CY7C64225 supports flow control using CTS,RTS,DTR, DSR. You can enable the flow control option from the Application (like tera term). By default the flow control is enabled in the device. However your application can override the existing COM port settings like baud rate, parity, flow control etc.
I am working on a Linux platform and the driver I am modifying is cdc-acm.c
The spec on the chip says by default the chip has hw flow control disabled.
where do I find the programming document telling me how to confusing the device via the control registers?
The part you are using is a fixed function part. You cannot access its registers to configure it.
The only way you can turn on/off flow control is through CDC class commands (Set Line Coding).
You'd need to send this out through your driver by setting the appropriate fields and the device will configure its hardware accordingly.
1. According to http://www.cypress.com/?docID=48153, on page 4 of 20, it indicates that hardware flow control is available, but by default this feature is disabled. This document says 230kbps is supported, but next to the 230400, you see a * symbol. The explanation for this * symbol is shown under the RTS section where you will see a 'Note' that says at 230kbps, flow control is not supported.
2. According to http://www.cypress.com/?docID=38596, on page 5, it says 256kbps is supported, but not 230kbps. So we are not exactly sure which one is correct. Is 230kbps supported at all?
3. I checked the CDC spec and I dont see any CDC level command to control flow control. Can you help point me to the command to enable/disable HW flow control using CDC level commands?
4. So there is no low level registers in the device that we can control HW flow control?
To clarify, when I speak of HW flow control, I am referring to RTS and CTS signals. Is there a way to enable the device to control these signals by hardware?