Chapter 2 Function Block
4-Bit Carry Look Ahead Adder
Chapter 2 Function Block
Switching speed
Function
Block
type
Input
Output
Path
→
t LD0 (ns)
t 1
Standard type
Block type
IN
A0
OUT
MIN.
TYP. MAX.
MIN.
0.011
0.010
0.011
0.010
0.011
0.010
0.011
0.010
0.011
0.010
0.011
0.010
0.011
0.010
0.011
0.010
0.015
0.011
0.011
0.026
0.011
0.010
0.011
0.010
0.011
0.010
0.011
0.010
0.011
0.010
0.011
0.010
0.011
0.010
0.011
0.010
0.011
0.010
0.015
0.011
0.011
0.026
0.011
0.010
0.011
0.010
0.011
0.010
0.011
0.010
0.011
0.010
0.011
0.010
0.011
0.010
TYP. MAX. Symbol Fanin Symbol Fanout
Normal
High speed
(HH) 0.461
(HL) 0.513
(LH) 0.509
0.890
0.917
0.933
0.951
0.940
0.807
0.791
0.923
1.163
1.200
1.154
1.195
1.348
1.386
1.350
1.389
1.454
1.409
0.507
0.535
1.348
1.350
0.891
0.937
0.960
0.940
0.943
0.827
0.786
0.923
1.183
1.220
1.150
1.190
1.368
1.406
1.345
1.385
1.474
1.404
0.508
0.535
1.367
1.345
0.942
0.959
0.968
1.017
0.895
0.932
0.821
0.861
1.195
1.232
1.110
1.150
1.705
1.755
1.773
1.815
1.814
1.528
1.513
1.732
2.308
2.337
2.201
2.268
2.670
2.694
2.611
2.672
2.860
2.698
0.925
1.068
2.629
2.569
1.705
1.794
1.839
1.812
1.815
1.568
1.571
1.732
2.348
2.377
2.259
2.326
2.711
2.734
2.669
2.730
2.900
2.756
0.927
1.068
2.669
2.627
1.792
1.820
1.816
1.936
1.879
1.911
1.614
1.681
2.459
2.483
2.130
2.194
0.015
0.013
0.015
0.013
0.015
0.013
0.015
0.013
0.015
0.013
0.015
0.013
0.015
0.013
0.015
0.013
0.020
0.015
0.015
0.037
0.016
0.013
0.015
0.013
0.015
0.013
0.015
0.013
0.015
0.013
0.015
0.013
0.015
0.013
0.015
0.013
0.015
0.013
0.020
0.015
0.015
0.037
0.016
0.013
0.015
0.013
0.015
0.013
0.015
0.013
0.015
0.013
0.015
0.013
0.015
0.013
0.022
0.018
0.022
0.018
0.021
0.018
0.022
0.018
0.021
0.018
0.022
0.018
0.021
0.018
0.022
0.018
0.030
0.021
0.022
0.062
0.023
0.017
0.022
0.018
0.022
0.018
0.021
0.017
0.022
0.018
0.021
0.018
0.022
0.018
0.021
0.018
0.022
0.018
0.030
0.021
0.022
0.062
0.023
0.017
0.022
0.018
0.022
0.018
0.021
0.018
0.022
0.018
0.021
0.018
0.022
0.018
A0
B0
A1
B1
A2
B2
A3
B3
CINB
2.9
3.0
2.9
3.1
2.9
3.1
2.8
3.0
2.1
F0
F1
F2
F3
COUTB
X
31
31
31
31
25
8
F527
→
→
→
→
F0
F1
F2
F3
Drivability
Name cells
Name cells
Low Power
x1
(LL)
0.498
F527
69
(HH) 0.467
(HL) 0.486
(LH) 0.488
A0
A0
A0
x2
x4
Y
28
(LL)
0.489
(HH) 0.693
(HL) 0.717
(LH) 0.708
Logic Diagram
B3 H08
A3 H07
B2 H06
A2 H05
B1 H04
A1 H03
B0 H02
A0 H01
CINB H09
(LL)
0.725
(HH) 0.800
(HL) 0.826
(LH) 0.817
N07
N06
N05 COUTB
N04 S3
Y
X
(LL)
0.837
(HL) 0.877
(LH) 0.855
(HH) 0.311
A0
A0
A0
B0
→
→
→
→
COUTB
N03 S2
X
N02 S1
N01 S0
(LL)
(HH) 0.811
(LL) 0.821
0.314
Y
(HH) 0.471
(HL) 0.519
(LH) 0.484
F0
(LL)
0.504
(HH) 0.482
(HL) 0.502
(LH) 0.472
B0
B0
B0
→
→
→
F1
F2
F3
Truth Table
(LL)
0.488
(HH) 0.707
(HL) 0.733
(LH) 0.692
A0
B0
A1
B1
A2
B2
A3
B3
*1
S0
S1
S2
S3
*2
X
Y
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
0
0
0
1
1
1
1
1
0
0
1
0
1
1
0
0
1
0
1
0
0
1
1
0
1
0
1
0
1
1
1
0
1
0
1
0
1
1
1
1
1
0
0
1
1
1
0
0
0
0
1
0
0
0
1
0
0
1
1
0
0
1
1
(LL)
0.710
(HH) 0.816
(HL) 0.841
(LH) 0.801
(LL)
0.822
(HL) 0.893
(LH) 0.839
(HH) 0.311
B0
B0
B0
A1
→
→
→
→
COUTB
(n=0,1,2,3) , *1:CinB , *2:CoutB
Sn=(An+Bn+CinB)
X
(LL)
(HH) 0.827
(LL) 0.805
0.315
X=(A0¥B0)+(A1¥B1)+(A2¥B2)+(A3¥B3)
Y=1:(An+Bn)>=1111
Y
Y=0:(An+Bn)<1111
(HH) 0.488
(HL) 0.536
(LH) 0.546
F1
(LL)
0.514
(HH) 0.516
(HL) 0.542
(LH) 0.496
A1
A1
→
→
F2
F3
(LL)
0.513
(HH) 0.698
(HL) 0.724
(LH) 0.676
(LL)
0.693
Block Library A13872EJ5V0BL
2 - 194
Block Library A13872EJ5V0BL
2 - 195
ETC [ ETC ]
