PAL16X4 PAL DESIGN SPECIFICATION P7031 BIRKNER/COLI 07/12/81 BETWEEN LIMITS COMPARATOR/REGISTER MMI SUNNYVALE, CALIFORNIA CLK LOAD CLEAR B0 B1 B2 B3 NC /OC2 GND /OC1 /NE /EQ A3 A2 A1 A0 /LT /GT VCC IF(OC2) LT = (A3*/B3) ;B3=L, A3=H + (A3:*:B3) * (A2*/B2) ;B2=L, A2=H + (A3:*:B3) * (A2:*:B2) * (A1*/B1) ;B1=L, A1=H + (A3:*:B3) * (A2:*:B2) * (A1:*:B1) * (A0*/B0) ;B0=L, A0=H IF(OC2) GT = (/A3*B3) ;B3=H, A3=L + (A3:*:B3) * (/A2*B2) ;B2=H, A2=L + (A3:*:B3) * (A2:*:B2) * (/A1*B1) ;B1=H, A1=L + (A3:*:B3) * (A2:*:B2) * (A1:*:B1) * (/A0*B0) ;B0=H, A0=L IF(OC2) EQ = (A3:*:B3) * (A2:*:B2) * (A1:*:B1) * (A0:*:B0) ;COMPARE EQUAL IF(OC2) NE = (A3:+:B3) + (A2:+:B2) + (A1:+:B1) + (A0:+:B0) ;COMPARE NOT EQUAL /A3 := (/A3)*/LOAD ;HOLD REG A3 + (/B3)* LOAD ;LOAD REG A3 + CLEAR ;CLEAR REG A3 /A2 := (/A2)*/LOAD ;HOLD REG A2 + (/B2)* LOAD ;LOAD REG A2 + CLEAR ;CLEAR REG A2 /A1 := (/A1)*/LOAD ;HOLD REG A1 + (/B1)* LOAD ;LOAD REG A1 + CLEAR ;CLEAR REG A1 /A0 := (/A0)*/LOAD ;HOLD REG A0 + (/B0)* LOAD ;LOAD REG A0 + CLEAR ;CLEAR REG A0 FUNCTION TABLE CLK /OC1 /OC2 LOAD CLEAR B3 B2 B1 B0 A3 A2 A1 A0 LT EQ NE GT ;CONTROL BUS REG ; /OC OPERATIONS BBBB AAAA --STATUS--- COMMENTS ;CLK 1 2 LOAD CLEAR 3210 3210 LT EQ NE GT (HEX VALUES) -------------------------------------------------------------------------- C L X X H XXXX LLLL X X X X CLEAR REG C L X H L LLLL LLLL X X X X LOAD REG (0) X L L L L LLLL LLLL L H L L COMPARE (0 EQ 0) X L L L L LLLH LLLL L L H H COMPARE (1 GT 0) X L X L L XXXX LLLL X X X X READ REG (0) C L X X H XXXX LLLL X X X X CLEAR REG C L X H L LHLH LHLH X X X X LOAD REG (5) X L L L L LLLL LHLH H L H L COMPARE (0 LT 5) X L L L L LHLH LHLH L H L L COMPARE (5 EQ 5) X L L L L HHHH LHLH L L H H COMPARE (F GT 5) X L X L L XXXX LHLH X X X X READ REG (5) C L X X H XXXX LLLL X X X X CLEAR REG C L X H L HLHL HLHL X X X X LOAD REG (A) X L L L L LHLL HLHL H L H L COMPARE (4 LT A) X L L L L HLHL HLHL L H L L COMPARE (A EQ A) X L L L L HLHH HLHL L L H H COMPARE (B GT A) X L X L L XXXX HLHL X X X X READ REG (A) C L X X H XXXX LLLL X X X X CLEAR REG C L X H L HHHH HHHH X X X X LOAD REG (F) X L L L L HHHL HHHH H L H L COMPARE (E LT F) X L L L L HHHH HHHH L H L L COMPARE (F EQ F) X L X L L XXXX HHHH X X X X READ REG (F) C L X L L XXXX HHHH X X X X HOLD (F) X H X X X XXXX ZZZZ X X X X TEST HI-Z (/OC1=H) X X H X X XXXX XXXX Z Z Z Z TEST HI-Z (/OC2=H) -------------------------------------------------------------------------- DESCRIPTION THE DEVICE CONTINUOUSLY COMPARES THE VALUE OF BUS (B3-B0) WITH THE VALUE OF THE REGISTER (A3-A0) AND REPORTS THE STATUS ON OUTPUTS LT, EQ, NE, AND GT: * LT INDICATES THAT B IS LESS THAN A * EQ INDICATES THAT B IS EQUAL TO A * NE INDICATES THAT B IS NOT EQUAL TO A * GT INDICATES THAT B IS GREATER THAN A STATUS BUS REG /OC1 /OC2 CLK LOAD CLEAR LT EQ NE GT B3-B0 A3-A0 OPERATION ----------------------------------------------------------------------- H X X X X X X X X X Z REG HI-Z X H X X X Z Z Z Z X X STATUS HI-Z L X X L L X X X X X A READ REG X X C H L X X X X B B LOAD REG X X C L L X X X X X A HOLD X X C X H X X X X X L CLEAR REG X L X L L STATUS B A COMPARE -----------------------------------------------------------------------