2009-09-24 06:10:02 Force NET2272 into full-speed mode
Mattias K (SWEDEN)
Is there anybody who has tried to force the usb chip (NET2272) into full-spedd mode?
We have tried setting the testbit as described in the manual without success.
From the manual:
5.9 USB Test Modes
The Force Full Speed and Force High Speed bits of the XCVRDIAG register can be used to force the NET2272
into full and high speed modes, respectively. These forcing bits must not be used in normal operation; they are
for testing purposed only. In normal operation, the NET2272 automatically performs USB 2.0 Chirp Protocol
negotiation with the host to determine the correct operating speed.
USB 2.0 Test Mode support is provided via the Test Mode Select field of the USBTEST register. These bits select
the appropriate USB Test Mode settings (see section 9.4.9 in the USB Specification Revision 2.0 for more details).
Normally, the host sends a SET_FEATURE request with the Test Selector in the upper byte of wIndex. The Test
Selector can be copied directly into the NET2272 USBTEST register to select the correct test mode.