Daniel Carrasco

Hi @malexander I do check that IC8 is damaged. I checked this on one of the two "bad" boards. The another board is not available now. It is impossible to see any damage at bare eye or even with magnifying glass. But using a microscope it is clear. I send atached one image. The chip is burned on its top-right corner. There is missing packaging and the ball grid can be seen. Then, this trouble seems to be a assemblying issue. I will contact with the mounting factory in order to clarify and watch the manufacturing procceses. Thank you, Best regards.

Hi @malexander R5 seems to be mounted. I tried to meassure it (4,67Kohm). I measure voltage at marked point (left pin of R5). It is 3.339Volt when the card is just powered on. When I connect using Vivado, it drops to 0,085Volt Best regards

Hi @malexander, I meassure that point referenced to GND. It shows 2.289V when HW manager is not connected. Then, if I connect USB cable and open digilent in HW manager, the voltage do not change at all. Best regards, D. Carrasco

Hi @malexander, @JColvin I have tried the propposed experiment. I soldered a 10K resistor between DIG_TRST and 3.3V. The result were the same. This signals start at 0V level when the card is swithed on. It also changes to 3.3V when I run Hardware Manager and connect to digilent Best regards, D. Carrasco

Hi, @JColvin Sure. I send you a schematic page which shows digilent connection. This module is connected directly to a buffer and a backplane conector. The buffer distributes several copies of TMS, TCK, T_RST signals, and protect FPGA circuitry. JTAG signals are routed to two FPGAs (Zynq and Virtex US+) and 3 mezzanine cards connectors, but it is done on the opposite side of the buffer There is not any pull-up between Digilent module and the buffer on any GPIO lines. Only GPIO2 is used (to perform TRST signal). When this signal reachs Zynq FPGA, there is a pull-up resistor. The other GPIO are unconnected (floating) Best regards, D. Carrasco

Hi @JColvin, I described 3 stages on a "bad" board behaviour: First, I poweron the card, with Digilent adapter USB unconnected from PC. GPIO2 shows low (38mV). Second. I connect Digilent USB to a PC. GPIO2 remains low (38mV). Third. I launch Vivado Hardware manager. Open Digilent adapter and start JTAG scanning. Then GPIO changes to high level (3.338V) Best regards, D. Carrasco

Hi @JColvin. I have tested all these on a "bad" board. Digilent module shows GPIO2 (PS_SRST_B) and GPIO1 at low level (about 30mV). But GPIO2 shows high level (3.3V). TDO,TDI, TMS, TCK and Vref pins are also at 3.3V level. Then, I connect digilent module JTAG to a PC. Nothing changes. But, when I started Vivado Hardware Manager, open Digilent and begin to scan the JTAG chain, then GPIO2 (PS_SRST_B) changes to low level. GPIO1 remains at low level, and GPIO2 stands on high level, too. I observed this behaviour on new cards. So this is the first poweron of a new digilent module. I don't think it could be a failure of a good module. I also compared R4 resistors of a "good" and "bad" Digilent module. Both meassure 99K5 Best regards, D. Carrasco

Hi @JColvin, I send an update. We have received one remaining JTAG-SMT2-NC component of the batch we used for card assembly. This is PB200-308 rev A So, if seems to be the first revision. I have done some research on the web. There are manuals for JTAG-SMT2 model from revision A thru D. How many revisions are for JTAG-SMT2-NC model? Could be a hardware issue in JTAG-SMT2-NC rev A? Best regards, D. Carrasco

Hi @JColvin I have meassure R4 resistor: 99K5. It is some weak pull-up, no? I am not sure I meassure the correct one. Silk layer are confusing. Could you send me a location component drawing? I send a photo marking the meassure. I suspect the issue could be a hardware version. It could be so? If so, I wanted to find a way to get HW version without component disoldering. It would be possible to check any data using USB connection (EEPROM values, or so on)? Best regard, D. Carrasco

Good afternoon. We have several JTAG_SMT2-NC modules on some identical cards. We have observed an anormal behaviour on GPIO2 pin. This pin are connected to PS_SRST_B pin of a Xilinx Zynq FPGA. In good cards, when the card are power on, GPIO2 signal goes to high (3,3V) level. So the Zynq is not reset. In some "bad" cards, GPIO2 signal goes to low level when the card are powered on. It could be a JTAG_SMT2-NC FW or version issue? Could I check JTAG_SMT2-NC version via current USB connection? If not, could I send you JTAG_SMT2-NC serial number or address in order to get FW version. Best regards, D. Carrasco