Non Volatile RAM (F-RAM & NVSRAM) Forum Discussions

Hello,

I am currently developing software for CY15FRAMKIT-002 with a STM32F7 Nucleo Board. I was able to read the Device ID (RDID, command 9Fh) as 0000000006825150 in SPI mode and perform a write to and read from the memory successfully. Now, I configured the device to QPI mode with the following settings in the following sequence:

1. Set the Memory Latency to 0x2 by setting bits 7:4 in Configuration Register  1

2. Set the Register Latency to 0x2 by setting bits 7:6 in Configuration Register  5

3. Enabled QPI mode by setting bit 6 in Configuration Register  2

Once in QPI mode, I tried reading the Device ID (RDID, command 9Fh) but always got the response as 8888888888888888. When I tried to read and write the memory in QPI mode, that seems to work successfully. Then why does the Device ID command not repond with the correct value when it is a supported command in QPI mode? Is this an issue with the GPIO state for IO3 pin or something else? For information, my GPIO pin states are set as below for the STM32:

nCS: NOPULL
SCK: NOPULL

IO0: NOPULL

IO1: NOPULL
IO2: NOPULL
IO3: NOPULL

If this is a GPIO pin state issue, I would wonder why my read and writes work in QPI mode with the set latency. 

Regards,
Surabhi

Hello
We are using FRAM CY15B104QI memory in our project. We are using MSP430FR5994 microcontroller and we want to communicate with FRAM using SPI. 

We have an issue with accessing the memory. We tried to read status register but we did not get expected values on MISO pin (MISO pin did not change its state at all).  We made it work once but after that the same code did not work and we do not know what can be the issue.

I attached the archived  image of workig example (the only one when we get the expected response). I also attached 2 screenshots of the signals on CS, CLK and MOSI that we measured using an osciloscope. 

Are there any known issues with the memory or has this occurred to someone else?

Best regards