Jon- The Silicon Labs chip is not a typical 8051. You are correct about a standard 8051, but this chip is more of an 8051 core running at 50 or 100 MHz. They may have a version with an Ethernet MAC and DMA as well.
Which ARM7 are you looking at? Atmel has some good ones, and I know some people who are using Freescale for embedded ethernet products. There are a lot of good ARM7 processors out there. Javid ----- Original Message ----- From: "Jon Elson" <[EMAIL PROTECTED]> To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> Sent: Saturday, October 27, 2007 5:15 PM Subject: Re: [Emc-users] Ethernet I/O > Brian Michalk wrote: >> I've done a bit of programming and circuit board design with Silicon >> Laboratories 8051 chips. They have an ethernet developers kit complete >> with schematics. >> http://www.silabs.com/tgwWebApp/public/web_content/products/Microcontrollers/en/EthernetDK.htm >> >> >> I have not priced the components, but a board should cost less than $20 >> each. > The 8051 is not a good choice for real time control of motors at > high precision. I suspect that an 8051-based interface might > just barely be able to keep up with a 1 KHz servo update rate > (2000 packets/second received, 1000 packets/sec sent back to > PC). I'm hoping to be able to turn up the servo update rate > quite a bit with this system. The chip that I've been looking > at has a 10/100 Mbit/sec ethernet MAC on chip, with DMA transfer > to dedicated on-chip RAM. It is based on the 32-bit ARM7 > processor, which is likely to be hundreds of times faster at > handling the ethernet protocol. Even at 1 KHz servo rate, it > would have to receive a request from the PC, decode it, perform > the requested register reading and then build a packet to send > back to the PC. The PC would take 50 us or so as do the PID > calculations and then send a velocity command packet to the > device. It would be good to handle each request in maybe 100 us > or so. I have great doubts that an 8051 could process the > protocol stack and do the I/O in 25 or so instructions. > > Jon > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
