usb to CFC chip

Un bel giorno Niels U. Kristiansen digitò:

SMSC

There are single chip USB to IDE converter in QFP 128. You can fit all the logics inside the CF socket. But if you are using USB (2 to 3 MB/s, there is no point in using CF (over 10MB/s).

While others have answered your question about such chips, I think the biggest problem you face is that your DS89C420 must implement an at least partial USB stack in order to talk to the chip you are looking for. This is by far WAY more complex than having your chip interface the CF directly and undoubtly will put much more load on it again compared to interfacing it directly. Interfacing a CF card on the hardware layer is pretty straight foreward and provided you have a reasonable datarate can be done with bitbangin on some gpio pins. Apart from this you would have to implement some sort of filesystem in both scenarios anyways. Now, if you want to simplify the interface or take of load from the DS89C420 why not use an aditional uC directly interfacing the CF card also handling the filesystem and define a simple (i.e. serial) protocol between the DS89C420 and said uC?

Just my 2¢ of course

Markus

I don't think that's what he's trying to do. It sounded like he wanted to use the DS89C420 to log data into the CF, and a USBCF chip to get the data back out when he plugs it into a PC. Problem is finding the chip, multiplexing, and making sure you create a file system the chip is willing to read.

Thanks. I misread it too. The ideal way is to use a USB capable Lexar CF. Unfortunately, they never publish the wirings and no other manufacturers follow this special feature.

Correct, thank you. Looks like there are many of those devices on the market:

Niels

At the risk of once again misunderstanding you, the CF's can operate on 5V and 3.3V and I asume that the datalogger (hence the DS89C420 ) will be idle / powered down if you use the USB chip. So IMHO you only have to make sure the DS89C420 is isolated from the CF pins at the point in time the USB chip is active - no?

Markus

This is all correct. And DS89C420 should not care much about 3.3V traffic if it is in idle or power down mode. Perhaps I will only have to isolate the power pins.

Niels