PLE8P4                                             PLE DESIGN SPECIFICATION
P5011                                                ULRIK MUELLER 04/01/83
4-BIT MAGNITUDE COMPARATOR
MMI SANTA CLARA, CALIFORNIA
.ADD A0 A1 A2 A3 B0 B1 B2 B3
.DAT EQ NE LT GT


EQ =  A3:*:B3 *  A2:*:B2 *  A1:*:B1 *  A0:*:B0 ; A = B

NE =  A3:+:B3 +  A2:+:B2 +  A1:+:B1 +  A0:+:B0 ; A NOT = B

LT = /A3 * B3                                  ; A3 > B3
   +  A3:*:B3 * /A2 * B2                       ; A2 > B2
   +  A3:*:B3 *  A2:*:B2 * /A1 * B1            ; A1 > B1
   +  A3:*:B3 *  A2:*:B2 * /A1:*:B1 * /A0 * B0 ; A0 > B0

GT =  A3 */B3                                  ; A3 < B3
   +  A3:*:B3 *  A2 */B2                       ; A2 < B2
   +  A3:*:B3 *  A2:*:B2 *  A1 */B1            ; A1 < B1
   +  A3:*:B3 *  A2:*:B2 *  A1:*:B1 *  A0 */B0 ; A0 < B0


DESCRIPTION

THIS PLE8P4 COMPARES TWO 4-BIT NUMBERS (A3-A0 AND B3-B0) TO ESTABLISH IF THEY
ARE EQUAL (A = B  =>  EQ=H), NOT EQUAL (A NOT = B  =>  NE=H), LESS THAN
(A < B  =>  LT=H), OR GREATER THAN (A > B  =>  GT=H) AND REPORTS THE
COMPARISON STATUS ON THE OUTPUTS (EQ, NE, LT, GT) AS ILLUSTRATED IN THE
OPERATIONS TABLE BELOW.

THE PLE8P4 ALSO FEATURES THREE-STATE OUTPUTS WITH TWO ACTIVE-LOW OUTPUT ENABLE
CONTROL PINS (/E1 AND /E2).


      INPUT NUMBERS    COMPARISON  STATUS
      A3-A0   B3-B0      EQ  NE  LT  GT        OPERATION
     -------------------------------------------------------------------
        A   =   B        H   L   L   L         COMPARE A EQUAL TO B
        A NOT = B        L   H   X   X         COMPARE A NOT EQUAL TO B
        A   <   B        L   H   H   L         COMPARE A LESS THAN B
        A   >   B        L   H   L   H         COMPARE A GREATER THAN B
     -------------------------------------------------------------------