Author Topic: Simple cable schematics  (Read 3423 times)


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Simple cable schematics
« on: February 22, 2007, 12:49:28 pm »
How can I build a cable to flash the P89LPC921/922 with Flash Magic, the simplest method. (Just pretend I have the chip only, not development board). Any schematics? MAX232 and TXD RDX lines?
Thank you, but I am new on NXP microcontrollers.

Je Gold

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Re: Simple cable schematics
« Reply #1 on: February 23, 2007, 06:16:45 am »
If you are new to NXP LPC900 series micro's like the P89LPC921/922  then I strongly recommend you purchase a development kit first...  you can spend weeks, months playing around with the micro and not get anywhere.

One of the best value for money development kits is the Keil  MCB900... Information on the kit is available here  and can be purchase here  for $59 USD + freight.

Build your confidence with the MCB900 kit first.... then move on the the P89LPC921 / 922.

The 28pin P89LPC935 used in the MCB900 has the same functionalit as the P89LPC922 / 921 (except there additional features onthe 28pin part).

The plan would be to get familar with the MCB900 and the 28pin parts and then it is just a scale down to the 20pin P89LPC922 / 921 parts.

Both the P89LPC935 and  P89LPC922 / 921 program the same way....  just the pin locations are different.

To proggram the P89LPC922 / 921 (and p89LPC935)  you use the same labeled (same functional pins) Eg

 Ground (Vss)
 RXD  (connect to RS232 level converter)
 TXD  (connect to RS232 level converter)

The MCB900 programming circuit is here

All you need to do is transpose the pin numbers between the P89LPC935 and P89LPC922 / 921.

I have no affilication between Keil or LPCtools.