Posted on May 17, 2011 at 11:56 Hello all:
I'm the customer Manz referred to. Since his original post, I have followed this problem up. Here's what I have found:
1. The uPSD part correctly programs and verifies most of the time.
2. If I ''Verify All'', the verify fails either in the flash or the PSD approximately 10% of the time. When it fails, it reports a single bit error at a particular location, e.g. ''expect 0xB1, read 0xB3'', although the errors reported are not repeatable.
3. If I ''Program/Verify All'', the operation fails perhaps approximately 10% of the time. Running ''Verify All'' immediately after such a failure shows that the part is indeed correctly programmed, i.e. the failure is in the verification step.
4. Infrequently, running ''Program/Verify All'' results in the problem described in the original post: the flash fails to program at all. This has happened three times in approximately 200 programming attempts. Replacing the part fixes the problem
.
5. I am using 4-wire JTAG programming. Circuitry is as per DK3200 schematics, but with no series 100ohm resistors in TCK and TMS lines. The JTAG signals are all well defined with clean edges and fast rise times. The minimum TCK period is approximately 2us. My FlashLINK programmer is a Rev F PCB. Target is running at 3.3V.
Does anyone have any insight into this problem? Any help would be greatly appreciated.
Andrew Ward
