RE: [avr-libc-dev] Calls to eeprom_write_block on CAN64 increase sleepcurrent?

[Weddington, Eric]

> -----Original Message-----
> From: 
> address@hidden 
> [mailto:address@hidden
> org] On Behalf Of Bob Paddock
> Sent: Thursday, May 14, 2009 12:25 PM
> To: address@hidden
> Subject: [avr-libc-dev] Calls to eeprom_write_block on CAN64 
> increase sleepcurrent?
> 
> I'm using a AT90SCAN64 part.
> 
> Normally my system has a nominal sleep current of 67uA.
> 
> I added some logging routines to record some data in EEPROM.
> When I call eeprom_block_write() my system sleep current jumps
> up to 1.1 mA.  Comment out the call to eeprom_block_write() and
> the sleep current goes back down.  Whats going on here?
> 
> By 'sleep' I mean no oscillators running, and the watchdog turned off,
> everything should be static.
> 
> Is the call to eeprom_block_write() leaving some internal 
> oscillator running?

So you're saying that the current goes up to 1.1 mA and *stays there*, even 
when the eeprom write is finished? I'm assuming that you're going back to sleep 
after the eeprom write. Can you elaborate on the exact chain of events?


> Also when looking at eeprom.h I noticed that _EEGET and _EEPUT
> for IAR compatibility only have a single underscore.  In my ancient
> IAR version, from ~2005, those functions had double underscores.

That's been fixed recently in avr-libc. It'll be in the next release.