Dear All

What is the difference between hardware mode and software mode for AD7656. What is the advantage of hardware mode over software mode.

 

Where in the datasheet did you find this terms being explained?

 

ya I found that two modes of operation is existed in this device. One is hardware mode and software mode. In software mode we need to write the values in the control registers, but in hardware mode logical signals has to give for ADC control signals. for this explanation see the AD7656 data sheet.
page no. 18 ( software selection of ADC)

http://www.analog.com/static/imported-files/data_sheets/AD7656_7657_7658.pdf

 

In the hardware mode you select which analog inputs are to be sampled by applying appropriate signals to CONVST A, CONVST B, and CONVST C pins.
In the software mode, you preselect which analog inputs you want to sample and store them in the memory. When you choose to use the software mode the chip will read this memory and see which analog inputs have to be sampled.
You can choose between hardware and software mode by driving H/S SEL pin low or high respectively.
Read it carefully and you will understand how you use it.