I´m using a N25Q128..3E to store a bitstream configuration for an FPGA.
To program the flash I´m using an ftdi2232H chip.
I have two ways how to program the flash (with the same ftdi chip!): Via the JTAG and the
FPGA (which first loads a JTAG to SPI converter core to do so) or directly via SPI.
I prefer the last way as it is with less possible error points and I suppose that it
should be faster.
Programming the flash directly via SPI is much slower than the indirect way through JTAG
and the FPGA.
I think that it does not has to do with the SPI clock frequency as it is even slower in
But I can observe a significant difference in the Idle time between two SPI
You can see that at attached screenshots. The idle time (red arrows) is 2 - 4 times longer
in direct case (below) than in the indirect (above) (as there are about 16000 SPI
sequences it really does matter).
1. I couldn't find any flashrom parameters to change idle time. Is there any?
2. When looking at the source code I found the function call
'ftdi_set_latency_timer' but can´t find the function definition. Does it has to do
with the idle time?
3. Which function should I touch to change idle time if there is any to do so?
4. Any other advice about how to change the idle time?
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