I'm using the USB-JTAG HS3 dongle as JTAG interface to our proprietary systems.
I implemented JTAG transactions for reading and writing registers on top of the HS3 Adept API.
This works fine but I noticed that there is always a time gap between transactions I can not reduce.
More precisely, I can reduce it using large blocks in batch mode but this is not suitable for many individual register read/write ops.
In fact, the actual data speed looks more than 10x slower than the JTAG frequency. At 15 MHz JTAG I can only perform about 7000 transactions (each one takes about 100 TCK clock cycles).
I can not believe it is just SW overhead. Is there any reason for that? Is there a way to reduce the gaps?
HS3 JTAG slowness
in Other
Posted
I'm using the USB-JTAG HS3 dongle as JTAG interface to our proprietary systems.
I implemented JTAG transactions for reading and writing registers on top of the HS3 Adept API.
This works fine but I noticed that there is always a time gap between transactions I can not reduce.
More precisely, I can reduce it using large blocks in batch mode but this is not suitable for many individual register read/write ops.
In fact, the actual data speed looks more than 10x slower than the JTAG frequency. At 15 MHz JTAG I can only perform about 7000 transactions (each one takes about 100 TCK clock cycles).
I can not believe it is just SW overhead. Is there any reason for that? Is there a way to reduce the gaps?