MAX IIZ JTAG Programming - MAX IIZ JTAG Programming Hello, I am new to FPGA / CPLD and im having some problems with my project. I am trying to program a CPLD (EPM240ZM68C7) using a USB Blaster and Quartus Prime. Ive been having problems with messages such as "Warning: Uncertain JTAG Chain. Detected 0 devices" and sometime "Error: No device detected". My questions are: 1) This version of CPLD my VCCINT is supplied by 1.8V and VCCIO (Bank 1 and 2) with 3.3V. The pin 4 on the JTAG connector, should be attached to the 1.8V or 3.3V? 2) Some datasheets say that the TMS should have a 10k pull-up resistor and TCK should have a pull-down resistor of 10k and some 1k. Which one is correct for TCK, 10k or 1k? Thanks Replies: Re: MAX IIZ JTAG Programming Hi, I am glad that you figure out the issue. Replies: Re: MAX IIZ JTAG Programming Thank you so much for the answers. I am having problems to program my CPLD but i believe it is a bad soldering (uBGA) since when i check the signals on the oscilloscope, my TCK is fine, my TDI is fine but my TDO is always at low. I have only one device on the JTAG Chain, so it could only be this specific device. Replies: Re: MAX IIZ JTAG Programming Hi, 1) This version of CPLD my VCCINT is supplied by 1.8V and VCCIO (Bank 1 and 2) with 3.3V. The pin 4 on the JTAG connector, should be attached to the 1.8V or 3.3V? The pin 4 should be attach to 3.3V as the input and output buffer is provided by VCCIO pin. 2) Some datasheets say that the TMS should have a 10k pull-up resistor and TCK should have a pull-down resistor of 10k and some 1k. Which one is correct for TCK, 10k or 1k? It should be 10K pull-up on TMS and 1K pull-down for TCK. Please refer to https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/max2/max2_mii51013.pdf - Figure 11–1