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i want to use jtag just because i read out the jtag id by openocd very easy. and openocd support some X-device directly,so i thought maybe A-device can be support by openocd too...
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You're fighting several battles here; the USB-Blaster protocol is not officially published, but it has been reverse-engineered, and that allows OpenOCD to use the USB-Blaster as a JTAG probe.
The JTAG protocol defines some standard instructions, of which the IDCODE is a standard instruction, so OpenOCD can read the FPGA ID code. Unfortunately the instructions associated with programming a device via JTAG are not published, so it is not possible for OpenOCD to support device programming.
Altera have added an FPGA manager to their new SoC devices. That FPGA manager allows you to "take over" the FPGA JTAG and program the device. I have not investigated the software associated with that feature, but you may find that it exposes the programming instructions (at least those used on the newer generation devices).
Cheers,
Dave
Honored Contributor
