Snail Instruments wrote:

> Hi Kevin,
>
> it all depends on the data rate you need to exchange. The USB controller
> will take care of the hi-speed USB communication and you can read/supply the
> data with the more convenient and less timing critical I2C protocol. So if
> you are after few bytes, then perhaps the 12C508 running at 32kHz will keep
> up (would have to check the 32kHz clock, but at 4MHz for almost sure).
>
> There is also the National USBN9206 with SPI (and parallel interface), which
> I mentioned a week ago, but with very little response, maybe due to friday
> afternoon mailing. BTW, how are you going to solve the PC side of the link ?

My initial application is to connect to a peripheral at 9600 baud over a
proprietary RS485 link. The original device uses a 16F84 to interface
between an RS232 tranciever and an RS485 tranciever.

The reason for the question is that I have been trying to decipher the
USB protocol and have not had a lot of luck yet. I have not begun to
work on the PC side of the link yet.

The USBN9602 is an interesting part. For my purposes the PDIUSBD11
may be  better because it is smaller. I will have to do some research.

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| Dr. Kevin Dale Kirmse, PhD EE
| Portable System Design, High Speed Serial Links
| FPGA Design, Video Hardware, Graphics Hardware
|
| King of Prussia, PA 19406
| kirmse@netaxs.com
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