PLA vs ROM
ROM (Nyeem Tsuas Nco) thiab PLA (Programmable Logic Array) yog siv los ua cov haujlwm logic. Ob leeg siv 'Sum of Products' logic configuration, uas muaj ib tug thawj array ntawm THIAB rooj vag thiab ib tug thib ob array ntawm LOS SIS lub rooj vag. LUB SIJ HAWM (Sum) yog siv rau cov khoom tawm ntawm THIAB (cov khoom lag luam) arrays.
ROM (Read Only Memory)
ROM yog ua los ntawm AND rooj vag array thiab LOS SIS rooj vag array. THIAB array muab tag nrho cov kev sib txuas ntawm cov khoom siv, thiab OR array yog siv los xaiv cov kev sib txuas tsim nyog. Yog li ntawd, THIAB array yeej ib txwm kho. Piv txwv li, hauv peb lub tswv yim (cia hais), THIAB array tsim tag nrho cov kev sib txuas (cov ntsiab lus khoom) ntawm ABC, ABC', AB'C, AB'C', A'BC, A'BC', A'B 'C, A'B'C' qhov twg ' implies lub complement (TSIS).
Tom qab ntawd OR lub rooj vag tuaj yeem siv los xaiv cov khoom tsim nyog cov ntsiab lus los siv cov kev ua haujlwm tau muab. Txhua qhov kev ua haujlwm ntawm A, B, C tuaj yeem siv tau siv cov ntsiab lus ntawm cov khoom.
Piv txwv
f(A, B, C)=AB + BC=ABC + ABC' + A'BC
Ib yam li ib qho array ntawm LOS SIS lub rooj vag tuaj yeem siv tau ib qho array ntawm logic functions. Yog li ROM yog siv los khaws cov kev pab cuam. Programming ROM txhais tau tias teeb tsa cov OR array los ntawm xaiv cov khoom tsim nyog.
PLA (Programmable Logic Array)
PLA ib yam nkaus yog ua los ntawm ob LUB OR thiab THIAB arrays, tab sis ob qho tib si arrays yog configurable tsis zoo li hauv ROM. Qhov no kuj muab 'Sum ntawm Cov Khoom' lub sij hawm, tab sis nyob rau hauv ib txoj kev sib txawv. Txij li cov ntsiab lus rau THIAB cov rooj vag tseem ua tau, nws tuaj yeem muab cov ntsiab lus ntau yam khoom xws li AB, BC', C thiab lwm yam. Yog li nws yooj yim dua los siv cov logic zog piv rau ROM.
Piv txwv li, AB + BC tuaj yeem siv ncaj qha los ntawm kev xaiv A, B rau ib qho AND rooj vag, B, C rau lwm qhov AND rooj vag thiab ua cov khoom tawm ntawm cov AND rooj vag mus rau qhov nkag ntawm lub rooj vag.
Qhov txawv ntawm ROM thiab PLA yog dab tsi?
1. Hauv PLA ob qho tib si THIAB thiab LOSSIS arrays yog configurable tsis zoo li nyob rau hauv ROM, whereas tsuas yog LUB rooj vag array yog configurable.
2. PLA muaj peev xwm coj 'tsis tu cov nqe lus' (Boolean overlaps) rau hauv tus account uas ROMs tsis muaj peev xwm.
3. ROM muaj tag nrho cov kev sib txuas ntawm cov khoom siv, thiab yog li ntawd, suav hais tias yog lub hom phiaj dav dav tshaj plaws kev sib xyaw ua ke ntawm cov cuab yeej sib piv rau PLA, uas tsis muaj tag nrho cov kev sib txuas.
