PAL16L8                                         PAL DESIGN SPECIFICATION
P7048                                                B. BRAFMAN 03/13/81
ERROR CORRECTION UNIT #2
MMI FIELD APPLICATIONS ENGINEER  YORBA LINDA, CALIFORNIA
/S3 /S2 /S1 /S0 B1 B0 /C3 /C2 /C1 GND
/C0 NC ERROR C0C C1C C2C C3C B0C B1C VCC


IF (VCC) /B1C = /S3* S2*/S1* S0* B1    ;CORRECTION OF B1
              +  S3*/B1                ;NO CORRECTION
              + /S2*/B1                ;NO CORRECTION
              +  S1*/B1                ;NO CORRECTION

IF (VCC) /B0C = /S3*/S2* S1* S0* B0    ;CORRECTION OF B0 
              +  S3*/B0                ;NO CORRECTION
              +  S2*/B0                ;NO CORRECTION
              + /S1*/B0                ;NO CORRECTION
              + /S0*/B0                ;NO CORRECTION

IF (VCC) /C3C =  S3*/S2*/S1*/S0* C3    ;CORRECTION OF C3
              + /S3*/C3                ;NO CORRECTION
              +  S2*/C3                ;NO CORRECTION
              +  S1*/C3                ;NO CORRECTION
              +  S0*/C3                ;NO CORRECTION

IF (VCC) /C2C = /S3* S2*/S1*/S0* C2    ;CORRECTION OF C2
              +  S3*/C2                ;NO CORRECTION
              + /S2*/C2                ;NO CORRECTION
              +  S1*/C2                ;NO CORRECTION
              +  S0*/C2                ;NO CORRECTION

IF (VCC) /C1C = /S3*/S2* S1*/S0* C1    ;CORRECTION OF C1
              +  S3*/C1                ;NO CORRECTION
              +  S2*/C1                ;NO CORRECTION
              + /S1*/C1                ;NO CORRECTION
              +  S0*/C1                ;NO CORRECTION

IF (VCC) /C0C = /S3*/S2*/S1* S0* C0    ;CORRECTION OF C0
              +  S3*/C0                ;NO CORRECTION
              +  S2*/C0                ;NO CORRECTION
              +  S1*/C0                ;NO CORRECTION
              + /S0*/C0                ;NO CORRECTION

IF (VCC) /ERROR = /S3*/S2*/S1*/S0      ;NO ERROR!


FUNCTION TABLE

S3 S2 S1 S0 B1 B0 C3 C2 C1 C0 B1C B0C C3C C2C C1C C0C ERROR

;                   BB   CCCC
;SSSS   BB   CCCC   10   3210
;3210   10   3210   CC   CCCC  ERROR     COMMENTS
----------------------------------------------------
 LLLL   HH   XXXX   HH   XXXX    L       NO ERROR
 LLLL   XX   HHHH   XX   HHHH    L       NO ERROR
 LLLL   LL   XXXX   LL   XXXX    L       NO ERROR
 LLLL   XX   LLLL   XX   LLLL    L       NO ERROR
 LHLH   HH   XXXX   LH   XXXX    H       CORRECT B1
 LHLH   LL   XXXX   HL   XXXX    H       CORRECT B1
 LLHH   HH   XXXX   HL   XXXX    H       CORRECT B0
 LLHH   LL   XXXX   LH   XXXX    H       CORRECT B0
 HLLL   XX   HHHH   XX   LHHH    H       CORRECT C3
 HLLL   XX   LLLL   XX   HLLL    H       CORRECT C3
 LHLL   XX   HHHH   XX   HLHH    H       CORRECT C2
 LHLL   XX   LLLL   XX   LHLL    H       CORRECT C2
 LLHL   XX   HHHH   XX   HHLH    H       CORRECT C1
 LLHL   XX   LLLL   XX   LLHL    H       CORRECT C1
 LLLH   XX   HHHH   XX   HHHL    H       CORRECT C0
 LLLH   XX   LLLL   XX   LLLH    H       CORRECT C0
----------------------------------------------------


DESCRIPTION

THIS PAL PERFORMS ERROR CORRECTION ON BITS B0-B1 AND CHECKS BITS
C0-C3 BASED ON THE 4 BIT ERROR SYNDROME S0-S3.