From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: MIME-Version: 1.0 Sender: glikely@secretlab.ca In-Reply-To: <4AD8CD30.6020003@theptrgroup.com> References: <4AD8CD30.6020003@theptrgroup.com> From: Grant Likely Date: Mon, 9 Nov 2009 12:23:05 -0700 Message-ID: Subject: Re: c67x00 with mpc85xx To: Jeff Angielski Content-Type: text/plain; charset=ISO-8859-1 Cc: Joel Lord , Linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, Oct 16, 2009 at 12:44 PM, Jeff Angielski wrote: > > We are using the Cypress USB Host (CY7C67300) with a Freescale MPC8544 and > can only get it to work if we add a delay after writing to the hardware > registers through the HPI. > > We tried playing with the SCY settings in the GPCM but nothing helps. It is > only when we add usecs of delay after our write() functions that the > hardware works. > > The datasheets make no mention of any write-then-read requirements and the > FAEs are stumped right now. > > I was just hoping somebody had some experiencing interfacing this chip to > the PowerPC and that they could offer some suggestions or ideas. I've worked with the part attached to the ppc440 inside a Xilinx FPGA. Though I ran into many problems, I haven't seen the problem that you describe. Sorry. g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd.