Model-Based Design Toolbox (MBDT)のトピックRe: Using NVM chip on MPC5775B EVB

Using NVM chip on MPC5775B EVB

sonik82 — Sun, 20 Jun 2021 08:34:50 GMT

I would like to use NVM chip (M95M01-DWMN3TP/K) on DVCU5775EVM, so initially I have prepared simple model just to check chip status.

Chip is connected to SPI0 with CS1

And I have used these settings for SPI blocks

Then have prepared stateflow diagram to send control commands

where Tx_data is control command (RDSR) from M95M01 datasheet

and this command goes after chip is selected

Finally I have got following model.

After flashing, I have used Freemaster to check SPI feedback signal from NVM and it is always 0xff.

Re: Using NVM chip on MPC5775B EVB

mariuslucianand — Tue, 22 Jun 2021 08:27:52 GMT

Hello @sonik82 ,

I had a look at your model and attached the model with a couple of changes. I don't have access to your board and I cannot test it, but I had a look at the signals using the logic analyzer. See the image attached below.

1. SPI settings - for that you can select the CS pin in the SPI_Config, you don't need to change it by hand. To select the device you can select the CS in the Master transmit block, the one you have already used.

2. In the Stateflow, you can remove the chip select state, because the DSPI will handle that, so you can only send and decode the responses from the SPI.

Hope this helps,

Marius

Re: Using NVM chip on MPC5775B EVB

Baris — Thu, 24 Jun 2021 14:55:24 GMT

Dear @mariuslucianand and @sonik82

I faced the same problem and I want to save any data in EEPROM, can you help with that?

Re: Using NVM chip on MPC5775B EVB

sonik82 — Thu, 24 Jun 2021 21:14:31 GMT

@mariuslucianand Thank you for model modification, but, unfortunately, I am still facing same issue SPI receive signal is always 0xFF and it does not matter which command I send to NVM.

Re: Using NVM chip on MPC5775B EVB

sonik82 — Thu, 24 Jun 2021 21:35:01 GMT

@mariuslucianand

As per datasheet, we need to keep Chip select low while sending command and getting data from chip

Your image shows that Chip Select goes High after transmitting of command, am I right?

Is it possible to keep this signal Low until we will get data?

Another question, these SPI settings are correct

to provide one of following SPI modes?

Also, to send 8 bits command and 24 bits address I need to change SPI frame size to 32, am I right? Then how to change this frame size dynamically? For example to Read Status Register it is required only 8 bits, to Read data 8 bits for command + 24 bits for address, to Write data 8 bits for command + 24 bits for address + Data.

Input and Output ports have same size, so does it mean that we can only send/get SPI frames with same size?

Re: Using NVM chip on MPC5775B EVB

sonik82 — Fri, 25 Jun 2021 07:04:23 GMT

I have changed SPI frame size from 8 to 16 bits, assuming that Chip select will be Low enough time to read feedback (8 bits) from NVM chip.

Now my SPI receive data is 0.

It looks fine for Read Status Register command, because bits 0,1,2,3,7 should not be set by default.

I am going to check Read/Write commands.

Re: Using NVM chip on MPC5775B EVB

sonik82 — Fri, 25 Jun 2021 07:50:06 GMT

I guess if I set SPI frame size to 24 bits then in case when my command is 8 bits, expected response also 8 bit, then I will get next 8 bits as 0xFF, am I right?

Re: Using NVM chip on MPC5775B EVB

sonik82 — Fri, 25 Jun 2021 07:51:42 GMT

@mariuslucianand

I guess if I set SPI frame size to 24 bits then in case when my command is 8 bits, expected response also 8 bit, then I will get next 8 bits as 0xFF, am I right?

Re: Using NVM chip on MPC5775B EVB

mariuslucianand — Fri, 25 Jun 2021 08:03:41 GMT

Hello @sonik82 ,

You can send variable bytes number (8, 16, 24, 32, 40 ...) with a continuous CS by selecting the Continuous transfer. But I've seen that you have already done that.

So, you select the frame size as 8, and you populate an array with the commands you want to send. F4irst byte is the command, then the next 3 bytes are the address. If you provide such an array to the SPI Send block, this will output on bus 4 continuous bytes, with only one chip select transition.

Hope this helps,

Marius

Re: Using NVM chip on MPC5775B EVB

sonik82 — Fri, 25 Jun 2021 08:52:49 GMT

@mariuslucianand SPI chip selection remains Low only when I am sending data to chip or it remains selected while receiving data from SPI also?

Re: Using NVM chip on MPC5775B EVB

mariuslucianand — Fri, 25 Jun 2021 09:02:05 GMT

Hello @sonik82 ,

I think it will remain low as long as you transmit. But, if you expect to receive for example 4 bytes from the NVM chip, you can compute the array like this: [cmd, addr, addr, add, 0xFF, 0xFF, 0xFF, 0xFF] basically you send an 0xFF or 0x00 as long as you want to receive from the NVM chip. Please give this a try.

Marius

Re: Using NVM chip on MPC5775B EVB

sonik82 — Sat, 26 Jun 2021 17:45:32 GMT

Hello @mariuslucianand

I have checked your idea. To do it, I have modified model by creation of 4 commands:

RDSR (Read Status Register) [ 00000101 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF]

WREN (Write Enable) [ 00000110 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF] because of

WRITE (Write to Memory Array) [ 00000010 0x00 0x00 0x00 11000100 0xFF]

READ (Read from Memory Array) [ 00000011 0x00 0x00 0x00 0xFF 0xFF]

When I use SPI frame size, received data is always 0xFF.

Same situation with SPI frame size 16, but with using size 24 output data becomes 0x00

Re: Using NVM chip on MPC5775B EVB

ranulf — Fri, 19 Nov 2021 15:28:12 GMT

@sonik82Sonic82, have you had any success yet in using the NVM chip on the MPC5775BEVB? I have tried also, with no success-so far.

Re: Using NVM chip on MPC5775B EVB

oguz — Thu, 30 Dec 2021 07:05:09 GMT

Hi,

I am dealing with the same problem but couldn't find the solution. Can you help me with that??