Arithmetic engine with dual multiplier accumulator devices

• US 5,522,085 A
• Filed: 02/24/1995
• Issued: 05/28/1996
• Est. Priority Date: 12/20/1993
• Status: Expired due to Fees

• Current Assignee: General Dynamics C4 Systems Incorporated (General Dynamics Corporation)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Harrison, Calvin W., Gilfeather, Susan L., Gehman, John B. Jr.
• Primary Examiner(s): Bowler, Alyssa H.
• Assistant Examiner(s): Davis, Jr., Walter D.
• Application Number:
  US08/394,054
• Time in Patent Office: 459 Days
• Field of Search: 395/800, 364/DIG. 1, 364/726, 364/754, 364/724, 364/744, 364/736, 382/41
• US Class Current: 712/32
• CPC Class Codes: G06F 17/10 Complex mathematical operations function generation by table look-up G06F1/03; evaluation of elementary functions by calculation G06F7/544

Abstract

An arithmetic engine includes a first dual multiplier accumulator (MAC) for receiving input data and for producing first dual MAC output data. A second dual MAC is coupled in parallel to the first dual MAC. The second dual MAC receives the input data and produces second dual MAC output data. An adder array is coupled to both the first dual MAC and to the second dual MAC. The adder array receives the input data, the first dual MAC output data, and the second dual MAC output data and produces arithmetic engine output data. Each dual MAC comprises a multiplier cross point switch, multiplier registers, a register selector, and parallel multipliers. Each adder array comprises a cross point switch, adder registers, a register selector, adder, and condition code determiner.

Claims

1. An arithmetic engine comprising:

a first dual multiplier accumulator (MAC) for receiving input data at a first dual MAC first input and for producing first dual MAC output data at a first dual MAC output, wherein the first dual MAC comprises;

a dual multiplier for receiving a plurality of sources and for producing first and second parallel multiplier outputs, the dual multiplier including a multiplier cross point switch for receiving the plurality of sources and for producing selected sources at a plurality of multiplier cross point switch outputs, wherein the dual multiplier comprises;

a plurality of multiplier registers coupled to the multiplier cross point switch outputs, the plurality of multiplier registers for storing the selected sources as multiplier register values;

a register selector coupled to the plurality of multiplier registers, the register selector for choosing selected multiplier operands from the multiplier register values; and

first and second parallel multipliers coupled to the register selector, the first and the second parallel multipliers for receiving pairs of selected multiplier operands and multiplying the pairs of selected multiplier operands to produce the first and the second parallel multiplier outputs, respectively;

an accumulator coupled to the dual multiplier, the accumulator for receiving the first and second parallel multiplier outputs, selecting particular first and second parallel multiplier outputs in a condition code determiner, and for producing the first dual MAC output data therefrom, the accumulator comprising;

a plurality of adder registers for storing the first and the second parallel multiplier outputs and a plurality of accumulator registers for storing a first and a second accumulator output;

an accumulator cross point switch coupled to the plurality of adder registers and the plurality of accumulator registers, the accumulator cross point switch for producing selected accumulator register and adder register values from the first and the second parallel multiplier outputs and the first and the second accumulator outputs;

first and second parallel MAC adders coupled to the accumulator cross point switch, the first and the second parallel MAC adders for receiving pairs of selected accumulator register and adder register values and adding the pairs of selected accumulator register and adder register values to produce the first and the second accumulator adder outputs; and

a MAC output selector coupled to the first and to the second parallel MAC adders and to the first and to the second parallel multipliers, the MAC output selector for receiving the first and the second accumulator outputs and the first and the second parallel multiplier outputs and for producing the first dual MAC output data; and

a first dual MAC second input;

a second dual MAC coupled in parallel to the first dual MAC, the second dual MAC for receiving the input data at a second dual MAC first input and for producing second dual MAC output data at a second dual MAC output, wherein the second dual MAC comprises a second dual MAC second input; and

an adder array coupled to both the first dual MAC and to the second dual MAC, the adder array for receiving the input data, the first dual MAC output data, and the second dual MAC output data and for producing arithmetic engine output data at an adder array output, wherein the first dual MAC second input is coupled to the adder array output, the first dual MAC output is coupled to the adder array output, the second dual MAC second input is coupled to the adder array output, and the second dual MAC output is coupled to the adder array output.

