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RE: synchronous port : clock rate in slave mode



warp_mode only works in master output mode (again if I remember correctly).

-----Original Message-----
From: owner-dev-etrax@xxxxxxx.com">mailto:owner-dev-etrax@xxxxxxx.com] On Behalf Of Mathieu Berland - 77160
Sent: Monday, June 23, 2003 1:35 PM
Cc: dev-etrax
Subject: Re: synchronous port : clock rate in slave mode


You're right but in the datasheet page 19-347 it is said : "if warp_mode is enabled, the codec base clock is changed from 4.096MHz to 12MHz. This is only used for testing purposes".

What does it means :
1) This is only a alternate clock and the maximum rate is still 4.096MHz altough it is possible to go beyond with clock divisor < 3 ?
2) The hardware can handle frequency till 12,5 MHz but it is not guaranteed beyond 4.096 MHz ?




Mikael Starvik wrote:

> Hi,
>
> If I remember correctly you should not use an external clock > 4.096 
> MHz so I don't think 12 MHz is usable.
>
> /Mikael
>
> -----Original Message-----
> From: owner-dev-etrax@xxxxxxx.com">mailto:owner-dev-etrax@xxxxxxx.com] On 
> Behalf Of Mathieu Berland - 77160
> Sent: Monday, June 23, 2003 11:13 AM
> To: dev-etrax
> Subject: synchronous port : clock rate in slave mode
>
> Hi,
>
> I'm trying to use the synchronous serial port 0 in slave 
> bidirectionnal mode. The external data clock rate is 12MHz. The 
> external frame sync clock rate is 8KHz.
>
> When I send data from the devboard, the bit stream only syncs on the 
> frame sync signal at 8KHz but not on the clock signal at 12MHz. The 
> clock signal looks not very good, it's not a square signal but a sinus 
> signal.
>
> Before designing a transceiver for the external data clock, I'd like 
> to be sure that the etrax hardware can handle a clock at 12MHz.
>
> Thank you,
> Best Regards.