I dumped the flash memory of an old ARM9 Chip running VxWorks using the SEGGER J-Link and the
savebin command from J-Link Commander.
Here is an example of a line of HTML stored on memory.
<!DOC^YPE H^MN PUNLOC "///W?C//NTN NTOL 4.01//EN" "nt~p>//ww.w?.oro/^R/h~mn4/s~roc~.ntn">
What it should be
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
The pattern of error that I see is the last 4 bits of every other byte is replaced with different bits.
So the two bytes CT(43 54) in DOCTYPE become C^ (43 5E). The first 2 bits of the two bytes are always correct but the last 4 are not.
My question is, what is causing this systematic error? Is it a problem with the JTAG configuration or some ECC or something thing else completely?