[ECOS] Flash Driver Read/Write Alignment Question

Jay Foster jay@systech.com
Fri Jun 9 17:10:00 GMT 2006


I am puzzling over how the eCos flash drivers are supposed to work when
using 16-bit wide flash devices.  I'm using an ARM architecture (ARM7TDMI,
ARM940T), and the AMD AM29LV160 flash device connected in the 16-bit wide
mode (CYGNUM_FLASH_WIDTH=16).

Looking at the flash driver code, this defines the flash_data_t as a 16-bit
type.  This results in all accesses to the flash device to be performed as
16-bit reads/writes.

The flash driver defines some special addresses (FLASH_Setup_Addr1,
FLASH_Setup_Addr2, etc.).  At least one of these will be defined as an odd
address.  This will result in an unaligned transfer, causing a DATA ABORT
exception.  What am I missing here?

Jay


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