Re: AT91RM9200 and AC97 codec - not recommended ?

Pelos wrote:
Hi everybody.
I'm finishing my RM9200 board (32MB SDRAM, 2MB SPI NOR, Smart Media,
RTL8201).
Now I need to choose te audio interface.
First - I was thinking about AC97 codec - like National's LM4549
because I saw this chip in some RM9000 SDK boards.
But I saw some posts with information that AT91RM9200 and its SSC
doesn't work with AC97 codec.
Can somebody confirm (or better not ;) ) this fact ?
So... AT91RM9200 and audio interface - only one solution it is i2s
codec ? Am I right ?


The AC-97 runs at 20 MHz+ and this speed is not supported by the
AT91RM9200.
Think it tops out at MCK/4 = 15 Mhz. Later chips have faster SSCs.
Also you need to run several timeslots, which is difficult to implement
even if you support the high speed.
The AC-97 peripheral used in the AVR32 AP7000 is now available for use in
future AT91 chips.

The I2S based AT73C213 Audio DAC has been used with the AT91SAM9261.


Best regards

--
Best Regards,
Ulf Samuelsson
ulf@xxxxxxxxxxxxx
This message is intended to be my own personal view and it
may or may not be shared by my employer Atmel Nordic AB


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