P89C52 Hangs!!

all good stuff.

The contract manufacturer has very robust procedures, *but* this was the last of some oddball bits the customer had supplied. Grrr.

The funny part is the CM has *no* 0603 10nF caps anywhere. Alas it was a week between the smt run and PCB testing, so the empty reel is gone, and we cant figure out who mis-marked it.

Ah, the joys of smt manufacturing.

Cheers Terry

I'm out of it for now, but I remember all the headaches of hand placed parts 288 lead ICs turned the wrong direction, and one PCB layout person who used the mirror image for SOT23 (SC 59?) transistors way too often, then wanted the assemblers to bend the leads and mount the transistor face down. Not to mention the idiot who left the unused inputs of some CMOS nand gates floating which put a 5 volt, 27 MHz signal in the otherwise clean AGC system. :(

--
Service to my country? Been there, Done that, and I\'ve got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

OTOH that sort of thing provides opportunities for those of us who are not cursed with incompetence.

Cheers Terry

It got to where I would clear out the whole engineering department by storming into their wing and waving a schematic. They didn't know who I was after, but they ran like rabbits at the sound of a shotgun. ;-)

OTOH I found it a little odd that they put the best engineer into a tiny office away from everyone else. I only caught him in one mistake in four years. Some of the other engineers were visited weekly! ;-)

--
Service to my country? Been there, Done that, and I\'ve got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Hello Joe,

I always wonder how stuff like that passes design reviews at the chip manufacturers. It's pathetic.

He who trusteth on-chip POR (or even some BOR) circuits will see many a sleepless night, tossing about in agony.

--
Regards, Joerg

http://www.analogconsultants.com

[snip]

Unless the POR be designed by me ;-)

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | |

| 1962 | I love to cook with wine. Sometimes I even put it in the food.

OH!

Check the Philips LPC900 Applications Notes for an App note on Oscilators for your P89LPC952

JG

Hello Jim,

:-)))

However, you wouldn't ever design anything but a BOR, would you?

The worst stuff are those edge triggered schemes. In design reviews these drive me up the wall but, of course, as a consultant one has to resist the urge to crack nasty jokes about it. Has to be more like the Japanese style "Very nice design but I'd suggest a slight mod over there...".

--
Regards, Joerg

http://www.analogconsultants.com

Dammit Jim, why cant you do some for Xilinx. Its pretty clear they cant.

Cheers Terry

Hi,

I tried the TPS3707 as a reset, i got a 200msec high as an output still the microcontroller works 3 out of 4 times.. Is there i can do in the code??

Thanks and regards,

Nick

Hi,

I tried the TPS3707 as a reset, i got a 200msec high as an output still the microcontroller works 3 out of 4 times.. Is there i can do in

the code??

Thanks and regards,

Nick

You really need to supply some more detailed info.

Relatively unlikely I reckon.

Graham

its not so much the duration of the reset, as whether or not the oscillator is up and running before the device comes out of reset. which depends on the oscillator as well as the reset.

look at the TUSB3210 datasheet on the TI website.

HTH

Cheers Terry

The 8031 family clock oscillator's pretty reliable ! I've never seen that problem as such.

It might be agood idea to check the crystal load capacitance though. I've seen the clock oscillator completely fail to start up when my mates subbed the wrong value !

Graham

betcha they dont use the same processes anymore. nor do different manufacturers necessarily use the same process.

yep. easy to cook, too.

Cheers Terry