Programming the 89LPC935

[iand]

Hello,
I am new to those devices and I have simple question.
I have a 89LPC935 in my hands and i would like to program it for a simple use. Is it possible to program such a device directly from the serial port? I had lots of trys by connecting a MAX232 between the microcontroller and PC serial port without any success results.
Can anyone help me to find my way pls. Thanx you in advance, Iand

[Andy Ayre]

Yes, it should work. Connect the UART of the device to a PC COM port via a MAX232 or similar. Best to use a real COM port rather than a USB cable.

A simple debugging test is to use Hyperterminal (8 bits, no parity, 1 stop bit, no flow control) and send single characters. Use a scope to check they are arriving at the receive pin of the LPC935.

Andy

[erikm]

Yes, it should work. Connect the UART of the device to a PC COM port via a MAX232 or similar. Best to use a real COM port rather than a USB cable.

Best?
many cases of non-working download when using a USB cable have been reported.\
The sad case is that many USB cables a "only what is needed"

Erik

[iand]

thanks for the reply guys,
just to ask you if there is any schematic for a simple operation with the LPC935 it would be confirm that my circuit is correct.
i had spend so mutch time without any results so far and i am a bit disappointed with my circuit.
Thanks, Iand

[Je Gold]

The safest and quickest way is to purchase a Keil MCB900 development kit....   It's ready to go!

See the kit here
http://www.keil.com/mcb900/

See the schematic here
http://www.keil.com/mcb900/mcb900-schematics.pdf

Purchase from here (and other places)
www.lpctools.com

Because you are a beginner... then I strongly suggest you purchase the MCB900 kit......  Otherwise you will spend weeks/months  trying to get the P89LPC935 in to programming mode so it can be programmed by Flashmagic.

Once you get familiar with the MCB900 kit and how to program the P89LPC935.... then move on to the hardware (study the MCB900 schematic,  Study the Flashmagic manual).

TRICK for putting the P89LPC935 in to programming mode  -------  immediately (within 50uS) after the P89LPC935 is powered up... 3 x 50uS logic pulses  must be given to the RESET pin of P89LPC935........ The MCB900 has a circuit to do this!

Hence study the MCB900 1st !

Only then if you have trouble come back to this forum.....

Joe