On Wed, 2007-02-07 at 09:58 +0100, Attila Kinali wrote: > The only referneces i found there was either to Wiggler type > cables (using the parallel port) or to BDI2000 (which is a > full fledged debugger and costs >2000EUR).
It should be possible to build a parallel port <-> JTAG converter using a PIC or an 8051 and not much else. Should be a lot faster than the "wiggler"/bit banger type. The limit would then be how fast the microcontroller could accept a byte and output it serially and not how fast the data could be transferred out of the printer port and across the printer cable. (Ok, a strict traditional 8051 won't be all that fast: a 12 MHz clock translates to 1µs for the fastest instructions. Special code for each byte value means that the fastest code sequence can be used for each. As far as I can see that's two or three 1µs instructions per bit, depending on whether the data transitions or not. There's a maximum of four data transitions per byte so that's 4+16=20 instructions of 1µs each. So 20µs per byte is 50kB/s, ignoring all overhead. Not particularly fast after all. Happily, there are plenty of modern 8051s that can either use a faster clock or use fewer clock periods per cycle!) -Peter _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