2. An arithmetic engine as claimed in claim 1, wherein the second parallel MAC adder produces a condition code input to the condition code determiner, and the condition code determiner produces a condition code output to the MAC output selector.

3. An arithmetic engine as claimed in claim 1, wherein the adder array comprises:

a first adder pair for receiving the input data, the first dual MAC output data, the second dual MAC output data and first, second, and third adder pair outputs, and for producing first adder pair outputs;

a second adder pair coupled to the first adder pair, the second adder pair for receiving the input data, the first dual MAC output data, the second dual MAC output data, and the first, the second, and the third adder pair outputs and for producing second adder pair outputs; and

a third adder pair coupled to the second adder pair, the third adder pair for receiving the input data, the first dual MAC output data, the second dual MAC output data, and the first, the second, and the third adder pair outputs and for producing the arithmetic engine output data at the adder array output.

4. An arithmetic engine as claimed in claim 3, wherein each adder of the first adder pair comprises:

a first adder cross point switch for producing first selected values of the input data, the first MAC output data, the second MAC output data and the first, the second, and the third adder pair outputs;

first adder registers coupled to the first adder cross point switch, the first registers for storing the first selected values;

a first adder register selector coupled to the first adder registers, the first adder register selector for receiving and choosing first operands and for producing a first adder sum output from the first selected values;

a first adder coupled to the first adder register selector, the first adder for receiving and adding the first operands and for producing one of the first adder pair outputs; and

a first condition code determiner for receiving a first adder condition code input and for providing a first condition code to the first adder register selector.

5. An arithmetic engine as claimed in claim 3, wherein each adder of the second adder pair comprises:

a second adder cross point switch for producing second selected values of the input data, the first dual MAC output data, the second dual MAC output data, and the first, the second, and the third adder pair outputs;

second adder registers coupled to the second adder cross point switch, the second adder registers for storing the second selected values;

a second adder register selector coupled to the second adder registers, the second adder register/selector for receiving and choosing second operands from the second selected values;

a second adder coupled to the second adder register selector, the second adder for receiving and adding the second operands and for producing one of the second adder pair outputs; and

a second condition code determiner for receiving a second adder condition code input and for providing a second condition code to the second adder register selector.

6. An arithmetic engine as claimed in claim 3, wherein each adder of the third adder pair comprises:

a third adder cross point switch for producing third selected values of the input data, the first dual MAC output data, the second dual MAC output data, and the first, the second and the third adder pair outputs;

third adder registers coupled to the third adder cross point switch, the third adder registers for storing the third selected values;

a third adder register selector coupled to the third adder registers, the third adder register selector for receiving and choosing third operands from the third selected values;

a third adder coupled to the third adder register selector, the third adder for receiving and adding the third operands and for producing the arithmetic engine output data; and

a third condition code determiner for receiving a third condition code input and for providing a third condition code to the third adder register selector.

7. A complex arithmetic processor including an arithmetic engine comprising:

a first dual multiplier accumulator (MAC) for receiving input data at a first dual MAC first input and for producing first dual MAC output data at a first dual MAC output, wherein the first dual MAC comprises;

a dual multiplier for receiving a plurality of sources and for producing first and second parallel multiplier outputs, the dual multiplier including a multiplier cross point switch for receiving the plurality of sources and for producing selected sources at a plurality of multiplier cross point switch outputs, wherein the dual multiplier comprises;

a plurality of multiplier registers coupled to the multiplier cross point switch outputs, the plurality of multiplier registers for storing the selected sources as multiplier register values;

a register selector coupled to the plurality of multiplier registers, the register selector for choosing selected multiplier operands from the multiplier register values; and

first and second parallel multipliers coupled to the register selector, the first and the second parallel multipliers for receiving pairs of selected multiplier operands and multiplying the pairs of selected multiplier operands to produce the first and the second parallel multiplier outputs, respectively;

an accumulator coupled to the dual multiplier, the accumulator for receiving the first and second parallel multiplier outputs, selecting particular first and second parallel multiplier outputs in a condition code determiner, and for producing the first dual MAC output data therefrom, wherein the accumulator comprises;

a plurality of adder registers for storing the first and the second parallel multiplier outputs and a plurality of accumulator registers for storing a first and a second accumulator output;

