AnsweredAssumed Answered

SPI change polarity on the fly

Question asked by Mancini.Michele on Aug 22, 2012
Latest reply on Aug 23, 2012 by Clive One
Hi, I want change polarity on the fly example

When I setting the SPI master, I setting "SPI_CPOL_Low" trasmit the 16 bit data, and work!
But I need recive another 16bit data with polarity inverse  "SPI_CPOL_Hight"

The protocolo is this: (ADF7021 "Serial Interface Readback Timing Diagram") Send screen of datasheet:
Send 32bit + 1bit clock + 16 bit clock with inverse polarity
Send 32bit = Ok
but How to send in the fly 1 bit clock and inverse polarity on the fly?

  /* SPI configuration -------------------------------------------------------*/
  SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
  SPI_InitStructure.SPI_DataSize = SPI_DataSize_16b;
  SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;
  SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;
  SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
  SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_32;
  SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
  SPI_InitStructure.SPI_CRCPolynomial = 7;
  SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
  SPI_Init(SPI1, &SPI_InitStructure);
  /* Enable the SPI peripheral */