LPC932 appnote

[erik malund]

I feel that the support in the appnote is somewhat lacking.  I have no intention of producing 1000s of units using the Keil board instead of a dedicated board.
1) there is no value for R14, what is it?
2) when not using the Keil board (ISP on p-roduction board) is the Vdd control required?
3) Keil does a lot of fancy tapdancing with the reset and !EN, that must be possible to simplify if some requiremets are applied (e.g. have the cable plugged in before powering up the LPC932)

Erik

[Andy Ayre]

Erik,

1. I looked on the hardware and R14 is 47k. It's now fixed in the appnote. Thanks for pointing this out.

2. If you wish to use the hardware entry method, then yes, VDD control is required. If you look at the timing diagram for the hardware entry method, you will see that three pulses need to be applied to RST a certain time after powering up the device. So Flash magic needs to be able to power down the up the device to start the sequence.

3. Most of the hardware is used to generate the three pulses. Because the timing requirements for the maximum pulse widths is relatively short, it is not possible to generate the pulses from Windows applications (might be possible if you write a device driver for each version of Windows...). So, the method used is to output FFH, FFH, FFH back to back out of the COM port and then apply an inverted RxD to the RST pin. The start bits become the pulses.

Erik - If you can come up with a simplified circuit that you are willing to share with other Flash Magic users, then I can add support for your circuit into Flash Magic. Just let me know the timing requirements of DTR and RTS. Bear in mind the limitations of Windows applications when producing such waveforms.
Also take into account that opening and closing the COM port by Flash Magic usually (but not guaranteed!) results in DTR and RTS returning automatically to inactive states momentarily - while the COM port is closed it isn't under Flash Magic control.

[erik malund]

I took a hard look on the application (processing a keypad and some switches for IIC transfer to the 'main' processor) and decided to skip ISP and go parallel since the [cost of IIC components] vs [likelyhood of field upgrade required] equation came out as no ISP.

Erik

[Serg. Svatkov]

Dear authors of Flash Magic.

Thank you for this product. It is very convenient.
I have Flash Magic ISP experience with microcontrollers P89LPC932 and P89C51RD+.
And I will be glad if you will carry out my wish in your further versions of Flash Magic.

Our problem.
To avoid galvanic coupling we use photon-coupled pairs on TXD and RXD. For powering these pairs on PC side we use DTR and RTS. So serial exchange works well. But, for ISP, we made second connector because of  DTR and RTS are not accessible in Flash Magic. Can  you make some overpatching in

[Andy Ayre]

So you are not using the ISP hardware entry method, correct?

[Andy Ayre]

Erik,

You could probably build a small programming adaptor that contains the Keil circuit and plugs onto a header on your actual production hardware. At least then you can reprogram units that come back if you need to.

[Serg. Svatkov]

Hi, Andy.

Yes, I am not using the ISP hardware entry method in this case. It is device, which translate RS232 to our self-made interface. I debug my program. It is convinient to download it (frequently) and run excange (RS-232 to our interface) without any commutations of cables.

Serg.

[erik malund]

You could probably build a small programming adaptor that contains the Keil circuit and plugs onto a header on your actual production hardware. At least then you can reprogram units that come back if you need to.
I am going to use a socketed PLCC.  The reprogramming for this application (keyboard interface) will be just those few 932s that happen to have "lost their mind"

Erik

[Andy Ayre]

Serg - so you need DTR and RTS asserted while Flash Magic has the COM Port open, correct?

[Serg. Svatkov]

Andy - Yes.

Serg.

[Andy Ayre]

Serg - I will look into asserting RTS while the COM port is open and an LPC9xx is selected for the next release of Flash Magic.

[Andy Ayre]

Serg - sorry, that feature didn't make it into 1.89, but I will try to get it implemented in the next release.

[erikm]

Will this work as a NoTouch implementation for the LPC932

after I execute
mov a,#2
mov r5,#1
mov R7,#3
lcall 0ff00h
the program hums happily till the next power-on-reset after which it is in 'virgin chip boot mode' i.e. it will expect and accept FlashMagic input.

Also, in that mode will FlashMagic work since no power-on-reset feedback?  so a simple Rxd/Txd 232 chip (externally) connected to the PC is all that is required?

please confirm

Thanx,

Erik

[Andy Ayre]

Looking at the datasheet, I think that piece of code will work fine.

Flash Magic will work because it only communicates with the device when the user tells it to.

[erikm]

Thanks, so now we have NoTouch for the 932, great.  I'll design them in as SMT, not socketed.

Erik