an accumulator cross point switch coupled to the plurality of adder registers and the plurality of accumulator registers, the accumulator cross point switch for producing selected accumulator register and adder register values from the first and the second parallel multiplier outputs and the first and the second accumulator outputs;

first and second parallel MAC adders coupled to the accumulator cross point switch, the first and the second parallel MAC adders for receiving pairs of selected accumulator register and adder register values and adding the pairs of selected accumulator register and adder register values to produce the first and the second accumulator adder outputs; and

a MAC output selector coupled to the first and to the second parallel MAC adders and to the first and to the second parallel multipliers, the MAC output selector for receiving the first and the second accumulator outputs and the first and the second parallel multiplier outputs and for producing the first dual MAC output data;

a first dual MAC second input;

a second dual MAC coupled in parallel to the first dual MAC, the second dual MAC for receiving the input data at a second dual MAC first input and for producing second dual MAC output data at a second dual MAC output, wherein the second dual MAC comprises a second dual MAC second input; and

an adder array coupled to both the first dual MAC and to the second dual MAC, the adder array for receiving the input data, the first dual MAC output data, and the second dual MAC output data and for producing arithmetic engine output data at an adder array output, wherein the first dual MAC second input is coupled to the adder array output, the first dual MAC output is coupled to the adder array output, the second dual MAC second input is coupled to the adder array output, and the second dual MAC output is coupled to the adder array output.

8. A complex arithmetic processor as claimed in claim 7, wherein the second parallel MAC adder produces a condition code input to the condition code determiner, and the condition code determiner produces a condition code output to the MAC output selector.

9. A complex arithmetic processor as claimed in claim 7, wherein the adder array comprises:

a first adder pair for receiving the input data, the first dual MAC output data, the second dual MAC output data and first, second, and third adder pair outputs, and for producing first adder pair outputs;

a second adder pair coupled to the first adder pair, the second adder pair for receiving the input data, the first dual MAC output data, the second dual MAC output data, and the first, the second, and the third adder pair outputs and for producing second adder pair outputs; and

a third adder pair coupled to the second adder pair, the third adder pair for receiving the input data, the first dual MAC output data, the second dual MAC output data, and the first, the second, and the third adder pair outputs and for producing the arithmetic engine output data at the adder array output.

10. A complex arithmetic processor as claimed in claim 9, wherein each adder of the first adder pair comprises:

a first adder cross point switch for producing first selected values of the input data, the first MAC output data, the second MAC output data and the first, the second, and the third adder pair outputs;

first adder registers coupled to the first adder cross point switch, the first registers for storing the first selected values;

a first adder register selector coupled to the first adder registers, the first adder register selector for receiving and choosing first operands and for producing a first adder sum output from the first selected values;

a first adder coupled to the first adder register selector, the first adder for receiving and adding the first operands and for producing one of the first adder pair outputs; and

a first condition code determiner for receiving a first adder condition code input and for providing a first condition code to the first adder register selector.

11. A complex arithmetic processor as claimed in claim 9, wherein each adder of the second adder pair comprises:

a second adder cross point switch for producing second selected values of the input data, the first dual MAC output data, the second dual MAC output data, and the first, the second, and the third adder pair outputs;

second adder registers coupled to the second adder cross point switch, the second adder registers for storing the second selected values;

a second adder register selector coupled to the second adder registers, the second adder register selector for receiving and choosing second operands from the second selected values;

a second adder coupled to the second adder register selector, the second adder for receiving and adding the second operands and for producing one of the second adder pair outputs; and

a second condition code determiner for receiving a second adder condition code input and for providing a second condition code to the second adder register selector.

12. A complex arithmetic processor as claimed in claim 9, wherein each adder of the third adder pair comprises:

a third adder cross point switch for producing third selected values of the input data, the first dual MAC output data, the second dual MAC output data, and the first, the second and the third adder pair outputs;

third adder registers coupled to the third adder cross point switch, the third adder registers for storing the third selected values;

a third adder register selector coupled to the third adder registers, the third adder register selector for receiving and choosing third operands from the third selected values;

a third adder coupled to the third adder register selector, the third adder for receiving and adding the third operands and for producing the arithmetic engine output data; and

a third condition code determiner for receiving a third condition code input and for providing a third condition code to the third adder register selector.