ICP Improvements

[Je Gold]

There are 2 application notes from NXP(Philips) which describes using the MCB900 with a simple transistor circuit and prog90x.hex bridge code. AN10258_1.pdf and AN10258_2.pdf.   AN10258_2.pdf seems to be the final and the MCB900 uses a NPN transistor to switch Vdd on the target being programmed.....

The NPN does not make a good Vdd switch...... and  the prog90x.hex code programs the Vdd switch (p2.3) as  quasi-bidirectional (weak hi-side drive)..... and  Vbe drop of ~0.6v

A classic load switch   NPN-PNP circuit overcomes the problems of weak drive from p2.3 and has less voltage drop across the switch.

See the Vdd switch circuit  attached.... note the resistor values may need to be adjusted to suit the transistors used.

Perhpas NXP (Philips) or some one else on this forum may consider a complete ICP application with improvements gained over the last year...  We know ICP is an issue for many first time users (just look how many forum members post questions on ICP).

Regards
Joe

[Je Gold]

In regards to my previous post above - I have had some time to do a spice simulation on the AN10258_2.pdf. MCB900 Bridge circuit .... and YES! the output does not look very poor (as I suspected).

I then spice modeled an other circuit using the "Classic PNP-NPN Load Switch" configuration... and I have assumed the MCB900 ports are configured to Quasi Bidirectional (as ver 1.6 of the bridge code prog90x.hex).

I table my findings and proposed ISP-ICP bridge circuit (improvement)  attached.

Regards
Joseph (joe).......

[Andy Ayre]

Thanks Joe! If you would like your work to be listed in the resources section of the site, please email me a Word document or PDF file that I can upload.

Andy

[rbtamd]

I believe it´s important also check the value of C10 in card MCB900. The right value is 10 uF, please check the link

http://www.keil.com/support/docs/2765.htm

Many MCB900 boards have 100 nF, and the power supply isn´t very stable. This is very important to enter in ICP mode.

Roberto Muñoz

[Rob Revens]

I table my findings and proposed ISP-ICP bridge circuit (improvement)  attached.

Hi Joe,

I've built and used your proposed circuit with success, but with one observation. Without the amended circuit connected, LED P2.3 lights to indicate ICP entry. With the cable connected it doesn't light at all. Has anyone else found this, or have I messed up building my cable?

Thanks,

Rob.

[Je Gold]

Sorry Rob,

I can't recall... Ive packed up my MCB900 at the moment.

PS... there's a better ICP note on the Resources Page of Flash Magic.

Joe

[Rob Revens]

Thanks for looking Joe. I'll check it again...

[pak]

Hi Joe,
        I am interested in ICP to program lpc devices. According to your comment

ICP
-----
ICP is very much more complicated in hardware.....  but does not need a stable core clock source and the PCK and PDA are synchronously clocked in side the LPC932A1 when programmed.

Do you have any comment or caution to build ICP?

Thanks,
pak

[Je Gold]

Hi Pak,

Please look at the resources page on the Flashtool web site (flashmagic)....  I have some documents listed there.

Also search the this forum for the key words  "ICP" you are bound to get lots of information.

Joe

[pak]

Hi Joe,
          Thanks for input, I have searched and read through about ICP. According to AN10258_2.pdf, I have to use lpc932 for ICP. Is it possible to use other lpc like lpc936? And have you tried MOSFET instead of using BJT?

Thanks,
pak

[Je Gold]

Hi Pak,

Yes, you can use LPC932a1, LPC935 and LPC936 as the "Bridge ICP Hardware" in the MCB900..... to program other LPC900 parts using ICP method.

I haven't tried  but, yes other people have used a P-channel Mosfet in place of the PNP transistor..... bare in mind some Mosfets do require substantial voltage to "swtich" on  - check the Vgs switch on spec's.

Joe

[pak]

Hi,
        If ICP can program most lpc9xx, is it possible to program ISP code to lpc chip? After that, the chip can be used in ISP mode. I have been tried on PIC chip from microchip, but not on lpc one. In PIC, I used bootloader and ICD2 (In Circuit Debugger). Bootloader is easily used to flash chip via rs 232. If any corruption of bootloader program, I use ICD2 to program bootloader on PIC and recover the bootloader again. Any idea?

Regards,
pak

[Je Gold]

Yes,

You can use  ICP to "reload" the ISP code back in to the LPC900 series micro's.

The ISP hex files are on the NXP web site somewhere...

Check this Adobe PDF doc http://www.nxp.com/acrobat_download/applicationnotes/AN10337_1.pdf


Joe

[LucasNorton]

There are 2 application notes from NXP(Philips) which describes using the MCB900 with a simple transistor circuit and prog90x.hex bridge code. AN10258_1.pdf and AN10258_2.pdf.   AN10258_2.pdf seems to be the final and the MCB900 uses a NPN transistor to switch Vdd on the target being programmed.....

The NPN does not make a good Vdd led light...... and  the prog90x.hex code programs the Vdd switch (p2.3) as  quasi-bidirectional (weak hi-side drive)..... and  Vbe drop of ~0.6v

A classic load switch   NPN-PNP circuit overcomes the problems of weak drive from p2.3 and has less voltage drop across the switch.

See the Vdd switch circuit  attached.... note the resistor values may need to be adjusted to suit the transistors used.

Perhpas NXP (Philips) or some one else on this forum may consider a complete ICP application with improvements gained over the last year...  We know ICP is an issue for many first time users (just look how many forum members post questions on ICP).

Regards
Joe

hello friend what are the latest ICP improvements? I am trying to get some detailed information so please help if you ca

[Andy Ayre]

I don't believe there have been any changes to ICP.

Andy