ROM Code ConvertersMM4220EK/MM5220EKBCDIC-to-EBCDIC and ASCII-to-EBCDIC code converters3:3:~NNom~.......3:3:U'1NNom~general descriptionTheMM4220EK/MM5220EK isa 1024-bitread onlymemory that has been programmed to convertboth Binary Coded Decimal Interchange Code(BCDIC) and the American Standard Code forInformation I nterchange (ASCII) to Extended BinaryCoded Decimal Interchange Code (EBCDIC).The BCDIC-to-EBCDIC converter is located in thefirst 64 8-bit bytes of the ROM. The unused paritycheck bit (the most significant input BCDIC bit) isalways a "0".The ASCII-to-EBCDIC converter is located in thesecond 64 8-bit bytes of the ROM. Thus, the inputASCII code in addresses 64 through 127 has a "1"in the most significant (A7) bit which is used withthe selection logic. The resulting 6-bit ASCII inputis for display-only upper case and numericalcodes, since it will not accept the control commandsor the lower case characters.device characteristicsFor full electrical, environmental and mechanicaldetails, refer to the MM4220/MM5220 1024-bitread only memory data sheet.typical applicationconnection diagram-12V----------------+~t_....,b, 1b, 1.5V--+--------------I--II-4---_--A,8,6.8K,TYPICAL,B LINESGATES OM740(}A, 14 V,,A, 13A, 11b, 4A,8,8, 11 A,b, Sb, Ab, 8"CODE"A,11A,10'" "A, 18MM4220EK/MM52Z0EK8,s,s,, S,~8, 10 A,8,8, 18 A,8, 17V""8, 16A,MODECONTROLl.OK,TYPICAL,1UNESV"+12V-----.~t--"""I12tA,"CHIP ENABLE ___..J10 j.:8::.-, ------11---1111"8;;..' ---~t--IOlL/TTL LOGIC8, 10 158, 11 14 A,V" 12 13TOP VIEWCHIPENABLEtMOOE CONTROL ------'Logic LeulsDTlfTTl (except at MQS/ROM Interface)logic "l",+!iV, nom. Logic "Q",glound, nom.MOS/ROM Inputs & OutputlogIc "l",more neptive. logic "D",more positlYetMode COntrol = logic "0"AB= llJgic"l"·Chlp Enable = Logic "1" to obtain outputs193
code conversion tablesFUNCTION CODe FUNCTION CODeINPUT OUTPUT INPUT OUTPUT INPUT OUTPUT INPUT OUTPUTCC0ROM BCOIC EBCDICBCOICEBCDIC00ROM ASCII EBCDICASCII EBCDICADDRESS SYMBOL SYMBOL E • A 8 4 2 1 0 1 2 3 4 5 6 7 0ADDRESS SYMBOL SYMBOL E b6 bS b4 b3 b2 b1 0 1 2 3 4 5 6 7@> 0 Space Space 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 64 @ 1 0 0 0 0 0 0 0 1 .1 1 1 1 0 01 1 1 0 0 0 0 0 0 1 1 1 1 1 0 0 0 1 6' A A 1 0 0 0 0 0 1 1 1 0 0 0 0 0 1, , ,0 0 0 0 0 1 0 1 1 1 1 0 0 1 0 66 8 8 1 0 0 0 0 1 0 1 1 0 0 0 0 1 03 3 3 0 0 0 0 0 1 1 1 1 1 1 0 0 1 1 67 C C 1 0 0 0 0 1 1 1 1 0 0 0 0 1 14 4 4 0 0 0 0 1 0 0 1 1 1 1 0 1 0 0 68 0 0 1 0 0 0 1 0 0 1 1 0 0 0 1 0 05 5 5 0 0 0 0 1 0 1 1 1 1 1 0 1 0 1 69 E E 1 0 0 0 1 0 1 1 1 0 0 0 1 0 16 6 6 0 0 0 0 1 1 0 1 1 1 1 0 1 1 0 70, , 1 0 0 0 1 1 0 1 1 0 0 0 1 1 07 7 7 0 0 0 0 1 1 1 1 1 1 1 0 1 1 1 71 G G 1 0 0 0 1 1 1 1 1 0 0 0 1 1 18 0 0 0 1 0 0 0 1 1 1 1 1 0 0 0H H 1 0 0 1 0 0 0 1 1 0 0 1 0 0 0• •9 9 9 0 0 0 1 0 0 1 1 1 1 1 1 0 0 1 " 73 , , 1 0 0 1 0 0 1 1 1 0 0 1 0 0 110 0 0 0 0 0 1 0 1 0 1 1 1 1 0 0 0 0 741 0 0 1 0 1 0 1 1 0 1 0 0 0 111 #0. - " "·0 0 1 0 1 1 0 1 1 1 1 0 1 