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tomcircuit / MAX7000S-CPLD-JTAG-Tester

EPM7064SLx84 CPLD Tester
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Enhancment #1

Open maded2 opened 3 years ago

maded2 commented 3 years ago

hi Tom, I know your design is just a tester board. But Sparkfun used to sell a clone of the ByteBlasterMV programmer (http://www.sparkfun.com/datasheets/DevTools/FPGA/Altera%20Programmer/Altera_Programmer-v10_Schematic.pdf). Which maybe good to add to your board so that it can be use to unlock the EPM7128S. I am currently researching how to do that as I've several used EPM7128SLC (PLCC84) which JTAG cannot scan from Aliexpress.

Also do you know where the nSTATUS pin is on the EPM7128S?

thanks, eddie

tomcircuit commented 3 years ago

Hi Eddie, My tester board is designed to work with either a USB Blaster or ByteBlaster (real or clone) - or, really, I suppose any USB-to-JTAG adapter that you might have on hand. The ByteBlaster was the precursor to the USB Blaster. The ByteBlaster connects to a Parallel (DB25 LPT port) and relied upon some software driver to do all of the JTAG bit twiddling. I no longer have any computers with LPT ports (what a relief!) Unfortunately, neither the ByteBlaster nor the USBBlaster can unlock a MAX7000S device with disabled JTAG pins.

There is no nSTATUS pin on the MAX7000S family of devices - TDI/TDO/TCLK/TMS are all that are present.

Sorry to disappoint you! Tom