Centralized control SIMD processor having different priority levels set for each data transfer request type and successively repeating the servicing of data transfer request in a predetermined order

• US 5,522,080 A
• Filed: 07/20/1994
• Issued: 05/28/1996
• Est. Priority Date: 10/24/1991
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Harney, Kevin
• Primary Examiner(s): AN, MENG AI T
• Application Number:
  US08/277,772
• Time in Patent Office: 678 Days
• Field of Search: 395/800, 395/727, 395/729, 395/732, 395/860, 395/299, 340/825.5, 340/825.51, 340/172.5, 370/85.6, 364/DIG. 1, 364/DIG. 2
• US Class Current: 710/220
• CPC Class Codes: G06F 9/30072 to perform conditional operations, e.g. using predicates or guards
• CPC Class Codes: G06F 9/30149 of variable length instructions
• CPC Class Codes: G06F 9/3802 Instruction prefetching
• CPC Class Codes: G06F 9/3863 using multiple copies of the architectural state, e.g. shadow registers
• CPC Class Codes: G06F 9/3885 using a plurality of independent parallel functional units

Abstract

Features which support conditional execution and sequencing are employed in concert with a centralized-control, single-instruction, multiple data integrated video signal processor, thus adapting efficiently to the high degree of parallelism inherent in this type of video signal processing systems. A three-level prioritization scheme is used to handle the input/output data stream to improve the throughput of the processor, including provisions for distinguishing between same-priority events occurring at different times, and ensuring that in such cases the requested operations occur in the same temporal order as the respective requests.

Claims

1. A single-instruction multiple-data processing system for implementing prioritized input/output data handling, the system comprising:

(a) a plurality of system components each requesting at least one data transfer via an input/output data stream of the system to provide a plurality of data transfer requests, said each data transfer having a data transfer type of a plurality of data transfer types, and each of said data transfer types having an associated bandwidth requirement;

(b) means for setting a first, second, or third priority level for each data transfer type of the plurality of data transfer types in accordance with the bandwidth requirement of each data transfer type, wherein the first priority level data transfers are data transfers having relatively low bandwidth requirements, the second priority level data transfers are data transfers having bursty bandwidth requirements, and the third priority level data transfers are data transfers having relatively high bandwidth requirements;

(c) means for servicing the plurality of data transfer requests by providing for transfer of data via the input/output data stream for selected data transfer requests of the plurality of data transfer requests in the order;

first priority level, second priority level, first priority level, third priority level; and

(d) means for successively repeating the servicing of servicing means (c) for unsatisfied data transfer requests of the plurality of data transfer requests.

2. The system of claim 1, wherein:

the setting means further comprises means for setting a relative local priority level for each data transfer type within a given priority level; and

the servicing means further comprises means for servicing data transfer requests of the same priority level in accordance with the relative local priority levels of the data transfer requests of the same priority level.

3. A system for implementing prioritized input/output data handling, comprising:

(a) a plurality of system components each requesting at least one data transfer via an input/output data stream of the system to provide a plurality of pending data transfer requests, said each data transfer having a data transfer type of a plurality of data transfer types, each of said data transfer types having an associated bandwidth requirement;

(b) means for setting a first, second, or third priority level for each of said data transfer types of the plurality of data transfer types in accordance with the bandwidth requirement of each data transfer type, wherein the first priority level data transfers are data transfers having relatively bandwidth requirements, the second priority level data transfers are data transfers having bursty bandwidth requirements, and the third priority level data transfers are data transfers having relatively high bandwidth requirements;

(c) means for polling all pending first priority data transfer requests and servicing a selected first priority data transfer request of the pending first priority data transfer requests, wherein servicing a data transfer request comprises providing for transfer of data via the input/output data stream;

(d) means for polling all pending second priority data transfer requests and servicing a selected second priority data transfer request of the pending second priority data transfer requests;

(e) means for polling all pending first priority data transfer requests and servicing a second selected first priority data transfer request of the pending first priority data transfer requests;

(f) means for polling all pending third priority data transfer requests and servicing a selected third priority data transfer request of the pending second priority data transfer requests; and

(g) means for successively repeating the polling and servicing of means (c)-(f).

4. The system of claim 3, wherein:

the setting means further comprises means for setting a relative local priority level for each data transfer type within a given priority level; and

pending data transfer requests are selected for servicing by means for polling in (c)-(f) in accordance with the relative local priority levels of the data transfer requests of the same priority level.

5. A method for implementing prioritized input/output data handling in a single-instruction multiple-data processing system having a plurality of system components each requesting at least one clam transfer via an input/output data stream of the system to provide a plurality of data transfer requests, said each data transfer having a data transfer type of a plurality of data transfer types, and each of said data transfer types having an associated bandwidth requirement, the method comprising the steps of:

(a) setting a first, second, or third priority level for each of said data transfer types of the plurality of data transfer types in accordance with the bandwidth requirement of each data transfer type, wherein the first priority level data transfers are data transfer having relatively low bandwidth requirements, the second priority level data transfers are data transfers having bursty bandwidth requirements, third priority level data transfers are data transfers having relatively high bandwidth requirements;

(b) servicing the plurality of data transfer requests by providing for transfer of data via the input/output data stream for selected data transfer requests of the plurality of data transfer requests in the order;

first priority level, second priority level, first priority level, third priority level; and

(c) successively repeating the servicing of step (b) for unsatisfied data transfer requests of the plurality of data transfer requests.

6. The method of claim 5, wherein:

step (a) further comprises the step of setting a relative local priority level for each data transfer type within a given priority level; and

step (b) further comprises the step of servicing data transfer requests of a same priority level in accordance with the relative local priority levels of the data transfer requests of the same priority level.