MPC5xxx中的主题 Only one register can read data when using MPC5744P

Only one register can read data when using MPC5744P

bruceye — Sun, 04 Jun 2017 03:29:57 GMT

Hi everyone,

There are 4 SPI registers in the MPC5744P : SPI0 -SPI4 .When communicating with another chip using master mode , I found that only one SPI register (SPI2) was able to receive and read data from the slave chip .For other 3 registers , correct waveform can be observed by the oscilloscope on the SCK、SDO、SIN and CS pins ,and they have the same SPI timing as SPI2 register , but the received data of these three registers were awlays 0 .

Meanwhile , SPI2 register has 2 pins of SIN --A[2] and A[13] ,I found that only use A[2] as the SIN can read the received data ,using A[13] has the same problem as described above.

Is there some specific configuration for specific SPI registers or I missed something when Configure the SPI register? I want to know the reason why in the same configuration, only a SPI register can communicate properly?

Hoping for your help.

Thank you sincerely.

Bruce

Re: Only one register can read data when using MPC5744P

davidtosenovjan — Mon, 05 Jun 2017 17:31:19 GMT

Hi, do you have properly setup particular SIU_IMCR register? IMCR register says how to route signal from particular input buffer to particular module (thus it is input configuration).

Re: Only one register can read data when using MPC5744P

bruceye — Tue, 06 Jun 2017 03:22:29 GMT

Hi David,

Thank you for your reply. I am not sure whether I have setup particular SIU_IMCR register properly.

Taking DSPI_2 SIN for example .

First I use A2 pin as the SIN ,so my program statement is ：SIUL2.IMCR[47].B.SSS = 2; //A2 as SIN of DSPI2.

Then program works well and I can read the received data.

However ,when I changed to use A13 pin , I changed the statement to :SIUL2.IMCR[47].B.SSS = 1; //A13 as SIN of DSPI2.

Then I can only receive 0 after debugging.

So did I make some mistakes when change the statement? Could you please tell me where might be my problem ?

Thank you

Bruce

Re: Only one register can read data when using MPC5744P

davidtosenovjan — Tue, 06 Jun 2017 06:22:27 GMT

Also, do you have enable input buffer for A13 pin (SIUL2_MSCR13[IBE])?

Re: Only one register can read data when using MPC5744P

bruceye — Wed, 07 Jun 2017 02:28:24 GMT

Hi David,

Thank you for your guide, just like you said , I did not enable the input buffer for A13 .Now the SPI works well.

Thank you agin.

Bruce