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Discussion - Software / FT2232H used in CPU-style FIFO mode - port setup ?
« on: April 26, 2021, 11:50:45 PM »
I am playing with a FT2232H on a Windows 10 Pro PC. I am using the latest version of TeraTerm to connect to the device. I have a C8051F340 connected to the device and am sending data to the device in the CPU-style FIFO mode.
I set the A0 & CS# lines low, then write 8 bit data to the device, strobing WR# after each byte. Once the string is fully sent, I return A0 & CS# hi. I'm currently not using any other pins.
I see data appear in TeraTerm fine when I send shorter strings, after a certain length the data transfer has troubles.
Eventually I wish to use this as a sort of high speed data logger to assist me in troubleshooting code that simply cant run with printfs to a com port. I'd likely be sending a few hundred to several thoughsand bytes, 1 to 3 bytes at a time, with a few micro-seconds in between.
I've been reading about USB, packet sizes & latency and am sure that's where my problem is. So, trying to understand all of this.
A few questions ...
1) Given my use case, am I using the most appropriate mode ?
2) In changing the port settings for the VCP in Windows 10 Device manager - Port settings - Advanced settings, do I really need to reboot for settiing to take effect ?
3) Is it true that the baud rate setting here is ignored ?
4) What exactly do the "Minimum Read/Write Timeout (msec)" settings control ?
I set the A0 & CS# lines low, then write 8 bit data to the device, strobing WR# after each byte. Once the string is fully sent, I return A0 & CS# hi. I'm currently not using any other pins.
I see data appear in TeraTerm fine when I send shorter strings, after a certain length the data transfer has troubles.
Eventually I wish to use this as a sort of high speed data logger to assist me in troubleshooting code that simply cant run with printfs to a com port. I'd likely be sending a few hundred to several thoughsand bytes, 1 to 3 bytes at a time, with a few micro-seconds in between.
I've been reading about USB, packet sizes & latency and am sure that's where my problem is. So, trying to understand all of this.
A few questions ...
1) Given my use case, am I using the most appropriate mode ?
2) In changing the port settings for the VCP in Windows 10 Device manager - Port settings - Advanced settings, do I really need to reboot for settiing to take effect ?
3) Is it true that the baud rate setting here is ignored ?
4) What exactly do the "Minimum Read/Write Timeout (msec)" settings control ?