Feem ntau yuam kev 17: Cov npav npav no txhua tus rub los ntawm cov resistors, yog li kuv xav tias xis nyob.

Kev daws teeb meem zoo: Muaj ntau ntau yam laj thawj vim li cas cov teeb liab yuav tsum rub thiab nqis, tab sis tsis yog txhua tus yuav tsum tau rub. Lub rub-up thiab rub-down resistor rub lub teeb liab tawm tswv yim yooj yim, thiab tam sim no tsawg dua kaum ntawm microamperes, tab sis thaum lub teeb liab tsav tau rub, tam sim no yuav mus txog qib milliamp. Lub kaw lus tam sim no feem ntau muaj 32 qhov chaw nyob cov ntaub ntawv txhua, thiab tej zaum yuav yog Yog tias lub tsheb npav 244/245 raug rho tawm thiab lwm yam teeb liab raug rub, ob peb lub zog siv hluav taws xob yuav raug siv rau cov resistors (tsis txhob siv lub tswv yim ntawm 80 xees ib kilowatt-teev los kho cov ob peb watts ntawm lub hwj chim noj, yog vim li cas yog down Saib).

Feem ntau yuam kev 18: Peb lub cev muaj zog los ntawm 220V, yog li peb tsis tas yuav txhawj txog kev siv hluav taws xob.

Cov kev daws teeb meem zoo: kev tsim hluav taws xob qis tsis yog tsuas yog txuag lub zog xwb, tab sis kuj tseem txo cov nqi ntawm cov khoom siv hluav taws xob thiab cov tshuab cua txias, thiab txo cov kev cuam tshuam ntawm hluav taws xob hluav taws xob hluav taws xob thiab thermal suab nrov vim qhov txo qis tam sim no. Raws li qhov ntsuas kub ntawm cov cuab yeej txo qis, lub neej ntawm cov cuab yeej txuas ntxiv txuas ntxiv (kev ua haujlwm kub ntawm cov khoom siv hluav taws xob nce ntxiv los ntawm 10 degrees, thiab lub neej luv luv los ntawm ib nrab). Kev siv hluav taws xob yuav tsum tau txiav txim siab txhua lub sijhawm.

Feem ntau yuam kev 19: Lub zog noj ntawm cov chips me me no tsawg heev, tsis txhob txhawj txog nws.

Kev daws qhov zoo: Nws yog ib qho nyuaj rau kev txiav txim siab lub zog noj ntawm lub sab hauv tsis nyuaj nti. Nws yog tsuas yog txiav txim los ntawm qhov tam sim no ntawm tus pin. ABT16244 siv tsawg dua 1 mA yam tsis muaj load, tab sis nws qhov taw qhia yog txhua tus pin. Nws tuaj yeem tsav lub nra ntawm 60 mA (xws li kev sib tw ntawm kaum ntawm ohms), uas yog, qhov siab tshaj plaws ntawm lub zog siv ntawm tag nrho cov load tuaj yeem ncav cuag 60 * 16 = 960mA. Tau kawg, tsuas yog cov khoom siv hluav taws xob tam sim no loj heev, thiab cov cua sov poob rau ntawm qhov load.

Feem ntau yuam kev 20: Yuav ua li cas nrog cov tsis siv I/O ports ntawm CPU thiab FPGA? Koj tuaj yeem tso nws tseg thiab tham txog nws tom qab.

Cov kev daws teeb meem zoo: Yog tias qhov tsis siv I / O cov chaw nres nkoj tau tso tseg, lawv yuav dhau los ua cov lus qhia tawm tswv yim nrog kev cuam tshuam me ntsis los ntawm lub ntiaj teb sab nraud, thiab kev siv hluav taws xob ntawm MOS cov cuab yeej yog nyob ntawm tus naj npawb ntawm flips ntawm lub rooj vag circuit. Yog tias nws rub tawm, txhua tus pin tseem yuav muaj microampere tam sim no, yog li txoj hauv kev zoo tshaj plaws yog muab tso rau hauv qhov tso zis (tau kawg, tsis muaj lwm yam teeb liab nrog kev tsav tsheb tuaj yeem txuas rau sab nraud).

