Re: [uCsimm] cs8900 & wait-states

From: Tom Walsh (tom@cyberiansoftware.com)
Date: Wed Dec 06 2000 - 07:25:56 EST


daniel haensse wrote:
>
> Hi
>
> in the file uCcs8900.c in function cs89x0_probe1 I have found
>
> *(volatile unsigned short *)0xfffff112 = 0x01e1; /* 128k, 2ws, FLASH, en */
>
> why do we use six wait-states to access the device?
>
> Dani
> This message resent by the ucsimm@uclinux.com list server http://www.uClinux.com/

You will have to use 1 wait state as the cs8900 has an access time of
135ns and the DragonBall (16mhz) has a 100ns access time for Data
Valid. An additional wait state may have to be thrown in to allow for
any additional signal settling, although the 163ns access time of the
DragonBall @16mhz 1ws should be enough.

TomW


-- 
Tom Walsh - WN3L - Embedded Systems Consultant
'www.openhardware.net', 'www.cyberiansoftware.com'
"Windows? No thanks, I have work to do..."
This message resent by the ucsimm@uclinux.com list server http://www.uClinux.com/



This archive was generated by hypermail 2b30 : Sun Apr 07 2002 - 00:01:39 EST