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Adaptively variable clock frequency method to satisfy both high performance and low power

IP.com Disclosure Number: IPCOM000015807D
Original Publication Date: 2002-Aug-21
Included in the Prior Art Database: 2003-Jun-21
Document File: 1 page(s) / 45K

Publishing Venue

IBM

Abstract

Disclosed is a method to realize both the high performance and the low power for HDD (Hard Disk Drive) by changing the clock frequencies of HDC (Hard Disc Controller) and MPU (Micro Processing Unit) in the servo process case and the other process case. The characteristics of this disclosure is to change the clock frequencies according to the required process capability. As the servo process requires the high process capability, the clock frequency of HDC and MPU is raised during the servo process. But on the other hand, as the other process does not require so high process capability, the clock frequency is kept low during this process. The low clock frequency results in the low power. As the servo process ratio is only 10% or 20% of whole process time, the power increases very little compared with 100% low clock frequency. By this method, the high performance and the low power are compatible It can be distinguished by the detection of the servo pattern on the disk whether the servo process or the other process is now being processed. When the servo pattern is detected, MPU is interrupted and can know that the servo process has begun. While MPU is executing the servo process, the clock frequency is raised to the high frequency, and when the process finishes, the frequency returns to the regular low frequency. By this method, the high performance can be realized with the low power. 1

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  Adaptively variable clock frequency method to satisfy both high performance and low power

Disclosed is a method to realize both the high performance and the low power for HDD (Hard Disk Drive) by changing the clock frequencies of HDC (Hard Disc Controller) and MPU (Micro Processing Unit) in the servo process case and the other process case.

The characteristics of this disclosure is to change the clock frequencies according to the required process capability. As the servo process requires the high process capability, the clock frequency of HDC and MPU is raised during the servo process. But on the other hand, as the other process does not require so high process capability, the clock frequency is kept low during this process. The low clock frequency results in the low power. As the servo process ratio is only 10% or 20% of whole process time, the power increases very little compared with 100% low clock frequency. By this method, the high performance and the low power are compatible

It can be distinguished by the detection of the servo pattern on the disk whether the servo process or the other process is now being processed. When the servo pattern is detected, MPU is interrupted and can know that the servo process has begun. While MPU is executing the servo process, the clock frequency is raised to the high frequency, and when the process finishes, the frequency returns to the regular low frequency. By this method, the high performance can be realized with the low...