公开(公告)号：JPH0357996A

公开(公告)日：1991-03-13

申请号：JP16007390

申请日：1990-06-20

Applicant: APPLE COMPUTER

Inventor： UENDERU SANDAA ,  BURAIAN SANDAA

IPC: G04F5/00 ,  G04F10/04 ,  G06F3/06 ,  G11B19/02 ,  G11B19/28

Abstract: PURPOSE: To improve the function of a front end, in particular, the function of time measurement thereof without the need of analog components by forming an integrated circuit with functions of a clock generation, read out output generation and written pulse generation. CONSTITUTION: The controller front end 6 is constituted of a clock generator 11, RDDATA time detector 15, and WRDATA time generator 19. The generator 11 receives a system clock signal from the 16MHzOSC of CPU, and generates a standard clock signal T1-T11 of 24MHz necessitating a required high resolution. Next, the detector 15 measures the position of an RDDATA signal generated by a disc drive controller 9 with use of the signal T1-T11, and generates a binary numeral RD4-RD0 with an accuracy 2ns representing the position. Also, in use of the signal T1-T11, the generator 19 converts a binary input number RD3-RD0 of 4ns increment generated by a disc drive controller 8 into a WRDTA signal. Thus, the measurement of time can be conducted correctly.