Non Volatile RAM (F-RAM & NVSRAM)

For better bus utilization on our system we use 32 bit width, including 32 bit spi transfer. It has the side effect that WEL opcode/command is sent as a 4 byte command which has worked fine in the past, using the FRAM device CY15B104Q. Now that we have changed to FRAM device CY15X108QI it does not work anymore. We have tried to have the WEL opcode first, last or fill all bytes, including having the other bytes as 0s, 1s or 55 which I think was mentioned as idle pattern, nothing makes the WEL latch when using 32 bit transfer. Sending the WEL opcode as a single byte works as expected, but is not how we would preferably do this.

The attached data is captured for the two devices using digital analyzer, and show

1. read status register 0x5
2. set write enable latch 0x6
3. read status register 0x5 again to see if WEL was set or not

CY15B104Q accepting 32 bit transfer for WEL:

CY15B104Q_working

CY15X108QI not accepting 32 bit transfer for WEL:CY15X108QI _not_working

Is it, should it be possible? It worked in the past for other chip? Please advice.

我們使用FM24CL64B-GTR于产品应用。

因为之前是有看到富士通的FRAM的datasheet中是有关于ESD和闩锁方面的说明的，因此想了解下CYPRESS的FRAM是否也有这方面的说明，只是未在datasheet中展示，另外FRAM芯片设计中是否又对闩锁问题在半导体层面做加强处理或工艺加强？

如果FRAM因為ESD發生閂鎖，那對存儲在裡面的資料會有什麼影響?

閂鎖後輕的結果或者嚴重的後果會是什麼?

Dear Support team,

FRAM FM25V10 datasheet mentions that the device specifications are guaranteed over an industrial temperature range of –40°C to +85°C. But under maximum ratings section Ambient temperature range with power applied is mentioned to be –55°C to +125°C. I was wondering whether it is possible to operate this FRAM above 85°C upto 125°C?  Will it behave in the same manner as specified in the datasheet, in this case?

Thanking you in advance.

Hello Community,

Greetings for the day!

Myself Vipul Prajapati working as Sr. Engineer at Eaton India Innovation Center, Pune, India for the Power system division group. This is with reference to get the details of standard bitbang SPI routine sample code to do word write into cypress FRAM - CY15E016Q.

We are currently working for a project which uses NXP Legacy automotive MCU (PN - M68HC16Z1). To support the ongoing firmware development, we would require to write SPI bitbang routine in existing FW which can write word by word data to FRAM chip. As this project is with legacy development, running from last 18 years with very limited MCU support, It would be difficult for us to write SPI routine which can do the job without affecting the existing FW.

Could you please help us to provide the sample SPI routine which can be utilize to write word by word data to FRAM chip CY15E016Q?   Thanks in advance!