HOW TO set philips 89c51RB2/RD2/RC2 IN 12 machine cycle mode

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ronydc

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deaer friends..

HOW TO set philips 89c51RB2/RD2/RC2 IN 12 machine cycle mode ..?

bcs the noramal operation if this ic's is of 6 machine cycles. so thay are of double speed thn conventional 8051.
but if user requires it can be set to 12 cycle mode....
how to do this ....
can any one show the way please..?

thanks..
RONY.
 

Re: HOW TO set philips 89c51RB2/RD2/RC2 IN 12 machine cycle

during set up include this line:

Code: 
MOV	CKCON,#001H		;Select X2 mode

or

Code: 
MOV	CKCON,#000H		;Select regular mode

that should do it for the RD2 at least.
Look at the datasheet for the device you are using.
 

Re: HOW TO set philips 89c51RB2/RD2/RC2 IN 12 machine cycle

thanks for your helpful reply sir.
1> If i am using C c
an i write ---> CKCON = 0X0F;
in the main{ ..?

2> IS THERE any hardware method to do the same.? any pin or anything....? so that every time it gets selected the 12 cycles mode.. even if not done in program by software. as the suggested way..?

rony

Added after 11 minutes:

sorry to all

in my previous reply there was a mistake in writing..

i should write..
-----> i am using C can i write CKCON = 0X00 ; ......?

AND IS THERE ANY HARDWARE WAY TO DO SO.?

THANKS
AND SORRY FOR THE MISTAKES I MADE IN WRITING.

PLEASE GUIDE ME

RONY.
 

Re: HOW TO set philips 89c51RB2/RD2/RC2 IN 12 machine cycle

ronydc said:
thanks for your helpful reply sir.

-----> i am using C can i write CKCON = 0X00 ; ......?

AND IS THERE ANY HARDWARE WAY TO DO SO.?

RONY.
Click to expand...

If you do NOTHING, it will be in "12 clocks per machine cycle" (standard mode) by default.
You will have to set X2 bit in CKCON only if you want x2 mode.

In other words, by default, the CKCON register is 0x00 at startup, unless it it is written to by your software.

You can also set the x2 bit in the HSB when you program your device. This setting overrides the CKCON setting, and is checked at startup.

Again, it is set to standard mode by default, you only have to change it if you want x2 mode.

I use both the AT89C51RD2 and the AT89C51ED2, they are both incredible devices that are loaded with lots of features!

Best of Luck To You
 

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    ronydc

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sir ur answer really helped me.

i feel you are the real sea of knowledge. as i have seen your many previous posts and creations.

thanks a lot

Rony.
 

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