Can't erase 9S12C32 flash

usdkurt — Tue, 02 May 2006 02:13:04 GMT

Hi,

I've got a handful of prototypes that I'm having trouble with (well, actually, all of my prototypes, not just a handful out of a larger group). The major problem is this: at a seemingly random point in the cycles of assemble-program-debug I will lose the ability to erase the flash and program new code into a device. I use the P&E Micro PKG12Z set of tools; our project is written in assembly, and I'm using the P&E USB Multilink to connect to the BDM port. The error shows up when I do a blank check after an erase within PROG12Z: the erase does not report an error, but the blank check does. Once a device reports this failure to erase, I can't do any further erasure or programming.

Some random facts about the situation in the hopes that this will stimulate someone's memory:
-- We're using a 4 MHz crystal, and once our application code gets going it multiplies this up to 24 MHz (in a 25 MHz part), using SYNR=5 and REFDV=0.
-- I've set FCLKDIV to 19, which I believe causes the flash oscillator to run at 4000000/(19+1)=200 kHz.
-- We initialize location FF0D to 02 in the download image, which should mean that FPROT comes up with FF (unprotected). Later, after we examine a jumper to determine if a firmware update is requested, we write once to FPROT with the value $DA, which should protect the lower 2k and upper 16k of our flash image.
-- Location FF0F has 02 in the download image, which should initialize FSEC to unsecured state.
-- Running P&E's Usecure 12 tells me that FSEC=02 at the start, it does something, then FSEC=02 at the end, try talking to it. I can talk to it afterwards, but erasing still fails as described above.
-- The prototypes may have been run with FCLKDIV set to 18 for a while, but I don't think that flash was erased or programmed from within the firmware on more than one or two of the four.

Thanks for any help or suggestions you may have.

Kurt

Re: Can't erase 9S12C32 flash

Nabla69 — Tue, 02 May 2006 04:58:56 GMT

Hello Kurt,

It's possible your MCU has been accenditally secured during your manipulations.

You can have a look at the message Re: Escape from Security Mode in 9S12DG256 where an Unsecure command file is available.

Alvin.

topic Can't erase 9S12C32 flash in S12 / MagniV Microcontrollers

Can't erase 9S12C32 flash

Re: Can't erase 9S12C32 flash