RE: TStik Multiplier and crystal speed

Platforms that run the 80C400 at 4X (74 MHz) do so by using fast SRAM without
battery back-up. They do this by using a flash memory that holds an image of
the RAM contents. At start-up, the system runs at 1X and copies the flash to
the SRAM, and then switches to 4X as it runs from the SRAM. This has
disadvantages in that any data that you want to be persistent through a reset
or power loss must be stored in the flash. (The file system is in RAM and so
goes away with each reset.) And, writes to the slower flash memory must use
stretch-cycles to do so, so native code is certainly required.

On the other hand, this makes for a highly reliable system because the RAM
code is restored from flash at every reset, so corrupted code in the RAM gets
fixed on every reset.

Chris



-----Original Message-----
From: tini-admin-6tN4nzCoH/[email protected] [mailto:[email protected]] On Behalf Of
Bruce Boyes
Sent: Monday, March 22, 2004 5:30 PM
To: Samuel Fruchter; tini-6tN4nzCoH/[email protected]
Subject: Re: [TINI]TStik Multiplier and crystal speed


At 07:24 PM 3/22/2004 +0100, Samuel Fruchter wrote:
>Hi,
>
>I saw that the TStik has a 75 MHz capable cpu.

The 80C400 is *capable* of 75 Mhz with 10 nsec SRAM for code and data. This 
memory is not practical as NVRAM (you'd need a motorcycle battery or a 
stack of D cells). There is no Flash memory fast enough, so such a system 
would not currently be able to use the standard TINIOS. Current available 
SRAM is 55 or 70 nsec access time, flash is 70 or 90 nsec.

So the C400 is *capable* of faster speeds but in all but specialized cases 
it isn't practical because there is no adjustment for the speed of code 
memory, and there is no practical high speed code memory.

In other words, it's marketing vs reality.

Regards

Bruce

>Why then the speed is only 29.4 MHz : multiplier is set to only 2 and 
>the crystal speed is 14.7 MHz (instead of 18.432 in the TINI) ?
>
>
>Sam
>
>
>_______________________________________________
>TINI mailing list
>TINI-6tN4nzCoH/[email protected]
>To UNSUBSCRIBE, edit your profile, or see list archives: 
>http://lists.dalsemi.com/mailman/listinfo/tini

------- WWW.SYSTRONIX.COM ----------
   Real embedded Java and much more
www.jrealtime.com and www.tstik.com
+1-801-534-1017  Salt Lake City, USA


_______________________________________________
TINI mailing list
TINI-6tN4nzCoH/[email protected]
To UNSUBSCRIBE, edit your profile, or see list archives:
http://lists.dalsemi.com/mailman/listinfo/tini


_______________________________________________
TINI mailing list
TINI-6tN4nzCoH/[email protected]
To UNSUBSCRIBE, edit your profile, or see list archives:
http://lists.dalsemi.com/mailman/listinfo/tini