Method and structure for supporting flow control by a SCSI target during the data out phase of the packetized SCSI protocol

• US 6,842,798 B1
• Filed: 12/20/2000
• Issued: 01/11/2005
• Est. Priority Date: 12/20/2000
• Status: Expired due to Fees

• Current Assignee: PMC-Sierra Incorporated (Microchip Technology Incorporated)
• Original Assignee: Adaptec Incorporated (Steel Partners Holdings LP)
• Inventors: Young, B. Arlen
• Primary Examiner(s): VINCENT, DAVID ROBERT
• Application Number:
  US09/745,036
• Time in Patent Office: 1,483 Days
• Field of Search: 370/36, 370/33, 370/35, 370/100, 370/104, 370105- 7, 370/359, 370/389, 370/392, 370/402, 370/409, 370/419, 370/431, 370/438, 370/458, 370/463, 370/498
• US Class Current: 710/36
• CPC Class Codes: G06F 13/4226 with asynchronous protocol

Abstract

A flow control method performed by a SCSI target includes receiving a data packet information unit in a Packetized SCSI Protocol Data Out phase. The SCSI target also generates a signal during said Packetized SCSI Protocol Data Out phase to indicate whether another data packet information unit is to be transmitted in said Packetized SCSI Protocol Data Out phase.

Claims

1. A method comprising:

receiving, by a SCSI target, a data packet information unit in a Packetized SCSI Protocol Data Out phase; and

generating a signal, by said SCSI target, during said Packetized SCSI Protocol Data Out phase to indicate whether another data packet information unit is to be transmitted in said Packetized SCSI Protocol Data Out phase.

2. The method of claim 1 wherein said generating a signal further comprises:

driving a signal for a parity signal line of a SCSI bus.

3. The method of claim 2 wherein said driving a signal further comprises:

asserting a signal to indicate that said another data packet information unit is not to be transmitted in said Packetized SCSI Protocol Data Out phase.

4. The method of claim 1 wherein said generating a signal further comprises:

asserting a signal, for a line of a SCSI bus, to indicate that said another data packet information unit is not to be transmitted in said Packetized SCSI Protocol Data Out phase.

5. A method comprising:

entering a Packetized SCSI Protocol Data Out phase by a SCSI target; and

generating a signal on a parity bit line of a SCSI bus line, by said SCSI target during said SCSI Protocol Data Out phase, to indicate whether another data packet information unit is to be transmitted in said Packetized SCSI Protocol Data Out phase.

6. A method comprising:

receiving a plurality of data packet information units, one immediately after another, in said Packetized SCSI Protocol Data Out phase; and

determining whether to receive another data packet information unit in said Packetized SCSI Protocol Data Out phase following transmission of said plurality of data packet information units.

7. The method of claim 6 further comprising:

asserting a signal for a SCSI bus line, by said SCSI target during said Packetized SCSI Protocol Data Out phase, to indicate that said SCSI target will accept another data packet information unit in said Packetized SCSI Protocol Data Out phase.

8. A SCSI target device comprising:

a flow control module configured to perform a method comprising;

receiving a data packet information unit in a Packetized SCSI Protocol Data Out phase; and

generating a signal during said Packetized SCSI Protocol Data Out phase to indicate whether another data packet information unit is to be transmitted in said Packetized SCSI Protocol Data Out phase.

9. The SCSI target device of claim 8 wherein said generating a signal further comprises:

driving a signal for a parity signal line of a SCSI bus.

10. The SCSI target device of claim 9 wherein said driving a signal further comprises:

asserting a signal to indicate another data packet information unit is not to be transmitted in said Packetized SCSI Protocol Data Out phase.

11. The SCSI target device of claim 8 wherein said generating a signal further comprises:

asserting a signal, for a line of a SCSI bus, to indicate another data packet information unit is not to be transmitted in said Packetized SCSI Protocol Data Out phase.