Hi, Iam using a m95080 eeprom IC. Iam not able to read any data from it.

[PTiwa]

Hi, Iam using a m95080 eeprom IC. Iam not able to read any data from it. Foolowing are the steps iam doing:

1) Doing a low on chip select.

2) Sending a Write enable instruction to ic(0x06).

3) doing a high on chip select.

(This should set the write enable latch in the status register WEL bit)

4) Doing a low on chip select again

5) Writing a read status register instruction on ic(0x05).

6) Sending a few dummy bytes (0x00) for proving clocks to slave for data transfer.

But on the MISO line I can only observe the data I'm sending on MOSI line i.e. 0x06 and 0x05 and then its all zero.

All these observations are on an oscilloscope.

The clock I'm using is below 4 Mhz. SPI mode used is CPOL = 1 and CPHA = 1. Sending MSB first from SPI.

[Pierre P.]

​Hello,

-Did you wait for 5ms between step 3) and 4) ?

It's an abnormal situation to have same data on MISO & MOSI line. MISO line should be Hi-Z during the instruction transmission.

EEPROM SuPPort Team​

[PTiwa]

Hi,

Yes I tried by giving a delay of millisecond between step 3 and 4 but still getting the same data(the data I sent on MOSI line 0x06 and 0x05) on MISO line

[Pierre P.]

​delay should be 5ms.

please check your connection MOSI/MISO

[PTiwa]

As I mentioned I tried with 5 millisecond delay. The steps that I mentioned above are in correct order right or should I change something in there?

I will check the connections. Thanks a lot for your response.

[S.Ma]

There is an st eeprom x nucleo shield with example code on stm32. Dig?

[PTiwa]

Ya actually I looked into it. But I was trying the very basic instructions on the eeprom IC first just to make sure its working fine and the connections are all intact.

Thanks.

[Andreas Bolsch]

The EEPROM (as any other SPI flash) never echoes the commands received via MOSI to MISO. So if you do see the command on both MOSI and MISO, either the EEPROM is defective (but even then it's rather unlikely you will observe that echo) or you've accidentally shorted (physically or logically) MOSI and MISO lines.

[PTiwa]

That's correct. I will check on the IC and the connections. Thanks a lot for your response.