topic Re: MPC5744P Non-Volatile RAM in MPC5xxx

MPC5744P Non-Volatile RAM

juliusjai — Mon, 28 Jan 2019 08:56:37 GMT

Hi,

I would like to implement a non-volatile RAM for MPC5744 MCU project. I need to retain some data when MCU goes to reset.

But according to MCU application note - MPC5744P_Software_Start_Up_and_Optimization.pdf:

3.7 SRAM initialization

The internal SRAMs feature Error Correcting Code (ECC). Because these ECC bits can contain random data after the device is turned on, all SRAM locations must be initialized before being read by application code.

Does anybody has an idea on how to implement non-volatile RAM? Or how I can retain some values in RAM when reset occurred?

P.S. I don't want to store these data in data flash.

Thanks in advance.

Julius

Re: MPC5744P Non-Volatile RAM

davidtosenovjan — Tue, 29 Jan 2019 15:56:25 GMT

Hi, you can omit SRAM initialization for Functional reset sources. When a 'functional' reset event occurs, a
partial reset sequence is applied to the chip starting from PHASE1[FUNC], keeping the system memory
content preserved.

Re: MPC5744P Non-Volatile RAM

juliusjai — Mon, 04 Feb 2019 08:53:40 GMT

Thanks David. Appreciated.

Re: MPC5744P Non-Volatile RAM

juliusjai — Mon, 04 Feb 2019 08:54:41 GMT

Thanks David. Appreciated.