topic Re: Code not getting downloaded correctly on MC9S12DB128 in S12 / MagniV Microcontrollers

Code not getting downloaded correctly on MC9S12DB128

pammu — Wed, 01 Feb 2006 03:05:14 GMT

I am using MC9S12DB128 controller. In my linker file, I have given the following memory settings:

Start Address Size

EEPROM 0x800 7ff

RAM 0x2000 1fff

Stack 0x2ffe

On downloading the code on my target using the Cosmic ZAP ICD through BDM, I get "IRAM Invalid Address - Can't program Flash" error.

The same code downloads and works fine when I have the following memory settings:

Start Address Size

EEPROM 0x800 7ff

RAM 0x1000 1fff

Stack 0x1ffe

Can anyone tell me whats the problem? In the ZAP ICD, I choose the targer as DB128.

I dont face this problem on the DP256 evaluation board. DP256 has 12kb RAM and DB128 has 8kb RAM.

Re: Code not getting downloaded correctly on MC9S12DB128

Steve — Wed, 01 Feb 2006 23:16:06 GMT

I don't fully understand the problem pammu but I suspect it arises due to the reset position of the RAM. Check the databook, but in general the RAM block is aligned at 0x0000 at reset so an 8k RAM part has RAM from 0x0000 - 0x1FFF (12k is 0x1000 to 0x3FFF because it is in a 16k block which is top-aligned at reset).

So unless you move the RAM it will not exist above 0x2000 and will cause an error if you attempt to access it.

Have you tried asking Cosmic about this?

Re: Code not getting downloaded correctly on MC9S12DB128

pammu — Thu, 02 Feb 2006 01:11:01 GMT

Steve,

What you say is correct. On reset the RAM is aligned to 0000. So in my code I am remapping EEPROM and RAM to begin at 800 and 2000 respectively. But this is not working. I am just unable to download the code. But if I remap the RAM to 1000, everything works fine.

I am in contact with Cosmic regarding this. Lets see what they reply.

Message Edited by pammu on 02-01-2006 11:11 AM

Message Edited by pammu on 02-01-2006 11:12 AM