CONTROLLER FOR PARALLEL INTERFACE AND CHANGE DETECTING DEVICE FOR DATA LINE

PROBLEM TO BE SOLVED: To speed up control over data transfer by a bidirectional parallel interface by altering and storing mode data according to an interface protocol and controlling the handshake corresponding to the mode through hardware. SOLUTION: This device is equipped with a basic control process part 1 which performs processes in mode discriminated from a sequence of parallel interface signals, an edge detection part 4 which detects changes of a control signal for an interface, a mode storage part 2, a trigger part 3 which is driven by the basic control process part 1 to generate a trigger, and a timer part 6. Then one of outputs from the trigger part 3, edge detection part 4, and timer 6 is sent to a host according to a mode select signal from the mode storage part 2 to generate handshake pulses. The basic control process part 1 alters and stores the mode data according to the interface protocol and controls the handshake corresponding to the mode through the hardware.