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Altera_Forum's avatar
Altera_Forum
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8 years ago

Timing parameters of USB Blaster 1

I'd like to constrain the timing of the JTAG interface of my Arria 10 design for a USB Blaster Rev C (note: not USB Blaster II). However, the documentation doesn't mention any details about the timin...
Altera_Forum's avatar
Altera_Forum
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8 years ago

What are you hoping to achieve by constraining the JTAG interface? I assume you're referring to the TCK, TMS, TDI, TDO pins on the device...

The JTAG logic inside the device is fixed and not influenced by place and route. The JTAG timing is specified in the documentation, along with relative timing, which your JTAG host must adhere to. This is true regardless of USB-Blaster type of third party kit. Constraining the interface will not tell you whether the design meets the timing specified in the datasheet - it just will.

Unless you're talking about a JTAG interface into your logic, in which case you'd be using a user clock which you must constrain as normal.

Cheers,

Alex