Software drivers for the reconfigurable ASIC analogue front end

The reconfiguration of the analogue front end of an intelligent sensor ASIC is implemented by means of analogue switches under digital control. A simplified diagram that concentrates solely on switching circuitry is shown. The configuration of this sub-system is determined by a vector of noughts and ones, which wholly determines its state. In an experimental version there are sixteen such switches, so any given state of the sub-system can be represented by a 16-bit word, that can be stored in a register-mapped memory space of the controlling digital processor. This is advantageous, as it permits a number of standard configurations to be stored and quickly implemented. Thus the sub-system can be switched into a self-check or self calibration mode with very few control instructions.