industrialNETworX

Hi!

I use the rcx and implemented a spi. My code looks like follows:

CONST FAR RX_SPISLAVE_SET_T atrXSpi[] = {
{ {"SYSSPI",RX_PERIPHERAL_TYPE_SPI,0},
0, /* Bus port 0 */
1, /* Chip select 0 */
RX_SPI_MODE0, /* spi mode 3 */
RX_SPI_SPEED_25_0MHz, /* Speed is 25 Mhz */
0, /* No Burst block support */
0, /* No delay between bursts */
}
};

RX_HANDLE hSpi;
rX_MemAllocateMemory(&hSpi,DRV_SPI_SIZE);
Drv_SpiIdentifySpi("SYSSPI",0,&hSpi);
Drv_SpiInitializeSpi(hSpi);
UINT8 bSendBuf[4] = { 0x44, 0x11, 0x22, 0x88 };
UINT8 bRecBuf[4];

Drv_SpiOpen(hSpi, RX_INFINITE);
Drv_SpiSlaveSelect(hSpi);
Drv_SpiSendReceive(hSpi, 4, bSendBuf, bRecBuf);
Drv_SpiSlaveDeselect(hSpi);
Drv_SpiClose(hSpi);

In princible everything works fine. But the time between the falling edge on CS and the beginning of the data transfer on MOSI is very long (1.8 us) versus the time which is needed for data transfer (1.35 us - 4 bytes). Also the time between end of data transfer on MOSI and the rising edge of CS is very long - 4.2 us.

Is this normal? Do I have made mistakes? Are there any possibilities which can perform a faster data transfer (from falling edge on CS till rising edge on CS)?

Thanks