US 5,479,619 A · Peripheral equipment control device

Abstract

A peripheral equipment control LSI interposed between an SCSI bus connected to a main CPU and peripheral equipment such as a file device. The LSI is divided into two major blocks. One block recognizes an SCSI protocol ID signal sent over the SCSI bus. The other block generates a signal that causes the other block to leave a sleep state (low power dissipation mode). In a sate in which a command is awaited from the main CPU, the peripheral equipment control LSI allows the block containing the ID recognition part to remain active while the other block is kept in the sleep state. On receiving an ID-based selected (access) signal from the main CPU, the LSI detects the start of an access operation and causes the other block to leave its sleep state and to become active.

Claims21

Dependent claims

A peripheral equipment control device connected to an interface bus which is connected to processing means including a processor and other peripheral equipment control devices, said peripheral equipment control device comprising:

a power supply for providing power by a power line and ground line;
a bus control unit for controlling a plurality of signal lines of the interface bus and a plurality of signal lines of an internal bus in said peripheral equipment control device;
a first group of terminators using resistors connected between each of the signal lines of the interface bus and the power line, the resistors having a resistance greater than 220 ohms;
a second group of terminators using resistors connected between each of the signal lines of the interface bus and the ground line, the resistors having a resistance greater than 330 ohms;
and
a central processing unit for controlling a piece of peripheral equipment according to a signal from the signal lines of the internal bus,
wherein said bus control unit drives the signal lines of the interface bus terminated by said first group of terminators and said second group of terminators.

4 more elements

a power supply for providing power by a power line and a ground line;
a bus control unit for controlling a plurality of signal lines of the interface bus and a plurality of signal lines of an internal bus in said peripheral equipment control device;
a first group of terminators using resistors connected between each of the signal lines of the interface bus and the power line, the resistors having resistance greater than 220 ohms;
and
a central processing unit for controlling a piece of peripheral equipment according to a signal from the signal lines of the internal bus,
wherein said bus control unit drives the signal lines of the interface bus terminated by said first group of terminators.

3 more elements

a power supply for providing power by a power line and a ground line;
a bus control unit for controlling a plurality of signal lines of the interface bus and a plurality of signal lines of an internal bus in said peripheral equipment control device;
a first group of terminators using resistors connected between each of the signal lines of the interface bus and the ground line, the resistors having a resistance greater than 330 ohms;
and
a central processing unit for controlling a piece of peripheral equipment according to a signal from signal lines of the internal bus,
wherein said bus control unit drives the signal lines of the interface bus terminated by said second group of terminators.

3 more elements

Dependencies are inferred from the claim text.

Peripheral equipment control device

Life of this patent

Peripheral equipment control device

Life of this patent

Abstract

Claims21