Simultaneous use of USARTs and SPI on ATmega64

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Dear All,

I guess a lot of you are using the AVR range of devices, so hope the answer
to my question below will seem straightforward.

The hardware engineers on my team wish to use the ATmega64 in a design we're
working on. I'm the software engineer. The design relies on having 2 UARTs
and and an SPI bus available simultaneously. On paper, this processor seems
to provide this. However, I'm concerned that some of these functions may be
multiplexed, i.e. can only have 2 UARTs and no SPI, or 1 UART and SPI
present.

The data sheets are a little vague on this. Can anyone shed some light on
this?

Very many thanks in anticipation!

Kind regards,

Clive Wilson



Re: Simultaneous use of USARTs and SPI on ATmega64
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answer
we're
seems
be

Well, a quick glance at the datasheet reveals that RXD0, TXD0, RXD1, TXD1,
MOSI, MISO and SCK all have their own pins. Not much of a problem then...
:-)

Meindert



Re: Simultaneous use of USARTs and SPI on ATmega64


<snip>

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OK, thanks. After having posted I took another, more careful look, and
realised I was panicking unnecessarily.

Thanks anyway,

Clive Wilson



Re: Simultaneous use of USARTs and SPI on ATmega64

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TXD1,
then...

Better panic now then when everything has been designed and changing things
is far more costly ;)

Jeroen



Re: Simultaneous use of USARTs and SPI on ATmega64
says...
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There are other issues to consider than whether SPI and USART have
separate pins.   That is true on the MSP430, but internally, both
modes use some common registers.   That can make it difficult
to use both the SPI and USART in anything except polled mode operation.

If you are going to rely on interrupt-driven I/O for the USART, you
may not have the freedom to switch modes between SPI and USART without
risking the loss of incoming USART data.

Mark Borgerson


Re: Simultaneous use of USARTs and SPI on ATmega64
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TXD1,
then...

After everything else fails, read the instructions ;-)
I think this should work fine.

--
Best Regards,
Ulf Samuelsson
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Re: Simultaneous use of USARTs and SPI on ATmega64

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Or, as an acquaintance of mine puts it: "RTFM?  You must be kidding.
Real engineers only refer to documentation if the keyboard-shaped
dents in their forehead become too obvious."

--
Hans-Bernhard Broeker ( snipped-for-privacy@physik.rwth-aachen.de)
Even if all the snow were burnt, ashes would remain.

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