PERIPHERAL SEMICONDUCTOR DEVICE OF CENTRAL PROCESSING UNIT

摘要

PURPOSE:To attain a synchronous action with the clock of the same phase without generating a clock skew by providing an input/output buffer with a built-in noise removing circuit. CONSTITUTION:A signal clock A generated by a crystal oscillator 2 and outputted to a line 4 is supplied to a line 7 to a CPU 8 of the external part of a semiconductor device 1 as a clock signal B through an input/output buffer 6. At the same time, the clock signal B is supplied on a line 9 through a noise removing circuit 10 in the input/output buffer 6 to a function cell 3 in the semiconductor device 1 as a clock signal C. Thus, the clock skew of the clock signal B and the clock signal C supplied to the function cell 3 and the CPU 8 can be eliminated by supplying the clock signal A generated by the crystal oscillator 2 to the function cell 3 of the internal part of the semiconductor device 1 and to the CPU 8 of the external part through the input/output buffer 6 with the built-in noise removing circuit 10.