RS-tig-ntog. Lub hauv paus ntsiab lus ntawm cov lag luam, tej kos duab, kev hloov cov lus

Ua - ib tug yooj yim ntaus ntawv yog ib cov tshuab. Nws muaj ob lub xeev stability. Ib tug ntawm cov tej yam kev mob yog muab ib tug nqi "1", thiab lwm yam - "0". Txhais mob, thiab tus nqi ntawm cov binary ntaub ntawv uas yog cia nyob rau ntawd, tso zis rau Pib ntsais koj teeb yog txiav txim: Direct thiab inverted. Nyob rau hauv lub rooj plaub uas lub direct tso zis tej zaum yog tsim, uas sib raug rau ib tug logic ib, lub xeev ntawm flip-ntog hu ua lub tsev (lub peev xwm ntawm cov inverted tso zis yog zero). Yog hais tias qhov ncaj tso zis yog tsis muaj peev xwm, ces tus txhais mob no yog hu ua zero.

Chiv yog txwv kom muab zais los ntawm cov nram qab no nta:

1. Los ntawm cov qauv ntawm cov ntaubntawv povthawj siv ntaub ntawv (synchronous thiab asynchronous).

2. Los ntawm txoj kev tswj ntaub ntawv (statistics, dynamic, ib leeg-theem, multistage).

3. Los ntawm txoj kev ntawm realization ntawm cov zajlus kom sib txuas (JK-flip-ntog, RS-chiv, T-Triger, D-flip-flop thiab lwm yam).

Lub ntsiab tsis ntawm tag nrho cov hom ntawm chiv yog cov coob tus nqi ntawm lub tswv yim teeb liab ntev, qhov kev ncua sij hawm yuav tsum tau rau switching lub flip-ntog, thiab tas lub lag luam lub sij hawm.

Nyob rau hauv no tsab xov xwm, wb tham txog qhov no hom ntawm ntaus, raws li RS-flip-ntog. Lawv yog cov ntawm ob hom: synchronous thiab asynchronous.

Asynchronous RS-flip-ntog muaj ob kab raws kev (R thiab S) input. Qhov no ntaus ntawv ua hauj lwm raws li txoj kev hloov lub rooj.

Txwv tsis pub rau tej flip-ntog yog ib tug ua ke ntawm Pib ntsais koj teeb ntawm lub inputs ntawm tus dais, ua ib lub xeev ntawm tsis paub tseeb. No thaum lawv tseem muaj peev xwm yuav qhia raws li ib tug yuav tsum tau RtSt = 0. Nyob rau hauv nrhiav tus Karnaugh daim ntawv qhia tso tawm kom pom txoj cai txhais cov lag luam, uas yog hu ua tus yam ntxwv kab zauv: Q (t + 1) = St V R'tQt. Yog li RtSt yog pes tsawg.

Nyob rau tej daim duab qhia tau hais tias lub RS-flip-ntog asynchronous hom Nand thiab lub thib ob kev ua tau zoo nyob rau hauv NOR ntsiab.

Qhov thib ob hom - synchronous RS-txiav. Xws li ib tug ntaus ntawv yog structurally muaj peb ncaj qha inputs S, R, thiab C. Qhov txawv ntawm cov synchronous thiab asynchronous hom flip-ntog yog lub xub ntiag ntawm ib tug synchronization tawm tswv yim (C). Nws yog tsim nyog rau cov nram qab no yog vim li cas: vim hais tias nyob rau hauv lub ntaus ntawv inputs (logic caij) Pib ntsais koj teeb yuav muab xa mus tsis yeej ib txwm ib txhij. Qhov no yog vim lub fact tias lawv kis tau los ntawm ntau hom kev thiab tus xov tooj ntawm ntshav uas muaj ntau qeeb. Qhov no tshwm sim yog hu ua ib tug "match." Raws li ib tug ntawm xws li "cov txheej xwm" teeb liab qhov tseem ceeb tau yuav superimposed nyob rau yav dhau los qhov tseem ceeb ntawm cov lwm yam Pib ntsais koj teeb. Tag nrho cov no ua rau yus mus rau ib tug cuav tswb kiag li lawm.

Qhov no tshwm sim muaj peev xwm yuav tshem tawm los ntawm thov lub tswv yim Pib ntsais koj teeb lub sij hawm gating ntaus ntawv. Namely, nyob hauv lub tswv yim ntawm Nand rooj vag tsuas yog ncaj qha ntaub ntawv Pib ntsais koj teeb nkag tseem ceeb synchronizing pulses, lub sij hawm no cov ntaub ntawv rau lub tswv yim pib ntsais koj teeb muaj lub sij hawm mus xauv mus rau lub tswv yim.

Lub ntsiab mob rau tseeb lag luam ntawm switching logic theem nyob rau hauv lub RS-flip-flop thiab logic tswj los ntawm lawv - Rt unacceptability simultaneous txiav txim los yog teeb liab St, ib tug switching ntaus ntawv, thiab cov ntaub ntawv nqi ntawm cov qhov tso zis Q (t + 1) tig-ntog. Nyob rau hauv no hais txog, lub peev xwm series muaj tsuas synchronous ntsiab.

RS-hom flip-ntog synchronous yam ntxwv sawv cev los ntawm lub kab zauv: Q (t + 1) = StCt V R'tQt V QtC't.

Lub yees duab qhia tau hais tias lub RS-txhais synchronous hom Nand. Tswv yim THIAB rooj vag, TSIS zajlus kom chav tsev yog kis tau mus rau lub switching cov ntaub ntawv tswv yim S los yog R rau qhov tsim nyog inputs asynchronous RS ntaus latch nrog inverted tswv yim tsuas yog thaum lub tswv yim rau synchronous (C) lub teeb liab ntawm logic ib.