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Re: [avr-gcc-list] compiler not generating IO
From: |
Joerg Wunsch |
Subject: |
Re: [avr-gcc-list] compiler not generating IO |
Date: |
Thu, 26 Jan 2006 21:24:17 +0100 (MET) |
"developer2112 (sent by Nabble.com)" <address@hidden> wrote:
> I get in my listing:
> UDR = 'A';
> 272: 81 e4 ldi r24, 0x41 ; 65
> 274: 80 93 2c 00 sts 0x002C, r24
> clearly I am not getting an "out" instruction, what gives?
It will work anyway, only not as effective. Memory-mapped IO (MMIO)
is the only method where access to the entire set of IO registers on
the AVR can be guaranteed for all devices.
If you turn on optimization, the optimizer will recognize that
situation, and turn that into an "out 0x0c, r24" instruction.
--
cheers, J"org .-.-. --... ...-- -.. . DL8DTL
http://www.sax.de/~joerg/ NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)
- [avr-gcc-list] compiler not generating IO, developer2112 (sent by Nabble.com), 2006/01/26
- Re: [avr-gcc-list] compiler not generating IO,
Joerg Wunsch <=
- Re: [avr-gcc-list] compiler not generating IO, developer2112 (sent by Nabble.com), 2006/01/26
- Re: [avr-gcc-list] compiler not generating IO, Joerg Wunsch, 2006/01/26
- Re: [avr-gcc-list] compiler not generating IO, developer2112 (sent by Nabble.com), 2006/01/26
- Re: [avr-gcc-list] compiler not generating IO, Joerg Wunsch, 2006/01/26
- Re: [avr-gcc-list] compiler not generating IO, developer2112 (sent by Nabble.com), 2006/01/26
- Re: [avr-gcc-list] compiler not generating IO, Royce Pereira, 2006/01/26
- Re: [avr-gcc-list] compiler not generating IO, Joerg Wunsch, 2006/01/27