Common Mistake 21: Muaj ntau lub qhov rooj sab laug ntawm FPGA no, yog li koj tuaj yeem siv nws.

Cov kev daws teeb meem zoo: Kev siv hluav taws xob ntawm FGPA yog qhov sib npaug rau tus naj npawb ntawm flip-flops siv thiab tus naj npawb ntawm flips, yog li kev siv hluav taws xob ntawm tib hom FPGA ntawm qhov sib txawv thiab cov sij hawm sib txawv yuav yog 100 npaug sib txawv. Txo tus naj npawb ntawm flip-flops rau kev kub ceev flipping yog txoj hauv kev los txo FPGA lub zog noj.

Feem ntau yuam kev 22: Lub cim xeeb muaj ntau yam tswj cov cim. Kuv lub rooj tsavxwm tsuas yog yuav tsum siv OE thiab WE cov cim. Lub nti xaiv yuav tsum yog hauv av, kom cov ntaub ntawv tawm sai dua thaum lub sijhawm nyeem ntawv.

Kev daws teeb meem zoo: Lub zog noj ntawm feem ntau nco thaum xaiv nti siv tau (tsis hais txog OE thiab WE) yuav ntau dua 100 npaug ntau dua thaum xaiv nti tsis raug. Yog li ntawd, CS yuav tsum tau siv los tswj cov nti kom ntau li ntau tau, thiab lwm yam yuav tsum tau ua. Nws yog ua tau kom luv luv qhov dav ntawm lub nti xaiv mem tes.

Feem ntau yuam kev 23: Txo kev siv hluav taws xob yog txoj haujlwm ntawm cov neeg ua haujlwm kho vajtse, thiab tsis muaj dab tsi cuam tshuam nrog software.

Cov kev daws teeb meem zoo: Cov khoom siv tsuas yog ib theem xwb, tab sis cov software yog tus ua yeeb yam. Kev nkag tau ntawm yuav luag txhua lub nti ntawm lub npav thiab qhov ntxeev ntawm txhua lub teeb liab yuav luag tswj los ntawm software. Yog tias lub software tuaj yeem txo tus naj npawb ntawm kev nkag mus rau lub cim xeeb sab nraud (siv ntau cov npe sib txawv, Kev siv ntau dua ntawm CACHE, thiab lwm yam), cov lus teb raws sij hawm rau kev cuam tshuam (kev cuam tshuam feem ntau qis qis nrog rub-up resistors), thiab lwm yam. kev ntsuas tshwj xeeb rau cov laug cam tshwj xeeb yuav ua rau muaj txiaj ntsig zoo los txo kev siv hluav taws xob. Rau lub rooj tsavxwm tig tau zoo, kho vajtse thiab software yuav tsum tau tuav ntawm ob txhais tes!

Feem ntau yuam kev 24: Vim li cas cov teeb liab no overshooting? Ntev npaum li qhov kev sib tw zoo, nws tuaj yeem raug tshem tawm.

Kev daws teeb meem zoo: Tsuas yog qee qhov tshwj xeeb teeb liab (xws li 100BASE-T, CML), muaj kev kub ntxhov. Tsuav nws tsis loj heev, nws tsis tas yuav tsum tau ua kom haum. Txawm hais tias nws sib phim, nws tsis tas yuav phim qhov zoo tshaj plaws. Piv txwv li, qhov tso zis impedance ntawm TTL tsawg dua 50 ohms, thiab qee qhov txawm tias 20 ohms. Yog hais tias xws li ib tug loj txuam kuj yog siv, tam sim no yuav loj heev, lub hwj chim noj yuav tsis tsim nyog, thiab lub teeb liab amplitude yuav tsawg dhau los siv. Tsis tas li ntawd, qhov tso zis impedance ntawm lub teeb liab dav dav thaum tso tawm cov qib siab thiab cov zis qis qis tsis zoo ib yam, thiab nws tseem tuaj yeem ua tiav qhov sib txuam. Yog li ntawd, kev sib piv ntawm TTL, LVDS, 422 thiab lwm yam teeb liab tuaj yeem ua tau raws li ntev li ntev tau ua tiav.