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Simultaneous use of USARTs and SPI on ATmega64

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

Reply to
Anon
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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

Reply to
Meindert Sprang

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

Thanks anyway,

Clive Wilson

Reply to
Anon

"Anon" schreef in bericht news: snipped-for-privacy@giganews.com...

TXD1,

then...

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

Jeroen

Reply to
Jeroen

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

Reply to
Mark Borgerson

TXD1,

then...

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

--
Best Regards,
Ulf Samuelsson
ulf@a-t-m-e-l.com
This message is intended to be my own personal view and it
may or may not be shared by my employer Atmel Nordic AB
Reply to
Ulf Samuelsson

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 (broeker@physik.rwth-aachen.de)
Even if all the snow were burnt, ashes would remain.
Reply to
Hans-Bernhard Broeker

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