Re: [avrdude-dev] USART1

[Brian Dean]

On Sun, Apr 27, 2003 at 03:44:01PM -0700, Erick Castillo wrote:

> that USART1 has the pins for MOSI and MISO for serial programming. Will I
> still be able to program the atmega128 if I program it to use USART1 at
> port E? Will i have to go through some special procedure to program the
> chip again if I'm using USART1 for other things during operation?

Mainly you'll want to design your external circuitry so that it does
not interfere with ISP programming, whether this be through manual
jumpers that can be removed during programming, or by using logic to
respond to the /RESET signal which disables (goes to high impedence
state) any circuits that share the ISP lines.  For example, if you
plan to use an RS232 level shifter on the PORTE uart, consider using a
MAX3222, for instance, which has ENABLE and SHUTDOWN lines that can be
interfaced to the /RESET line.

-Brian
-- 
Brian Dean
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http://www.bsdhome.com/
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