topic Re: S32K388 SPI Config SJA1105SEL Read Static Area Register Error in S32K

S32K388 SPI Config SJA1105SEL Read Static Area Register Error

Ryan_xjl — Thu, 29 Jan 2026 07:28:02 GMT

Hi, NXP 工程师

当前基于S32K388 MCU SPI0 对SJA1105SEL Static Config(BASE_ADDRESS:0x20000h)，Initi进行如下操作：

1、Read Device ID(BaseAddress:0x00000)，返回(0XAE00030Eh)正确

2.1、通过SJA1105X_CONFIG-GENTOOL\sja1105QS.py 生成HEX File(sja1105QS.HEX) 并通过sja1105_converter.py产生C FIle 服务SPI Write操作

2.2、生成的C File合并到S32K388 操作SJA1105工程中，SPI Write(BASE_ADDRESS:0x20000h)都OK

2.3、SPI Read SJA1105 Config Status Information(address:0x01)，返回值(CONFIGS:BIT31)为1，说明是有效的；

3、当(CONFIGS:BIT31)为1，SPI Read SJA1105 Base Address(BASE_ADDRESS:0x20000h)，发现读取出的数据都为0，理论应该在没有断电情况下，SPI Write 成功并显示配置有效，SPI Read对应Register Data应该是Write的数据，但是当前Read数据为0，不清楚什么情况？

以上数据通过示波器测试数据，波形都是正确

为什么SPI Write成功后再SPI Read，数据怎么是0，多谢给与帮助！

Re: S32K388 SPI Config SJA1105SEL Read Static Area Register Error

PavelL — Thu, 29 Jan 2026 09:10:04 GMT

Hello @Ryan_xjl ,

As it is noted in UM11040 - Software user manual for SJA1105P, SJA1105Q, SJA1105R, SJA1105S, Rev. 3, chapter 4.2 Loading Configuration Data : "The entire configuration area is write-only. A read access to any address in this area returns arbitrary data."

Best regards,

Pavel

Re: S32K388 SPI Config SJA1105SEL Read Static Area Register Error

Ryan_xjl — Thu, 29 Jan 2026 10:15:41 GMT

Hi, PaveIL
Thank you very much for your help！
May I ask a few more questions：
1、Does it mean that static configuration is successful as long as the (CONFIGS: BIT31) flag is 1?
2、I want to try how to configure incorrectly to cause (CONFIGS: BIT31) Flag to be 0. If I don't call the Config function, I just read (CONFIGS: BIT31) Flag and found that Flag=1, so I want to verify it. Thank you

Re: S32K388 SPI Config SJA1105SEL Read Static Area Register Error

PavelL — Thu, 29 Jan 2026 10:46:14 GMT

Hello @Ryan_xjl ,

ad 1. Yes, exactly. However, please notice that CGU needs to be configured as well - refer to chapter Interface configuration in AH1704 - SJA1105PQRS Application Hints. If CGU setting is not included in your python script (usually not), it should be configured by register access.

ad 2. To test your firmware uploading flow, you may try to corrupt/change Global CRC or Device ID in your hex file. Please refer to the UM11040 - Figure 7. Generic Loader Format, to see where Device ID and Global CRC are placed.

Best regards,

Pavel

Re: S32K388 SPI Config SJA1105SEL Read Static Area Register Error

Ryan_xjl — Thu, 29 Jan 2026 13:19:54 GMT

Hi，
Thank you！
ad2. I have verified the same approach (incorrect DEVICE ID) as yours.
ad1. My IC is SJA1105SEL，InitSwitch, does it only require the completion of CGU & STATIC CONFIGURATION，No need to initialize ACU & SGMII，The basic functions of SJA1105 can be realized？

Re: S32K388 SPI Config SJA1105SEL Read Static Area Register Error

PavelL — Fri, 30 Jan 2026 07:46:09 GMT

Hello @Ryan_xjl ,

SGMII doesn't require special CGU settings.

Please check chapter 6.1.14 Slew Rate Settings in AH1704, where recommended ACU settings are discussed.

Best regards,

Pavel

Re: S32K388 SPI Config SJA1105SEL Read Static Area Register Error

Ryan_xjl — Fri, 30 Jan 2026 17:02:08 GMT

Hi,
你好，针对SJA1105，针对从ACU读取并配置CGU，虽然静态Table对Port配置为RGMII，但是从ACU读取状态为RMII，导致CGU配置为RMII，不清楚为什么会这样，可否给些帮助！
Code Ex:
SJA1105P_getPortStatusMiix(&portStatus, port, switchId);
configPort(port, switchId, portStatus.speed, portStatus.xmiiMode, portStatus.phyMode);

Re: S32K388 SPI Config SJA1105SEL Read Static Area Register Error

PavelL — Mon, 02 Feb 2026 08:14:16 GMT

Hello @Ryan_xjl ,

getPortStatusMiix() does not return the xMII mode from your static configuration. It returns the runtime electrical mode detected by the ACU/CGU. If the CGU clock paths are still in their default state (e.g., RMII reference clock active), the ACU will classify the port as RMII, even if the static “xMII Params” table says RGMII.
In your code, you then pass this runtime RMII status directly into configPort(), which means your application overwrites your intended RGMII configuration with RMII at runtime.

Best regards,

Pavel