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Ling adder

From Wikipedia, the free encyclopedia

In electronics, a Ling adder is a particularly fast binary adder designed using H. Ling's equations and generally implemented in BiCMOS. Samuel Naffziger of Hewlett-Packard presented an innovative 64 bit adder in 0.5 μm CMOS based on Ling's equations at ISSCC 1996. The Naffziger adder's delay was less than 1 nanosecond, or 7 FO4.[1]

Equations

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Ling adder, architecture Skllansky, radix-2, 4-bit

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In Borland Turbo Basic 1.1:

'--- Step 0 ------------ Warning ---------------------------------------
P00 = A0 OR  B0    '1dt, Initial only CLA & Ling Propagate (not in PPA)
G00 = A0 AND B0    '1dt, Initial CLA & Ling & PPA Generate
D00 = A0 XOR B0    '1dt, Only Ling Initial half bit generate (P0 in PPA)

P10 = A1 OR  B1    '1dt
G10 = A1 AND B1    '1dt
D10 = A1 XOR B1    '1dt

P20 = A2 OR  B2    '1dt
G20 = A2 AND B2    '1dt
D20 = A2 XOR B2    '1dt

P30 = A3 OR  B3    '1dt
G30 = A3 AND B3    '1dt
D30 = A3 XOR B3    '1dt

'--- Step 1, Ling Propagate and Generate ------
LG01 = G00          '1dt
LG11 = G10 OR  G00  '2dt

LP11 = P10          '1dt, Sklansky architecture
LG21 = G20          '1dt, Sklansky architecture

LP21 = P20 AND P10  '2dt
LG31 = G30 OR  G20  '2dt

'--- Step 2, Ling PseudoCarry (H) ---------------------------
H0 = LG01                     '1dt
H1 = LG11                     '2dt
H2 = LG21 OR (LP11 AND LG11)  '4dt TTL, Sklansky architecture
'    1dt      1dt      2dt
H3 = LG31 OR (LP21 AND LG11)  '4dt TTL
'    2dt      2dt      2dt
'--- Sum -----------------------------------------
S0 = (D00         )                           '1dt
S1 = (D10 AND 1-H0) OR ((D10 XOR P00) AND H0) '4dt TTL
S2 = (D20 AND 1-H1) OR ((D20 XOR P10) AND H1) '5dt TTL
S3 = (D30 AND 1-H2) OR ((D30 XOR P20) AND H2) '7dt TTL
S4 =                   ((        P30) AND H3) '5dt TTL, S4=C4=Cout 
[2]

Ling adder, architecture Kogge-Stone, radix-2, 4-bit

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'--- Step 0 ------------ Warning ---------------------------------------
P00 = A0 OR  B0    '1dt, Initial only CLA & Ling Propagate (not in PPA)
G00 = A0 AND B0    '1dt, Initial CLA & Ling & PPA Generate
D00 = A0 XOR B0    '1dt, Only Ling Initial half bit generate (P0 in PPA)

P10 = A1 OR  B1    '1dt
G10 = A1 AND B1    '1dt
D10 = A1 XOR B1    '1dt

P20 = A2 OR  B2    '1dt
G20 = A2 AND B2    '1dt
D20 = A2 XOR B2    '1dt

P30 = A3 OR  B3    '1dt
G30 = A3 AND B3    '1dt
D30 = A3 XOR B3    '1dt

'--- Step 1 ----------------------------
LG01 = G00          '1dt, Ling Generate

LP11 = P10 AND P00  '2dt, Ling Propagate, Kogge-Stone architecture
LG11 = G10 OR  G00  '2dt

LP21 = P20 AND P10  '2dt
LG21 = G20 OR  G10  '2dt, Kogge-Stone architecture

LG31 = G30 OR  G20  '2dt

'--- Step 2, Ling PsevdoCarry ----
H0 = LG01                     '1dt
H1 = LG11                     '2dt
H2 = LG21 OR (LP11 AND LG01)  '4dt TTL, Kogge-Stone architecture
'    2dt      2dt      1dt
H3 = LG31 OR (LP21 AND LG11)  '4dt TTL
'    2dt      2dt      2dt
'--- Sum -----------------------------------------
S0 = (D00         )                           '1dt
S1 = (D10 AND 1-H0) OR ((D10 XOR P00) AND H0) '4dt TTL
S2 = (D20 AND 1-H1) OR ((D20 XOR P10) AND H1) '5dt TTL
S3 = (D30 AND 1-H2) OR ((D30 XOR P20) AND H2) '7dt TTL
S4 =                  ((         P30) AND H3) '5dt TTL, S4=C4=Cout
[3]

References

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  1. ^ Naffziger, S. (8–10 February 1996). "A Sub-Nanosecond 0.5um 64b Adder Design" (PDF). Digest of Technical Papers, 1996 IEEE International Solid-State Circuits Conference. San Francisco. pp. 362–363. Archived from the original (PDF) on 10 April 2006.
  2. ^ http://andserkul.narod.ru/R2LSK4.bas [bare URL]
  3. ^ http://andserkul.narod.ru/R2LKS4.bas [bare URL]
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  1. H. Ling, "High Speed Binary Parallel Adder", IEEE Transactions on Electronic Computers, EC-15, p. 799-809, October, 1966.
  2. H. Ling, "High-Speed Binary Adder", IBM J. Res. Dev., vol.25, p. 156-66, 1981.
  3. R. W. Doran, "Variants on an Improved Carry Look-Ahead Adder", IEEE Transactions on Computers, Vol.37, No.9, September 1988.
  4. N. T. Quach, M. J. Flynn, "High-Speed Addition in CMOS", IEEE Transactions on Computers, Vol.41, No.12, December, 1992.
  5. S. Naffziger, "High Speed Addition Using Ling's Equations and Dynamic CMOS Logic", U.S. Patent No. 5,719,803, Issued: February 17, 1998.
  6. G. Dimitrakopoulos, D. Nikolos, "High-Speed Parallel-Prefix VLSI Ling Adders", IEEE Transaction on Computers, Vol.54, No.2, February, 2005.