US 5,475,814 A · Self diagnosis of a SCSI controller through an I/O port for data transmission/data reception modes of operation

Abstract

An I/O port enable to intercept the SCSI communications between a SCSI control circuit and host system regardless at the data transmission mode or at data reception mode. When the SCSI communications are intercepted, a system controller transfers data from a main memory to a buffer memory through the SCSI control circuit at the data transmission mode of the SCSI control circuit and performs the self-diagnosis of the SCSI control circuit by comparing data transmitted to the buffer memory with the test data stored in the main memory. At the data reception mode of the SCSI control circuit, the system controller stores data read from the main memory to the buffer memory through the buffer memory control circuit and performs the self-diagnosis of the SCSI control circuit by comparing data read from the I/O port with data stored in the main memory. Thus, it is possible to vest the self-diagnosis function to the disk control system comprising the SCSI control circuit as the communicating means with the host system so that to improve its liability.

Claims11

Dependent claims

A disk control system which controls data input and output between a host system and a disk storage device, the control system comprising:

A SCSI (Small Computer System Interface) control circuit which performs SCSI communication with said host system;
and
input/output (I/O) means, having a first I/O port connected to the host system via a first bus, a second I/O port connected to a second bus, the second bus being independent of the first bus, and a third I/O port connected to a third bus, the I/O means having
a first mode for interrupting the SCSI communication between said SCSI control circuit and said host system, irrespective of an active operational mode of the SCSI control circuit for data transmission and data reception, such that the I/O means functions as an input/output circuit for said SCSI control circuit to input and output data to and from the SCSI control circuit from the third bus using the second bus when the SCSI communication between said SCSI control circuit and said host system is interrupted, and
a second mode for establishing a connection between the first bus and the SCSI control circuit to permit communication between the host system and the SCSI control circuit.

2 more elements

A disk control system which controls data input and output between a host system and a disk storage device, the control system comprising;

a SCSI (Small Computer System Interface) control circuit which performs SCSI communications with said host system;
a SCSI bus connected to said host system;
an I/O port having a first port connected to said SCSI bus and a second port connected to said SCSI control circuit to selectively permit transmission of data between the SCSI bus and the SCSI control circuit;
a system controller bus connected to said SCSI control circuit and to a third port of said I/O port;
a buffer memory;
a buffer memory control circuit, connected between the system controller bus and the buffer memory, for controlling data input and output to and from said buffer memory;
a main memory connected to said system controller bus;
and
a system controller connected to said system controller bus, the system controller setting up said SCSI control circuit to operate in a data transmission mode or a data reception mode and setting up said I/O port to interrupt the SCSI communications between the host system and the SCSI control circuit, wherein the I/O port functions as an input/output circuit for the SCSI control circuit through the third port of the I/O port when the SCSI communications are interrupted.

6 more elements

Dependencies are inferred from the claim text.

Self diagnosis of a SCSI controller through an I/O port for data transmission/data reception modes of operation

Life of this patent

Self diagnosis of a SCSI controller through an I/O port for data transmission/data reception modes of operation

Life of this patent

Abstract

Claims11