host controller neglects sending 'ISO IN' request | Cypress Semiconductor
host controller neglects sending 'ISO IN' request
I'm testing transfer performance with FX3 DVK (Rev2).
in BULK IN transfer, max packet size = 1024, burst length up to 16,
everythig seems OK.
the transfer rate is around 120MB/s. (moderate...)
but in ISO IN transfer, max packet size = 1024, burst length = 16,
the host controller sometimes neglects sending 'IN' request approximately 3ms.
I mean no "ACK TP" (it's necessary to start ISO IN transfer) appears on the USB bus during that time.
I think this problem is a matter of host chip or driver.
Have anyone experienced this kind of problem?
and, how did you solve it?
- application requests 131072 (=1024*16*8) bytes data by calling BeginDataXfer.
- USB 3.0 I/F card is connected to PCIex1 gen2 port.
- the host chip is Renesas D720200. Driver version is 22.214.171.124.
- Cypress driver (cyusb.sys) version is 1.00.0000.001