Ahhh, the old watch crystal startup problem. I could tell you a bit about it but expect at least a second or more before it stabilises. When it comes to...
Thanks Peter. I certainly doesn't know this before. Bad low current watch crystal!! If I replaced it with a normal 32kHz crystal, will the wakeup time ...
Unless you had the datasheet on the crystal it's hard to say. But some things you need to "watch" for (unintentional pun) is to avoid excessive heat when...
Hi Ow Tong Peow, what about the following setup. You use the 32 kHz crystal as system clock and leave it on all the time (not the IRC, consumes more power ...
Dear Peter, My application is running off a battery CR1220. The constant output current is 0.1mA, which is very low. Capacity is 35mA. My team then decide on...
I'm a little confused. Why does your application need a crystal? All you need to do is to wake-up, update a counter, then go back to sleep. The IRC uses only...
Dear Peter, Yes, I could use IRC for a very fast start up and do some quick computation. But, the current consumption during active mode is more than 1mA. I...
Yes, have you measured the IRC startup time? It should be extremely short, certainly way less than the crystal option. There is still the DIVM there to reduce...
Dear Peter, Yes, the IRC time is really short. I love it. My application also has a RTC timer for counter. Is this possible? 1) Start Running on IRC. 2)...
Now I'm really confused. You are running an RTC with the 32k xtal, fair enough. But your earlier messages seem to imply that you turn off this oscillator and...
Just wanted to confirm there is a WDT oscillator nominal 400 kHz, very fast startup but wide tolerance (I think +/- 30 %). Use this with DIVM and you should...
Sorry for the confusion. I need doing this: 1) Power up, uP -> Power down mode. 2) On Keypad Interrupt (Low Level), Start RTC with 1 second interrupt. 3) Keep...
Dear all, Just found out something very interesting, which I could use as a workaround. Main Oscillator and RTC is using 32kHz watch clock When LPC901 goes to...
How about you startup on the IRC and calibrate the WDT against this, then run on the WDT wth DIVM. I would not think that a 32k xtal can really better this...
Hi everybody! I'm working on a time sheduler that counts the seconds based on January 1, 2000 in order to represent the actual time and date using the Keil...
Hello J. What have you done with the watchdog? For your reference the watchdog is enabled at reset (even if the WD reset is disabled in UCFG1) and will...
Hello J, In addition to my other comments check these points (these are general comments for all users of the RTC): - Clear the watchdog oscillator enable to...
Hello PM, Thanks a lot for your advise. Yes, I will have a hardware watchdog externally (comes up after 2 seconds). The RTC initialization routine is as...
I am conducting some research into real time applications in small systems. In particular I am interested in applications that employ an RTOS on an 8 bit...
Some days it just doesn't pay to get out of bed ... but I think I had some luck today and killed the beast. Puuhh ... after some deep investigation: Loosing...
Hi I had a problem during startup. LPC932 Hangs during startup whenever there is a Mains power failure or while switch on the device. This happens 2 out of 10...
Hi Dot, please get a LPC932-A1, which has been the current version for about 6-9 months now. If it still happens , post again. Background: the original LPC932...
Ian, a small program / hardware (less than 16k) could be heavily overloaded with a real time OS. The smallest I am aware of are the RTX from Keil and CMX...
... I agree and I expect to find few if any applications using an RTOS in such applications. The smallest I am aware of are the RTX from Keil ... Those two are...
Hi Bob, Thanks for the support. I'll try to get LPC932A and try again. Unfortunately I got 30 nos of TSSOP stuff with me. Here in Chennai (India), I could not...
If you use brownout to generate reset this problem can be sorted out Pragnesh. ... From: <lpc900_users@yahoogroups.com> To: <lpc900_users@yahoogroups.com> ...
Has anyone done up an assembler header file for the LPC903's? Sure would save typing in all those registers etc. If you have a sample init file then even...
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the lpc900_users group. File : /MOD935 ...
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Mar 6, 2005 8:03 pm
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