How to erase memory of MC9S12XDP512 by using external pins?

[gunkuta]

Hello,

We are using MC9S12XDP512  MCU's and we want to erase everything inside of it. But we cannot put a software in it because it got stuck when we put wrong software into it. How can we boot the MCU and erase everything in it by using external pins? When we check the datasheet we saw a RESET pin but we are not sure if it boots the MCU and erase the ROM or just restarts the MCU. Is there a way to put MCU to its factory settings externally?

Kind regards.

[lama]

Hi,

I do not know which tool you are using but normally if the MCU is secured or we want to clean it then we have to connect suitable SW via BDM interface (USB multilink  www.pemicro.com) to the MCU. The pins MODB and MODA must be connected to GND and MODC is usually connected to Vdd via pull up. (The board should contain standard BDM connector for this purpose) The SW pulls the MODC down during reset using  interface circuit to be MODC=MODB=MODA=0 which enters the MCU in special single chip mode and we can enter mass erase command and unsecure command to the MCU.

You can download Unsecure_12 program from the www.pemicro.com which unsecures the MCU....or page

https://www.pemicro.com/support/download_processor.cfm?type=5

Moreover, if you are using CodeWarrior it always mass erase the MCU before a new code is loaded into it. Ther is also unsecure the MCU option in the menu. Sometimes i tis not working, noboddy knows why so it is better to use Unsecure_12 for this purpose.

Note; Normally the mass erase command is followed by writing security bits in the MCU to unsecure status to be MCU unsecured after next reset usually performed before application download. The application can then program these bits to required status.

There are threads solving this topic… for example..

https://community.nxp.com/t5/S12-MagniV-Microcontrollers/Erasing-a-secured-S12XD-device-via-BDM/m-p/...

Best regards,

Ladislav