hello everyone:
now,I'm trying to read the device ID of SJ1105P，But the data that comes out is 0xffffffff.I would like to confirm the following questions：
1、If you want to activate the SJA1105P, Should the rsn_p pin be set high first？
2、How long does the CLK signal need to be delayed after the transmission ends? Is there any mandatory?
3、How long does it take to delay the chip selection signal after it is valid?s there any mandatory?
I set the baud rate to 10Mhz, the SPI mode was set to SPI MODE 1, and RST_N the pin was set high directly when it was initialized. Is there anything else I need to pay attention to in the SPI port configuration?Here's my port configuration：
Hello @KUN1996 ,
I apologize I do not have experience with EB Tresos - so I can't help you directly.
But, all SPI requirements are included in SJA1105PQRS Data Sheet rev 2, mainly on Table 12. Dynamic characteristics:
1. Yes, RST_N shall be pulled high. Then you need to wait typ 329us.
2. 3. They covered by Table 12.
The SPI needs to be setup to CPOL = 0 and CPHA = 1 - Serial Peripheral Interface - Wikipedia.
Another source of information is UM11040 - Software user manual for SJA1105P, SJA1105Q, SJA1105R, SJA1105S . Both documents are in Secure Files.
Here are SPI signals when device ID is being read from SJA1105Q by S32K344 on White Board:
Best regards,
Pavel
I used a logic analyzer to check my program and it looks like this. 12 for CLK, 13 for SDI, 14 for SDO, 15 for ss, my SDI send level looks different from yours, do I need to reset the SDI?
This is my receive function：Is the address of this function formatted correctly? Is it possible to write only the address instead of adding 7 additional pieces of data?
Here's my initialization function, where the RST_N pin is set low first, then set high after a delay of 50 us, and then a delay of 329 us Is there an error with my delay?
