Yeah... I just typed in the edit here on the forum. So much nicer to have the compiler catch that sort of typo! <G>

Now... back to re-edit.

Lloyd

Well, DAWM! I just discovered a bug in my code. The Disable routine below MUST NOT use XOR, unless an enable was done first. Otherwise, XOR sets the bit, rather than clearing it. It should read thus: sub BOD_Disable BOD_ISR = ADDRESSOF Do_Brownout_ISR ' DISable the BOD interrupt. VICIntEnable AND= (...

Ahhh... &H400FC180 (The RSID register) bit 3 contains a flag that is set when power voltage falls below the BOD trigger level. This register is defined in LPC17xx.bas as SCB_RSIR One could watch that bit with BOD interrupt disabled, then when it becomes set to a "1", enable the interrupts, and see w...

PS to Gary. If you have much to do to create your 'saved state', it would be reasonable to do it in a systick-driven or event-driven sub, rather than within the BOD IRQ, but with one limitation: Because it might be possible to get a BOD interrupt during your construction of the saved value, it would...

Here is the one interrupt routine, two subs for enable and disable of the IRQ, and a tiny pseudo-code example that sets up to use the pack_date discussed above. I'm good at forgetting the purpose of various statements I write , so there are MANY more comments than code... comments are 'free', even i...

Actually, bit 0 is the position the flag occupies in the hardware from which I read it, so it seemed natural to place it there. With the bit-shifting nature of that packing algorithm, one isn't limited to where the flag can go -- any bit; although it would require a couple more statements to pack th...

The BASIC on the LPC1756 isn't as fast as tight C code, but in the scheme of things, I'd calling "Blindingly Fast!!!". There's plenty enough time to pack that date AND do probably another 50 lines of code after it in the short time between a brown-out interrupt and the final stoppage of the CPU by t...

As part of this quest to save states when power fails, I needed to conserve memory, since there are only 20 bytes (5 integer's worth) of NVRAM in the RTC backup registers. "BOD" stands for "Brownout Detect". I'll document the interrupt method to employ it on the LPC17xx devices as time permits. Belo...

Yep... and with three stages of falling/rising supply detection, it provides a lot of detail on what's happening in the few tens of milliseconds as power is failing. In my scenario, I must both detect the falling supply, and read a couple of GPIO inputs to see if the problem was caused by a use hitt...

If you haven't already, give JEdit a try. It's very clean, simple, and never seems to upchuck on me.

LLoyd