who has tried over clocking the at89c51 in KEIL C? how fast can it go? 10% 20% 100%? post your results.
Why bother? Does this world have too few natively faster processors at a decent price?
Why would that make any difference??
Exactly! That's why I keep wondering why 8051 is not dead yet. Now, imagine that you are stuck with a 8051 for some reason. What if you wanted to squeeze that extra little bit of performance out of it? I know: good software design, optimization and all. But still...
i will try liquid cooling [with water?????] and tell you my results.
You should also try the 22 nm CMOS technology. I hear it may allow you to run in the GHz range.
Liquid cooling is only relevant if the chip is overvolted. At stock voltage, it is likely to hang (or produce incorrect results) long before it gets hot enough to care about that extra cooling.
If not, then it is way better to use a TEC (Peltier) and run the chip at sub-zero temp - a lower temp makes a chip faster.
The thing to remember with a 8051 chip is that it hasn't any PLL. So can't just reconfigure to try higher and higher speeds. You either need to replace the crystal, or connect a programmable oscillator instead of the crystal.
Now, imagine that you are stuck with a 8051 for some reason. What if you wanted to squeeze that extra little bit of performance out of it?
The first step might be to pick a faster, more modern 8051 derivative than that antique the OP mentioned.
Why stick to the outdated 8051 architecture when a much more capable Cortex M0 based chip is as cheap!?
you all want to doubt my reason.
My application will contain a TCP/IP stack using an external ethernet module enc28j60 with web 2 servers and a TCP server, a 4 lines LCD, a TFT display with touch screen, a wav player, an IR RC decoder, a 2 phase rotary encoder, serial port interface, an SD card with NTFS file system. I use also 2 expanders 23S17 for the LCD and the TFT display (320x240@65K colors).
So i need as much speed as i can get.
For this kind of hi-speed device I suggest using a 4004. If one is not enough, use several in paralell.
So don't faff about with marginal increases from dodgy techniques!
Get a processor that is properly specified for a suitably high speed!
As already noted, 8051 derivatives are available with clock speeds of 100MHz !
And ARM Cortex-M processors offer greater performance still - and, probably, at a lower price!!
"I use also 2 expanders 23S17"
Another reason to choose another derivative (or another architecture) - one which has the required number of IOs without messing about with expanders!
"So i need as much speed as i can get"
Ever heard the expression, "work smarter - not harder"...?
I like "going nowhere fast" better...
going to another processor is not possible and i have no time for a big learning curve.
And yet you have time to faff about with overclocking - and all the weird & wonderful effects that can bring...?!
FAFF OFF