Re: [avr-chat] Differences between ATmega1284 and P version?

[Joerg Wunsch]

Ruud Vlaming <address@hidden> wrote:

> i cannot find the datasheet of the 644A, so i have no
> real comparrisson at the moment.

I don't think there is any ATmega644A, it's probably only available as
an ATmega644PA.

The ATmega644 vs. ATmega644P is IMHO the only time where the suffix
letter actually indicated two different feature sets (with/without
second USART).

The "A" devices are die-shrink versions, where all the connections
have been routed with smaller traces, yet retaining the original
transistor structure sizes (to avoid different electrical behaviour
compared to the non-A versions).  This leads to somewhat faster ICs,
so the original distinction between two speed vs. voltage device
classes (L/V devices vs. devices without that suffix) became obsolete
with the A devices.

-- 
cheers, J"org               .-.-.   --... ...--   -.. .  DL8DTL

http://www.sax.de/~joerg/                        NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)