topic S32K312 SPI+DMA in S32K

S32K312 SPI+DMA

sergiverdaguerelausa — Mon, 31 Jul 2023 11:29:43 GMT

Hi all,

I have an SPI working at 4.8bps using DMA. The issue is that during transmission, gaps of 3.3us appear between bytes:

sergiverdaguerelausa_0-1690802553552.png

The SPI clock should work at 80MHz, and the DMA at 160MHz, so I don't understand why this delay appears between bytes.

Configuration:

sergiverdaguerelausa_1-1690802553571.png

sergiverdaguerelausa_2-1690802553580.png

sergiverdaguerelausa_3-1690802553603.png

sergiverdaguerelausa_4-1690802553641.png

Code:

/* Initalized clock */
Clock_Ip_Init(&Clock_Ip_aClockConfig[0]);

/* Initalized pin */
Siul2_Port_Ip_Init(NUM_OF_CONFIGURED_PINS0, g_pin_mux_InitConfigArr0);
/* Initialize interrupt */
IntCtrl_Ip_Init(&IntCtrlConfig_0);
IntCtrl_Ip_ConfigIrqRouting(&intRouteConfig);

/* Initialize DMA IP} Driver */
(void)Dma_Ip_Init(&Dma_Ip_xDmaInitPB);

/* Initalized spi using instance lpspi as a spi master */
Lpspi_Ip_Init(&Lpspi_Ip_PhyUnitConfig_SpiPhyUnit_0_Instance_0_BOARD_InitPeripherals);

/* Master transmits data by async method with DMA */
Lpspi_Ip_AsyncTransmit(&MASTER_EXTERNAL_DEVICE, u8_frame_reset, NULL, sizeof(u8_frame_reset), spi_callback);

I am using S32K312EVB-Q17

Thank you in advance!

Sergi

Re: S32K312 SPI+DMA

Robin_Shen — Tue, 01 Aug 2023 02:47:44 GMT

Hi Sergi,

Would you please decrease the value of SpiTimeClk2Cs SpiTimeCs2Clk SpiTimeCs2Cs and measure the waveform again?

SpiTimeClk2Cs SpiTimeCs2Clk SpiTimeCs2Cs.png

If still not work, please let me know the version of S32DS\S32K3 RTD, or attached your test project.

Best Regards,
Robin
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Re: S32K312 SPI+DMA

sergiverdaguerelausa — Tue, 01 Aug 2023 05:46:22 GMT

Hi Robin,

Thank you very much. I attach an screenshot with the new timmings:

sergiverdaguerelausa_0-1690868811570.png

And the new configuration:

sergiverdaguerelausa_1-1690868849815.png

Now works as I expected.

Bes regards,

Sergi