AVR-Chat

Hi Dennis,

Thanks for the reply to my query.

I do not wish to revisit the debate on the RET and RETI stuff, and also
do not wish to provoke a lot of debate on the GPIORx either, but in my
copy of the Atmel Data Sheet (just updated my copy tonight), 2545F dated
06/05 (and it said the same thing in my older year old version):

page 24: General Purpose I/O Registers within the address range 0x00 -
0x1F are directly bit-accessible using the SBI, CBI, SBIS, and SBIC
instructions.

page 337: shows GPIOR0 at 0x1E (which implies it IS bit-accessible using
SBI, etc.) and it shows GPIOR1 at 0x2A and GPIOR2 at 0x2B (which implies
is IS NOT bit-accessible using SBI, etc.).  I believe this is what you
found, isn't it?

Don

PS - as a side note, it is interesting that at least my PDF reader
program will not allow "copy & paste" of text in this datasheet ;-)

Dennis wrote:
> The GPIOR0, 1 & 2 do not all respond to the instructions specified. Only 
> GPIOr0 does. I use the LDS and STS with all 3.
> If you look at the RET and RETI instructions, the stack operations are the 
> same, according to the manual. However, the RET does return to the 
> instruction following the CALL whereas the RETI returns to the instruction 
> at point of interrupt. In the case of the RETI, after much debate and RTFM 
> bull, you have to use a polled type of interrupt.
> D
> ----- Original Message ----- 
> From: "Don Jackson" <ae5k.radio@gmail.com>
> To: <AVR-Chat@yahoogroups.com>
> Sent: Wednesday, August 31, 2005 8:51 PM
> Subject: Re: Re: [AVR-Chat] Errors in manuals ...
> 
> 
> 
>>Dennis wrote:
>>
>>
>>>>>Data sheet definitions are sometimes wrong as are manuals. I found that
>>>>>out
>>>>>the hard way with the mega168.
>>>>>....
>>
>>Would you be so kind as to let us know what is wrong in the mega168 data
>>sheet?  I'm about to use this one...
>>
>>Thanks,
>>Don