PLE5P8                                              PLE DESIGN SPECEFICATION
P5006                                                 ULRIK MUELLER 03/29/83
HEXADECIMAL TO SEVEN SEGMENT DECODER
MMI SANTA CLARA, CALIFORNIA
.ADD A B C D LT
.DAT /OA /OB /OC /OD /OE /OF /OG /DP


OA =     B*   /D      ; SEGMENT A
   +     B* C
   + /A*   /C*/D
   +  A*    C*/D
   + /A*       D
   +    /B*/C* D
   +             LT   ; IF LT=H MAKE BLANK TEST ON SEGMENT A

OB =       /C*/D      ; SEGMENT B
   +  A* B*   /D
   + /A*/B*   /D
   +  A*/B*    D
   + /A*   /C
   +             LT   ; IF LT=H MAKE BLANK TEST ON SEGMENT B

OC =       /C* D      ; SEGMENT C
   +  A*/B
   +        C*/D
   +  A*      /D
   +    /B*   /D
   +             LT   ; IF LT=H MAKE BLANK TEST ON SEGMENT C

OD = /A*/B*/C         ; SEGMENT D
   +    /B*    D
   +  A*/B* C
   +  A* B*/C
   + /A* B* C
   + /A* B*   /D
   +             LT   ; IF LT=H MAKE BLANK TEST ON SEGMENT D

OE = /A*   /C         ; SEGMENT E
   +        C* D
   + /A* B
   +  A* B*    D
   +             LT   ; IF LT=H MAKE BLANK TEST ON SEGMENT E

OF = /A*/B            ; SEGMENT F
   +    /B* C*/D
   +       /C* D
   +     B*    D
   + /A* B* C
   +             LT   ; IF LT=H MAKE BLANK TEST ON SEGMENT F

OG =     B*/C         ; SEGMENT G
   + /A* B
   +       /C* D
   +  A*       D
   +    /B* C*/D
   +             LT   ; IF LT=H MAKE BLANK TEST ON SEGMENT G

DP = LT               ; TURNS DP ON ONLY WHEN LT=H


DESCRIPTION

THIS EXAMPLE ILLUSTRATES THE USE OF A PLE5P8 AS A HEXADECIMAL TO SEVEN SEGMENT
DECODER.  THE DEVICE DECODES A 4-BIT BINARY INPUT (D,C,B,A) INTO THE SEVEN
SEGMENT OUTPUTS NEEDED TO DRIVE AN LED DISPLAY.  NOTE THAT THIS DESIGN IS AN
IMPROVEMENT FROM THE 74LS47 SINCE ALL SIXTEEN HEXADECIMAL DIGITS (0-F) CAN BE
DISPLAYED.  A LAMP TEST IS PROVIDED TO ILLUMINATE ALL SEVEN SEGMENTS AND THE
DECIMAL POINT (IF DP IS CONNECTED) BY BRINGING LAMP TEST HIGH (LT=HIGH)
REGARDLESS OF THE OTHER BINARY INPUTS.  THREE-STATE OUTPUTS ARE ALSO PROVIDED
WITH ONE ACTIVE LOW ENABLE PIN (/E1).


              !      INPUT    ! SEGMENT ! OUTPUT
        DIGIT ! LT  D C B A   !   ON    ! DISPLAY
       -------------------------------------------
          0   ! L   L L L L   ! ABCDEF  !    0
          1   ! L   L L L H   ! BC      !    1
          2   ! L   L L H L   ! ABDEG   !    2
          3   ! L   L L H H   ! ABCDG   !    3
          4   ! L   L H L L   ! BCDFG   !    4
          5   ! L   L H L H   ! ACDFG   !    5 
          6   ! L   L H H L   ! ACDEFG  !    6
          7   ! L   L H H H   ! ABC     !    7
          8   ! L   H L L L   ! ABCDEFG !    8
          9   ! L   H L L H   ! ABCFG   !    9
          A   ! L   H L H L   ! ABCEFG  !    A
          B   ! L   H L H H   ! CDEFG   !    b
          C   ! L   H H L L   ! ADEF    !    C
          D   ! L   H H L H   ! BCDEG   !    d
          E   ! L   H H H L   ! ADEFG   !    E
          F   ! L   H H H H   ! AEFG    !    F
          G   ! H   X X X X   ! ABCDEFG !    8 *
       -------------------------------------------


             * BLANK TEST OF DISPLAY