1 75 K K 1 0 0 1 0 1 1 1 1 0 1 0 0 1 012 @lor' @> 0 0 0 1 1 0 0 0 1 1 1 1 1 0 0 76 , , 1 0 0 1 1 0 0 1 1 0 1 0 0 1 1013 0 0 0 1 1 0 1 0 1 1 1 1 0 1 0 77 M M 1 0 0 1 1 0 1 1 1 0 1 0 1 0 014 > > 0 0 0 1 1 1 0 0 1 1 0 1 1 1 0 78 N N 1 0 0 1 1 1 0 1 1 0 1 0 1 0 115 J(TM) TM 0 0 0 1 1 1 1 0 0 0 1 0 0 1 1 79 0 0 1 0 0 1 1 1 1 1 1 0 1 0 1 1 016 Space Space 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 80 P P 1 0 1 0 0 0 0 1 1 0 1 0 1 1 117 , , 0 0 1 0 0 0 1 0 1 1 0 0 0 0 1 81 a a 1 0 1 0 0 0 1 1 1 0 1 1 0 0 01 1 A A 0 1 0 0 0 1 1 0 1 1 0 0 119 T T 0 0 1 0 0 1 1 1 1 1 0 0 0 1 1 83 S S 1 0 1 0 0 1 1 1 1 1 0 0 0 1 018 S S 0 0 1 0 0 1 0 1 1 1 0 0 0 1 0.,,.U U 0 0 1 0 1 0 0 1 1 1 0 0 1 0 0 84 T T 1 0 1 0 1 0 0 1 1 1 0 0 0 1 1V V 0 0 1 0 1 0 1 1 1 1 0 0 1 0 1 8' U U 1 0 1 0 1 0 1 1 1 1 0 0 1 0 0W W 0 0 1 0 1 1 0 1 1 1 0 0 1 1 0 86 V V 1 0 1 0 1 1 0 1 1 1 0 0 1 0 1"23 X X 0 0 1 0 1 1 1 1 1 1 0 0 1 1 1 87 W W 1 0 1 0 1 1 1 1 1 1 0 0 1 1 0,.'425'6"YZf(RM)orYZAM%0000000000111111111100001001100101011,0011111111110000011011000010001001010888990919'XYZI,XYZI,111110000011111111110000100110010101110011111111000000001110100101000010110% ('9 0 0 1 1 1 0 1 0 1 0 0 1 1 1 0 93 I I 1 0 1 1 1 0 1 0 1 0 1 1 1 0 130 , , 0 0 1 1 1 1 0 0 1 0 0 1 0 1 0 94 """0. ",1 0 1 1 1 1 0 0 1 0 1 1 1 1 131 ffi 0 0 1 1 1 1 1 0 1 1 1 1 1 1 032 0 1 0 0 0 0 0 0 1 1 0 0 0 0 0330 1 0 0 0 0 1 1 1 0 1 0 0 0 1 97,1 1 0 0 0 0 1 0 1 0 1 1 0 1 034 " K " K 0 1 0 0 0 1 0 1 , 0 1 0 0 1 0 - 98 1 1 0 0 0 1 0 0 1 1 1 1 1 1 135 , , 0 1 0 0 0 1 1 1 1 0 1 b 0 1 1 99 0 1 1 0 0 0 1 1 0 1 1 1 1 0 1 136 M M 0 1 0 0 1 0 0 1 1 0 1 0 1 0 0 100 $ $ 1 1 0 0 1 0 0 0 1 0 1 1 0 1 137 N N 0 1 0 0 1 0 , 1 1 0 1 0 1 0 1 101 % % 1 1 0 0 1 0 1 0 1 1 0 1 1 0 038 . ·0 0 0 1 0 0 1 1 0 1 1 0 1 0 1 1 0 102 1 1 0 0 1 1 0 0 1 0 1 0 0 0 039 P P 0 1 0 0 1 , 1 , 1 0 1 0 1 1 1 103 1 1 0 0 1 1 1 0 1 1 1 1 1 0 140 0 0 0 , 0 1,0 0 0 1 1 0 1 1 0 0 0 104 I I 1 1 0 1 0 0 0 0 1 0 0 1 1 0 1I 41 A A 0 1 0 0 0 1 1 1 0 1 1 0 0 1 105 I 1 1 0 1 0 0 1 0 1 0 1 1 1 0 1050 8 8 0 1 1 0 0 1 0 1 1 0 0 0 0 1 0 114 , , 1 1 1 0 0 , 0 , , , , 0 0 , 051 C C 0 1 1 0 0 1 1 1 1 0 0 0 0 1 1 '1552 0 0 0 1 1 0 1 0 0 1 1 0 0 0 1 0 0 11653 E E 0 1 1 0 1 0 1 1 1 0 0 0 1 0 1 11754 , , 0 1 1 0 1 1 0 1 1 0 0 0 1 1 055 G G 0 1 1 0 1 1 1 1 1 0 0 0 1 1 1 "' 1193 3 1 1,, 0 0, 1 , 1 0 0 , 15 5 1 1 0 1 0,1 1 1 0 0 4 4,1 0 1 0 0 1 1 0,1 0 0,6 6 1 1, , ,0,1 0, , ,1,0,1,07 7 0 1 1 0 1~ 57 , , 0 1 1 1 0 0 1 1 1 0 0 1 0 0 1H H 0 1 1 1 0 0 0 1 1 0 0 , 0 0 0,,. . · , 1 , , 0 0 0 1 1 , , , 0 0 09 9 1 ,'"0 0 , 1 1 1 1 1 0 0 158 0 1 1 1 0 1 0 0 1 1 0 1 1 1 1, ,'"1 0 1 0 0 1 , 0 1 059 0 1 1 1 0 1 1 0 1 0 0 1 0 1 1 123 1 1 0 , 1 0 , 0 , , 1 1 060 J:l or) 0 0 1 1 1 1 0 0 0 1 1 0 1 0 1 0 124 < < , 0 0 0 1 0 0 1 1 0 061 I I 0 1 1 1 1 0 1 0 1 0 0 1 1 0 1, ,'"1 0 , 0 , , 1 06' < < 0 1 1 1 1 1 0 0 1 0 0 1 1 0 0 126 > > 1 1 , 0 0 0 1 1 063 , 0 1 1 1 1 1 1 0 1 1 1 1 1 0 1, 1 1 , , ,'"1 1 0 , , 0 , 1 1 ,194