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AVR AT90S1200 Speed ? Need help

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Jan 25, 2002
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at90s1200 instruction


I am going to build a project need a fast uC. { Canal+ PAYTV Decoding }
I fimiralr with AT89C2051 but with each machine cycle, it takes 12 oscillator or clock cycles.

So if the crystal is 24Mhz {max} the time per instruction is 0.5 us {too large}

and i fimilar with PIC16f84 too but also with each machine cycle, it takes 4 oscillator or clock cycles.

I read about AT90S1200 .
Does this uC operate at faster speed ?
What is the min. instruction time ?



Hi Pharaoh of Egypt!

If you are familiar with 51 series of processor then you can use AT89C51 of Atmel - I have used this crystal on 34 MHz with external generator. So, you will have (1/34000000)*12=~0.35 uS per instruction.

PIC16F84 has 4 takts per instruction, so if you have 20 MHz pic, then you will have (1/20000000)*4=0.2 uS per instruction.

If you will need more quickest processor, then use AT90S1200 or better AT90S2313 it is working on 10 MHz (even up to 12 MHz) - you will have 1 takt per instruction, so it will be 1/10000000=0.1 uS per instruction.

If it is too slow for you, then get Scenix (Ubicom) microprocessor - it has 1 takt per instruction and is working up to 75 MHz (or even up to 100 MHz in some conditions), so it will be: 1/75000000=13 nS per instruction.

If you are going to make decoder like 3chip, then best choise will be AT90S2313. It has enough power and memory to decode Tocom's style TV signals (I mean SSAVI coding).

Best Wishes! klug.

clock at90s1200

Hi there,

Great Thanxxx :)

AT90S2313 is better for me.
My homebuilt AT89CXXXX programmer can program it .

Pharaoh 8) Of 8) Egypt

avr at90s1200

If you don't use the EEPROM inside AVR 1200 or 2313 you can easy "overdrive" them. I make some tests with an AT90S1200 at 24 MHz and it worked. It's true that it was from some of the first revisions, that was designed to work at 16 MHz. Now the specs are for 12 MHz maximum.

Need for speed

Hi There,
I did overclock ATMEL ATMEGA8 @28.2Mhz. 1 clock =35.5ns.
This is fast for 8 bit micros. There is another Vendor caled UBICOM. They do have 8 bits micros running at 100MIPS. Some of their micros are 100% code compatible with PIC16C54 micros.

I agree that AVR series is very fast and i use it too but you can use ds80c310 from dallas which is mcs8051 compatible BUT it executes one instruction per 4 clock cycles which means that with a 33MHz crystal you can have 8.5MIPS!!!

You can find its manual at **broken link removed**

I think but i am not sure that there is also another mcs51 compatible microcontroller (i do not remember the manufacturer) that can accomplish one instruction per ONE clock cycle. You should search for it

I hope that i helped a little

P.S. I think that someone of you guys is frome Greece. If so...

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