公开(公告)号：SG86330A1

公开(公告)日：2002-02-19

申请号：SG1998002745

申请日：1998-08-04

Applicant: IBM

Inventor： TATSUYA SAKAI ,  MASAYUKI MURAKAMI ,  NAOYUKI KAGAMI ,  YUZO NAKAGAWA

IPC: G11B21/10 ,  G11B5/596 ,  G11B5/00 ,  G11B19/02 ,  G11B19/00 ,  G11B5/09 ,  G11B5/55

Abstract: A disk drive, a servo controller, and a controller which have realized high-degree control by lightening processing load to a microprocessor unit (MPU) without increasing cost is disclosed. An analog/digital (AD) converter (ADC) performs the AD conversions of the regenerated levels A, B, C, and D of burst patterns supplied from a channel and retains the converted levels in an ADC register. A servo assist (SA) computes parameters, such as the position error of a head, independently of an MPU, based on the regenerated levels of the burst patterns retained in the ADC register and an instruction from the MPU retained in a SRAM. Based on the computed parameters, the SA computes servo data (DACOUT) for driving a voice coil motor and supplies the servo data to the DAC section of a VCM driver section through a SIO.

公开(公告)号：SG105481A1

公开(公告)日：2004-08-27

申请号：SG200100414

申请日：2001-01-29

Applicant: IBM

Inventor： HIROSHI OSHIKAWA ,  TATSUYA SAKAI ,  HIDEO ASANO ,  MASAHIKO SATO

IPC: G06F3/00 ,  G06F13/00 ,  G06F13/38 ,  H03K19/0175 ,  H03K19/0185 ,  H04L1/00 ,  H04L25/02 ,  H03K5/12

Abstract: The signal output device of the present invention comprises of a driver circuit and a controller. The signal sending method of the present invention sets any one of a plurality of the different sending rates. The method also includes setting a slew rate of the driver circuit to a standard value that is in accordance with the predetermined data transfer rate, thereby starting signal transmission. The next step involves determining whether or not a data transfer error occurrence rate is below a predetermined allowable threshold. Then, changes in the slew rate of the driver circuit are made if the data transfer error occurrence rate is determined to be over the allowable threshold. Next, a search for a slew rate value that can decrease the data transfer error occurrence rate below the allowable threshold or decrease the data transfer error occurrence rate is performed. The new slew rate value is set as a new standard value. Finally, the process ends by setting the new standard slew rate for the driver circuit if the slew rate value can decrease the data transfer error occurrence rate below the allowable threshold or decrease the data transfer error occurrence rate.