http://www.analog.com/UploadedF...7866_a.pdf
the part is the ad7866 a dual 12 bit sar adc.again i am providing the serial clock via the 8051 by setting and clearing a port pin p3.2 repeditively 32 times.this is the only way of controlling the part as the data sheet requires that the sclk go low a specified time after the cs (start conversion which causes the front end sample and hold amplifier to sample the signal.(this means i must use a burst clock).i cannot think of any other way of generating the clock by software!