Re: MM9Z1J638 erase EEPROM problem

romanarxxy — Mon, 27 Jan 2025 10:39:42 GMT

I've found adres of registers in demo software for codewarrior, checked it and now all i need is a guide how to erase/program in right way because i think i missed something

I'm setting up FCLKDIV=0x01 for 250kHz it returns me 0x81 so its ok

then i'm checking FSTAT=0x80

then i'm sending command with 2 words 0x1210 ->0x0000

and then nothing happens, what have i done wrong? I also tried to write something in register FSTAT but if i'm doing it it returns me FSTAT=A0 means ACCERR... really need help with it

Re: MM9Z1J638 erase EEPROM problem

lama — Mon, 27 Jan 2025 15:14:40 GMT

Hi,

Please compare this project with yours,

https://community.nxp.com/t5/S12-MagniV-Microcontrollers/S12Z-Flash-example-code/ta-p/1108954

If there is no oscillator on the board the the MCU uses internal oscillator and BUSCLK is set by PLL.

FDIV is based on the busclk so it is necessary to know it.
6.14.3.2.1Flash clock divider register (FCLKDIV)

Never, show E/W data in the memory window because it reads FLASH during E/W by MCU which causes error. The flash is not allowed to be read while E/W. So, check written data by code or show another address space in the memory window and then, after E/W, you can shift it and check whether there is a correct change.

Best regards,

Ladislav

Re: MM9Z1J638 erase EEPROM problem

romanarxxy — Tue, 28 Jan 2025 00:04:36 GMT

Okay, i figured out everything, Now i can erase, read, write eeprom, now i have different kind of problem "speed" can i somehow use more words in a single comand to write? as i can see in datasheet there are option to send 4 words at a timem but also in datasheet we see that FCCOBIX can change only 0-2 so i cant send more than 1 words in single command, how i can deal with it? or any other ways to speed up proccess, now it takes about 30 seconds and its quite a lot (30 seconds to erase+write+verify(read))

Re: MM9Z1J638 erase EEPROM problem

lama — Tue, 28 Jan 2025 11:30:25 GMT

1) There are two ways how to program MCU with self made programmer – either via BDM or using bootloader. Of course, bootloader also requires its load via BDM.

If you use mass erase command then it is suitable immediately unsecure the mcu by rewriting the security byte in the flash. If it is not done then the MCU is secured after next reset.

You can also erase the flash sector by sector.

Bootloader is described here:

https://community.nxp.com/t5/S12-MagniV-Microcontrollers/S12Z-MagniV-Serial-Bootloader-Interface/m-p/1522147

https://community.nxp.com/t5/S12-MagniV-Microcontrollers/Simple-Serial-Bootloader-for-S12Z-AN-draft/ta-p/1126452

First of all you should read the data sheet to understand how the programming and erasing memory works.

2) If you mean you want to program the data into the EEPROM and FLASH by means your application SW, then it is another story.

In both cases it is necessary to switch off the memory window (or shift to the part which is not EW) because it reads flash and it is not allowed to read the flash while it is E/W.

My question is. Does the “self made programmer” means bootloader or debug interface or your application SW?

To find register values, the best way is to look into a header file.

I understand your code as a programming algorithm and commands you are sending via BDM to the MCU. Am I right?

So, once more. I ask for confirmation. You communicate with the MCU via your own BDM interface using BDM commands.

Am I right? If yes then it is relatively easy to port SW algorithm for E/W to BDM command flow. Of course this step by step programming algorithm is not fast but it is suitable for first approach to understand procedures.

You have been asking about addresses of register. => The data sheet.

One good note. After reset the MCU works on defined busclk with internal oscillator until you change it. If you want to use this clock then you do not have to touch PLL oscillator setup.

So, for example… prepared in one breath without checking…..There BDM COMMANDS are in the data sheet … it is just simply rewrites SW procedure to BDM procedure.

//MASSERASE FLASH

Send_cmd(ERASE_FLASH); // BDM_cmd=0x95

Wait(16); // d=delay 16 target BDCSI clock cycles (DLY)

//UNSECURE DEVICE AFTER MASS ERASE - WRITE SECURITY SECTOR

//WRITE_MEM.sz Non-intrusive Yes (0x10+4 x sz)/ad24/wd.sz/dack Write the appropriately-sized (sz) memory value to the location specified by the 24-bit address

Write_Mem(soByte, FSTAT, 0x30) // clear ACCERR and PVIOL: soByte= 0x10, FSTAT (0x386) = 0x380+0x0006, BDM_cmd=0x30