Multiple Single-Chip Communication Based on Parallel Print Port
SONG Hui (College of Computer Science, Southwest University of Science & Technology, Mianyang 621002, China)
For communication among parallel print port of PC and multiple single-chips, interface is divided into data, state and control groups respectively controlled by each register. Register was read or written, and data was input or output with outportb and inportb function of C language. PC sent signal via print control port and STROBE, encoder generated choosing signal and sent it to P3.2-end of single-chip to form interrupt. Single-chip sent back replacement signal through P1.0, and then PC sent again interrupt as far as transmission end. PC sent again choosing signal to second single-chip to transmit data until ended last single-chip.