Hi Anil,

I wonder, which adc you want to use. Since all ADC, which I know accept a wide range of conversion frequency and no need for an accurate 1MHz clock.

E.g. I use the AD7890, which works from 100kHz up to 2.5MHz. And no permanent clock was needed. Only 15 clock cycle after sending the start conversion command.
So my solution was to do it in software:


CLR EA
REPT 15
CLR CCLK
SETB CCLK
ENDM
SETB EA

This give about 460kHz on using 11.0592MHz crystal.


Peter