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* ADDER - 4 BIT ALL-NAND-GATE BINARY ADDER
*** SUBCIRCUIT DEFINITIONS
.SUBCKT NAND in1 in2 out VDD
* NODES: INPUT(2), OUTPUT, VCC
M1 out in2 Vdd Vdd p1 W=3u L=1u
M2 net.1 in2 0 0 n1 W=3u L=2u
M3 out in1 Vdd Vdd p1 W=3u L=1u
M4 out in1 net.1 0 n1 W=3u L=2u
.ENDS NAND
.SUBCKT ONEBIT 1 2 3 4 5 6
* NODES: INPUT(2), CARRY-IN, OUTPUT, CARRY-OUT, VCC
X1 1 2 7 6 NAND
X2 1 7 8 6 NAND
X3 2 7 9 6 NAND
X4 8 9 10 6 NAND
X5 3 10 11 6 NAND
X6 3 11 12 6 NAND
X7 10 11 13 6 NAND
X8 12 13 4 6 NAND
X9 11 7 5 6 NAND
.ENDS ONEBIT
.SUBCKT TWOBIT 1 2 3 4 5 6 7 8 9
* NODES: INPUT - BIT0(2) / BIT1(2), OUTPUT - BIT0 / BIT1,
* CARRY-IN, CARRY-OUT, VCC
X1 1 2 7 5 10 9 ONEBIT
X2 3 4 10 6 8 9 ONEBIT
.ENDS TWOBIT
.SUBCKT FOURBIT 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
* NODES: INPUT - BIT0(2) / BIT1(2) / BIT2(2) / BIT3(2),
* OUTPUT - BIT0 / BIT1 / BIT2 / BIT3, CARRY-IN, CARRY-OUT, VCC
X1 1 2 3 4 9 10 13 16 15 TWOBIT
X2 5 6 7 8 11 12 16 14 15 TWOBIT
.ENDS FOURBIT
*** DEFINE NOMINAL CIRCUIT
VCC 99 0 DC 3.3V
VIN1A 1 0 PULSE(0 3 0 10NS 10NS 10NS 50NS)
VIN1B 2 0 PULSE(0 3 0 10NS 10NS 20NS 100NS)
VIN2A 3 0 PULSE(0 3 0 10NS 10NS 40NS 200NS)
VIN2B 4 0 PULSE(0 3 0 10NS 10NS 80NS 400NS)
VIN3A 5 0 PULSE(0 3 0 10NS 10NS 160NS 800NS)
VIN3B 6 0 PULSE(0 3 0 10NS 10NS 320NS 1600NS)
VIN4A 7 0 PULSE(0 3 0 10NS 10NS 640NS 3200NS)
VIN4B 8 0 PULSE(0 3 0 10NS 10NS 1280NS 6400NS)
X1 1 2 3 4 5 6 7 8 9 10 11 12 0 13 99 FOURBIT
*RBIT0 9 0 100K
*RBIT1 10 0 100K
*RBIT2 11 0 100K
*RBIT3 12 0 100K
*RCOUT 13 0 100K
.TRAN 1NS 1000NS
.model n1 nmos level=8 version=3.3.0
.model p1 pmos level=8 version=3.3.0
.END
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