Information handling system for transfer of command blocks to a local processing side without local processor intervention

• US 5,968,143 A
• Filed: 12/13/1995
• Issued: 10/19/1999
• Est. Priority Date: 12/13/1995
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: McNeill, Andrew Boyce Jr., Lee, Timothy Vincent, Chisholm, Douglas Roderick, Wachtel, Ed, Hoch, Gary
• Primary Examiner(s): Chan, Eddie P.
• Assistant Examiner(s): Nguyen, Hiep T.
• Application Number:
  US08/572,235
• Time in Patent Office: 1,406 Days
• Field of Search: 395/821, 395/824, 395/842, 395/843, 395/844, 395/845, 395/846, 395/847, 395/848, 395/309, 395/310
• US Class Current: 710/23
• CPC Class Codes: G06F 13/126 and has means for transferring I/O instructions and statuses between control unit and main processor

Abstract

An information handling system transfers command blocks between a host processing side having a host processing unit and a host memory and a local processing side having a local processing unit and a local memory. The command blocks are transferred from the host processing side to the local processing side by storing the host address of the command block in a local side register set. Upon storing the host address a transfer signal is given to a command block transfer controller to start a command block transfer without the local processor unit intervention.

Claims

1. An information handling system for transferring command blocks from a host processing side to a local processing side over an I/O expansion bus, comprising:

a host processing unit for processing command and data information on the host processing side;

a host memory accessible by the host processing unit including one or more memory portions for storing one or more command blocks created by the host processing unit to be transferred to the local processing side;

a local processing unit for processing command blocks transferred from the host processing side;

a local memory accessible by the local processing unit including one or more local memory portions for storing the command blocks transferred from the host processing side and a command address queue portion having a plurality of local command address images wherein each of the command address images stores a local command address information corresponding to a local memory portion; and

a command block transfer controller for controlling command block transfers including a command address register set accessible by the host processing unit and a command address queue register set programmable by the local processing unit before starting of any command block transfer for setting a predefined local memory address for the command address queue portion, the command address register set including address register for storing a host command address information corresponding to a host memory portion storing a command block to be transferred to the local processing side and a register for storing a command transfer start signal;

wherein the host processing unit writes the host command address information and concurrent therewith writes the command transfer start signal information into the signal register; and

wherein the command block transfer controller is responsive to the command start signal to retrieve the command block from the host memory without local processing unit intervention; and

wherein the command block transfer controller is responsive to said predefined local memory address for storing the command block in the local memory portion corresponding to the predefined local address.

2. The information handling system of claim 1, wherein a transferred command block includes a command portion and a command address portion appended thereto.

3. The information handling system of claim 2, wherein the command address portion includes a chain enable information indicating whether another command block is chained to the transferred command block.

4. The information handling system of claim 2, wherein the command address portion includes a host address of the command block chained to the transferred command block.

5. The information handling system of claim 4, wherein the command block transfer controller includes a detector to determined whether another command block is chained to the transferred command block by examining the chain enable information;

and wherein the command block transfer controller transfers the host memory address of the chained command block to the command address register set, and wherein the command block transfer controller is responsive to the host memory address so transferred for retrieving from a host memory portion a corresponding command block.

6. The information handling system of claim 1, wherein the local processing unit further storing, in said command address queue register set, a head pointer value pointing to a default command address image indicating where a subsequent local memory address information is to be stored and a tail pointer pointing to a default status queue image indicating from where a subsequent local command address information is to be retrieved.

7. The information handling system of claim 1, wherein the host processing unit writes a host command address information in the command address register set before start of any command block transfer.

8. The information handling system of claim 1, wherein the command address register set contains a command channel busy information indicating whether a command block transfer has completed.

9. The information handling of claim 8, wherein the host processing unit examines the channel busy information before starting a command block transfer.

10. The information handling system of claim 5, wherein the command block transfer controller further including a FIFO buffer coupled between a host memory access controller and a local memory access controller for receiving and temporarily storing data involved in a command block transfer.

11. The information handling system of claim 1, wherein the host command address information includes an address corresponding to a host memory portion and a size information indicating the length of a command block stored in the host memory portion.

12. The information handling system of claim 1, wherein the host processing side comprises a host system, and wherein the local processing side comprises a local interface controller.