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Altera_Forum
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16 years ago

Error in JTAG chain before reprogramming

I'm trying to reprogram a MAX II CPLD with USB Blaster in JTAG mode. When I click Auto Detect appears error message “Unable to scan device chain. Can’t scan JTAG chain.” Testing JTAG chain with...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

Signals TCK, TDI, TDO, TMS aren’t generated by USB-Blaster?

Why, if JTAG signals are correctly connected to the corresponding reserved pins of Altera's chip, programming doesn’t start independently of other external connections? Physically the chip consists of enabled or disabled logic ports. Isn’t CPLD structure an array of logic elements?

If board’s supply is as requested, what forbid programmer to have access to JTAG chain?

How can I verify correct working of download cable?

Thank you very much.