Hi,

i´m tryinig to communicate over the SSP interface. I´ve tried the SSP example from ST and it works fine, but i can receive data even if there ist no connection between the MOSI and MISO PINs. The Data are given out on the MOSI Pin, but if I put the pin to ground i receive the sent data too. There must be a bug in the receive register. Has anyone an idea why?

Here´s my code:

/* SSP0 configuration */

SSP_DeInit(SSP0);

SSP_InitStructure.SSP_FrameFormat = SSP_FrameFormat_Motorola;

SSP_InitStructure.SSP_Mode = SSP_Mode_Master;

SSP_InitStructure.SSP_CPOL = SSP_CPOL_High;

SSP_InitStructure.SSP_CPHA = SSP_CPHA_2Edge;

SSP_InitStructure.SSP_DataSize = SSP_DataSize_8b;

SSP_InitStructure.SSP_ClockRate = 5;

SSP_InitStructure.SSP_ClockPrescaler = 2;

SSP_Init(SSP0, &SSP_InitStructure);

/* SSP0 enable */

SSP_Cmd(SSP0, ENABLE);

for(k=0; k

SSP0_Buffer_Rx[k] = SSP_ReceiveData(SSP0);

Tx_Idx=Rx_Idx=0;

/* Slave to master transfer procedure */

while(Tx_Idx

{

SSP_SendData(SSP0, SSP0_Buffer_Tx[Tx_Idx++]);

while(SSP_GetFlagStatus(SSP0, SSP_FLAG_RxFifoNotEmpty)==RESET);

SSP0_Buffer_Rx[SSP0RxBufferControl++] = SSP_ReceiveData(SSP0);

}

greeni :-W [B]

[tomas23]

Posted on May 17, 2011 at 09:33

Check SSPx->CR1 register, bit 0, Loopback mode, even the library.

[truf9]

Posted on May 17, 2011 at 09:33

Hello,

look on the discussion from 27.09.2006.

If you use an SPI-Master, the NSS-Pin must be tied to VCC