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Hello Dan,
as you already found out, only the CFM part is responsible for the logic configuration. Although the UFM part is programmed by default, it would be only needed if you are using the user flash in your design
and want to initialize it during device programming. In some designs, it may be in contrast desirable to exclude UFM from an logic update, e. g. cause it contains calibration data or device personalisation.
I never experienced similar problems with MAX II user flash. I wonder if you have some logic that is unintentionally rewriting the flash and thus exceeds the possible number of reprogram cycles after a short time or if the flash content may be self-modfied between program and verify?
Anyway a read-back of UFM and compare with original content may help to understand the issue.
The JTAG and power-up point in the handbook should be always satisfied when using a TCK pull-down and a TMS pull-up. Actually, MAX II has already built-in weak resistors, but they may be overdriven by an external circuit sometimes, so it's better to use the suggested external resistors.
I understand from your post, that the power supply shouldn't be a problem. To be sure, I would perform the test for VCCINT during device programming, that's described in the handbook.
Regards,
Frank
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Hi again,
I am able to erase the IC. I would assume it erases both the CFM and UFM. Following an erase, I can not program the device if I try to include the UFM section. I can reprogram if I exclude the UFM. Such is the case even if I try to load a design (pof file) that does not utilize the UFM section.
I wonder if I can conclude that the JTAG is working properly. I am suspecting that there is something going on with the memory power and ground, but why should that be different then the CFM section? I will try and find the supply and ground pins dedicated to the UFM, but I realy do not think that is the issue. I will try and look up what you sugested regading the VCCINT testing.
So I assume the problem is not with the JTAG. I am using the memory flash via the megafunction, and it is set to parallel memory, only 3 words at 16 bits each. I do have a mif file to initialize some data. I used parallel memory before (1 word of 16 bits), but without initalizing data and that workes fine on exsiting product hardware.
The issue here is that once the IC fails to verify the UFM, the problem presists even when I erase the IC (no error messages on erase). Loading a file without UFM does not clear the problem.
That is a real puzzle. I wonder if I damage the IC's when trying to program thye UFM. It is possible that I am doing something dumb, that I am not suposed to do. There is so much to learn and read, it is overwhelming...
Regrads
Dan
Honored Contributor
