S32K312 SPI+DMA

[sergiverdaguerelausa]

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

[Robin_Shen · Accepted solution]

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
-------------------------------------------------------------------------------
Note:
- If this post answers your question, please click the "Mark Correct" button. Thank you!

- We are following threads for 7 weeks after the last post, later replies are ignored
Please open a new thread and refer to the closed one, if you have a related question at a later point in time.
-------------------------------------------------------------------------------

[sergiverdaguerelausa]

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