Occasional Contributor
Frequent ContributorWithout seeing your schematic and PCB layout it is hard to make any significant comments. That being said:
What does your input clock signal look like? Is it monotonic with no noise?
Can you zoom in on a transition on the data? Interesting to see what an output transition looks like in detail.
What does the power rail look like, wrt noise?
I have multiple EPM7064S and EPM3064A parts on boards (using PLCC packaging) and don't see such issues.
Occasional ContributorYou can find the schematic and the layout in the attachment.
In the layout I planned to use a socket for the EPM3064 chip. I found a small one in the internet, but it does not meet the specified dimensions of a TQFP44 chip. With the socket the chip cannot be programmed at all.
Therefore I made a second version with the chip soldered directly on the board. For the tests I only mounted the chip, the JTAG socket, the 4 blocking capacitors and some pins for power supply and input/outputs.
The layout is shown in a version with highlighted ground and VCC.
