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Issue in reading the EEPROM data via SPI

NC.1
Associate

Hi,

We are using MPC5xxx uC and configured single SPI channel for 3 different devices.

One of the device is EEPROM (M95256-DRE) and SPI channel is configured as 'Synchronous' mode.

Issue :

Before configuring the SPI channel for EEPROM, the two devices were able to successfully get the transmit / receive the data via SPI channel.

We tried testing the EEPROM independently and we were able to read / write the data from / to EEPROM successfully (Here the other two devices functionality was disabled).

When all the 3 devices functionality is enabled, we observed the below issue :

Scneario 1 : When EEPROM alone is requested to transmit the data we are able to receive the data from EEPROM.

Scneario 2 : Sequentially we are utilizing the SPI channel to get the data from EEPROM and other devices in below mentioned sequence.

Step 1 : Send command to get the data from EEPROM. Here we are getting correct data.

Step 2 : Send command to get the data from other devices. Here we are getting correct data.

Step 3 : Send command to get the data from EEPROM . Here we are getting zero value from EEPROM but the request is transmitted successfully.

From the above observation we have a query that whether EEPROM needs a dedicated SPI channel.

Could you please answer the above mentioned query and help us resolve the above mentioned issue at the earliest.

Thank you.

1 REPLY 1
Pierre P.
Senior III

Hello,

Yes i recommend a dedicated SPI channel for the EEPROM. (At least /S line)

Note: Step 3 seems to be corrupted by data transmitting from other devices.

Best Regards

Team EEPROM suPPort