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AdamLevine's avatar
AdamLevine
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6 months ago

USB Blaster II

We are using MAXV and Quartus Prime Lite Edition. We purchased a USB-Blaser II. We are able to program the device, however in between "sessions" when we plug in the USB it sometimes fails to recogn...
Hdl
lixy's avatar
lixy
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6 months ago

Hi Adam,

​

I think this looks like the connection is not stable.

1- Please still try other machines and USB blaster II cables. Make sure the cables are working.

2- From the schematic, The JTAG header pin order looks fine. But I can not see whether there's pull-up or pull-down resistors. Please check from the schematic for the JTAG pins and confirm:

-- Connect TCK pin to a 1-kΩ pull-down resistor to GND.

-- Connect TMS pin to a 10-kΩ pull-up resistor to VCCIO1.

-- Connect TDI pin to a 10-kΩ pull-up resistor to VCCIO1.

If these pull-up/pull-down are not correctly connected, then the JTAG state machine in MAX V might fall into in a wrong state.

3- Also, sometimes this also happens if the JTAG header has some soldering issues or the cable are not well connected. Although the possibility is low that this happens to two boards.


Best Regards,

Xiaoyan