library (ExamBus) {
date : "May 14, 2002";
 revision : 2002.05;
 bus_naming_style :"%s[%d]";/* Optional; this is the
 default */
type (bus4) {
base_type : array;/* Required */
data_type : bit;/* Required if base_type is array */
bit_width : 4;/* Optional; default is 1 */
bit_from : 0;/* Optional MSB; defaults to 0 */
bit_to : 3;/* Optional LSB; defaults to 0 */
downto : false;/* Optional; defaults to false */
}
cell (bused_cell) {
area : 10;
bus (A) {
bus_type : bus4;
direction : input;
capacitance : 3;
pin (A[0:2]) {
capacitance : 2;
}
pin (A[3]) {
 capacitance : 2.5;
}
}
bus (B) {
bus_type : bus4;
capacitance : 2;
}
pin (E) {
direction : input ;
capacitance : 2 ;
}
bus(X) {
bus_type : bus4;
direction : output;
capacitance : 1;
pin (X[0:3]) {
function : "A & B’";
timing() {
related_pin : "A B";
/* A[0] and B[0] are related to X[0],
A[1] and B[1] are related to X[1], etc. */
}
}
}
bus (Y) {
bus_type : bus4;
direction : output;
capacitance : 1;
pin (Y[0:3]) {
function : "B";
three_state : "!E";
timing () {
related_pin : "A[0:3] B E";
}
internal_power() {
when: "E" ;
related_pin : B ;
power() {
}
}
internal_power() {
related_pin : B ;
power() {
}
}
}
}
bus (Z) {
bus_type : bus4;
direction : output;
pin (Z[0:1]) {
function : "!A[0:1]";
timing () {
related_pin : "A[0:1]";
}
internal_power() {
related_pin  : "A[0:1]";
power() {
}
}
}
pin (Z[2]) {
function : "A[2]";
timing () {
related_pin : "A[2]";
}
internal_power() {
related_pin : "A[0:1]";
power() {
}
}
}
pin (Z[3]) {
function : "!A[3]";
timing () {
related_pin : "A[3]";
}
internal_power() {
related_pin : "A[0:1]";
power() {
}
}
}
}
pin_opposite("Y[0:1]","Z[0:1]");
/* Y[0] is opposite to Z[0], etc. */
pin_equal("Y[2:3] Z[2:3]");
 /* Y[2], Y[3], Z[2], and Z[3] are equal */
cell (bused_cell2) {
area : 20;
bus (A) {
bus_type : bus41;
direction : input;
capacitance : 1;
pin (A[0:3]) {
capacitance : 2;
}
pin (A[3]) {
capacitance : 2.5;
}
}
bus (B) {
bus_type : bus4;
direction : input;
capacitance : 2;
}
pin (E) {
direction : input ;
capacitance : 2 ;
bus(X) {
bus_type : bus4;
direction : output;
capacitance : 1;
pin (X[0:3]) {
function : "A & B’";
timing() {
related_pin : "A B";
/* A[0] and B[0] are related to X[0],
A[1] and B[1] are related to X[1], etc. */
}
}
}
}