Library of Arithmetic Units

SystemVerilog Edition!

Based on the VHDL library written by Reto Zimmermann.

The library contains various arithmetic operations with multiple architectural choices for different speed requirements. All operations are parametrized in width and performance grade.

Disclaimer

This project is still under active development; some parts may not yet be fully functional, and existing interfaces, toolflows, and conventions may be broken without prior notice. We target a stable release as soon as possible.

License

All code checked into this repository is licensed under the permissive Solderpad Hardware License 0.51 (See LICENSE).

Available Operations

Adders

Name	Description	unsigned	signed	slow	medium	fast
Add	Adder	X	X	S	M	F
AddC	Adder with carry-in, carry-out	X		S	M	F
AddCfast	Adder with fast carry-in, carry-out	X		S	M	F
AddV	Adder with carry-in, 2’s compl. overflow flag		X	S	M	F
AddMod2Nm1	Adder modulo 2^n - 1 (double zero representation)	X		S	M	F
AddMod2Nm1s0	Adder modulo 2^n - 1 (single zero representation)	X		S	M	F
AddMod2Np1	Adder modulo 2^n + 1	X		S	M	F
AddCsv	Carry-save adder (3 operands)	X	X			F
AddMop	Multi-operand adder	X	X	S	M	F
AddMopCsv	Carry-save multi-operand adder	X	X	S		F

Subtractors, Complementers

Name	Description	unsigned	signed	slow	medium	fast
Sub	Subtractor	X	X	S	M	F
SubC	Subtractor with carry-in, carry-out	X		S	M	F
SubCZ	Subtractor with carry-in, carry-out, zero flag	X		S	M	F
SubV	Subtractor with carry-in, 2’s compl. overflow flag		X	S	M	F
SubVZ	Subtractor with carry-in, 2’s compl. ovl. & zero flag		X	S	M	F
Neg	2’s complementer (negation)		X	S	M	F
NegC	2’s complementer, conditional		X	S	M	F
AbsVal	Absolute value for 2’s complement numbers		X	S	M	F

Adder-Subtractors

Name	Description	unsigned	signed	slow	medium	fast
AddSub	Adder-subtractor	X	X	S	M	F
AddSubC	Adder-subtractor with carry-in, carry-out	X		S	M	F
AddSubV	Adder-subtractor with carry-in, 2’s compl. ovl. flag		X	S	M	F

Incrementers, Decrementers

Name	Description	unsigned	signed	slow	medium	fast
Inc	Incrementer	X	X	S	M	F
IncC	Incrementer with carry-in, carry-out	X		S	M	F
Dec	Decrementer	X	X	S	M	F
DecC	Decrementer with carry-in, carry-out	X		S	M	F
IncDec	Incrementer-decrementer	X	X	S	M	F
IncDecC	Incrementer-decrementer with carry-in, carry-out	X		S	M	F

Comparators

Name	Description	unsigned	signed	slow	medium	fast
CmpEQ	Equality comparator	X	X			F
CmpGE	Magnitude comparator	X		S	M	F
CmpEQGE	Equality and magnitude comparator	X	X	S	M	F

Multipliers

Name	Description	unsigned	signed	slow	medium	fast
MulSgn	Signed multiplier		X	S	M	F
MulUns	Unsigned multiplier	X		S	M	F
MulAddSgn	Signed multiplier-adder		X	S	M	F
MulAddUns	Unsigned multiplier-adder	X		S	M	F
AddMulSgn	Signed adder-multiplier		X	S	M	F
AddMulUns	Unsigned adder-multiplier	X		S	M	F
MulCsvSgn	Signed carry-save multiplier		X	S		F
MulCsvUns	Unsigned carry-save multiplier	X		S		F
SqrSgn	Signed squarer		X	S	M	F
SqrUns	Unsigned squarer	X		S	M	F

Dividers, Square-Root Extractors

Name	Description	unsigned	signed	slow	medium	fast
DivArrSgn	Signed array divider		X	S
DivArrUns	Unsigned array divider	X		S
SqrtArrUns	Unsigned array square-root extractor	X		S

Detectors

Name	Description	unsigned	signed	slow	medium	fast
AllZeroDet	All-zeroes detector					F
AllOneDet	All-ones detector					F
SumZeroDet	Unsigned array square-root extractor	X	X			F
LeadZeroDet	Leading-zeroes detector (LZD)	X		S	M	F
LeadOneDet	Leading-ones detector (LOD)	X		S	M	F
LeadSignDet	Leading-signs detector (LSD)		X	S	M	F
Log2	Integer logarithm (base 2)	X		S	M	F

Encoders, Decoders, Gray

Name	Description	slow	medium	fast
Decode	Decoder			F
Encode	Encoder			F
Bin2Gray	Binary-to-Gray converter			F
Gray2Bin	Gray-to-binary converter	S	M	F
IncGray	Gray incrementer	S	M	F
IncGrayC	Gray incrementer with carry-in	S	M	F

Miscellaneous

Name	Description	slow	medium	fast
Cnt	(m,k)-counter	S		F
Cpr	(m,2)-compressor	S		F
RedAnd	Reduce-AND			F
RedOr	Reduce-OR			F
RedXor	Reduce-XOR			F
PrefixAnd	Prefix-AND	S	M	F
PrefixOr	Prefix-OR	S	M	F
PrefixAndOr	Prefix-AND-OR	S	M	F
PrefixXor	Prefix-XOR	S	M	F