Digital multiply-accumulate circuit that can operate on both integer and floating point numbers simultaneously
US6205462A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1999 |
| Grant date | Mar 20, 2001 |
| Priority date | — |
| Expiry date | Oct 6, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2207/3824
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Disclosed is a Multiply-Accumulate circuit that includes an exponent adder circuit, a mantissa multiplier circuit, a shifter, a full adder, and an accumulator. The product adder circuit receives two operands in a special combined data format which prescribes a mantissa and an exponent for both integer and floating point operands. The exponent adder circuit adds the exponents of the two operands. But if before the addition the exponent adder circuit detects an integer as an operand, it replaces the exponent of the integer by a substitute value in that addition. This substitute value is related to the number of bits of the mantissa of the integer. The mantissa multiplier circuit multiplies the two mantissas of the two operands. The shifter shifts the resultant product of multiplication into a pre-defined fixed point format according to the resultant sum of the addition generated by the exponent adder circuit. The full adder adds this shifted product to the current content of the accumulator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.