The serial communication device, serial communication manner, in the serial communication device which the data sending and receiving

摘要

PROBLEM TO BE SOLVED: To speed up communication by reducing the rounding of a waveform which occurs when a signal line is released.;SOLUTION: The control signal line 305 of a printer controller is connected to the input terminal of a three state buffer 303, and the control signal line 305 is also connected to the D input terminal of a flip flop 602 operated by an FFCK clock. The Q output signal of the flip flop 602 and a control signal SCO are inputted to an AND gate circuit 603, and the gate output signal is inputted to the control terminal of the three state buffer 303. Thus, the level of a data signal line 301 is changed from a level 1 to the level 702 of output in synchronizing with the rise of the level of the control signal line 305. Then, the data signal line 301 becomes a release state in synchronizing with timing when the FFCK clock rises.;COPYRIGHT: (C)2002,JPO