Peter Truong

Memory overlapping on 5282

Discussion created by Peter Truong on Jul 31, 2008
Latest reply on Aug 15, 2008 by Peter Truong
I'm just wondering if anyone has any info regarding the handling of memory overlapping between internal FLASH and SDRAM on the 5282. So far I have found that the 5282 on my target board (ie. Netburner 5282 module) gives the access priority to the internal FLASH over the SDRAM and this does not cause any execution problem. However, I'm not sure if this is valid/legal to have memory overlapping like this and have a little bit concern that this may cause some conflicts in the future.
In the 5282 manual, I can only find info regarding memory overlapping restriction for DACR and CSAR and the access priority among IPSBAR, RAMBAR, Cache, SDRAM, and chip selects.
The reason that I consider overlapping the FLASH and SDRAM is because:
1) Prefer the FLASH containing the boot code to be mapped to 0x0000 0000 and no subsequent relocation (eg. move to 0xFFC0 0000 during boot code execution).
2) The SDRAM is an 8MB module and prefer to have it cover the region at 0x0020 0000 onward.