Vim nws qhov me me, lub teeb yuag, thiab kev siv hluav taws xob tsawg,LCD kua siv lead ua zaubyog siv nyob rau hauv ntau yam kev siv. Piv txwv li, raws li cov zaub vaj huam sib luag rau cov dav hlau, tso tsheb hlau luam, thiab nkoj, qhov chaw nyob los ntawm thawj CRT cov lus tuaj yeem raug txo, cov khoom hnyav tuaj yeem raug txo, thiab kev ua haujlwm tuaj yeem txhim kho.
Qhov kev tsim no siv lub cim LCD nrog rau kev kos Si.tronix ST7066U nraaj maub los ntawm Spartan -3E pawg thawj coj saib kev loj hlob, uas siv: (1) Ib qho cim qhia ntawm txhua txoj haujlwm thiab puv npo thiab puv npo ntawm cov cim ; (2) Cov zaub ntawm cov cim kev cai (cov cim) thiab tag nrho lub vijtsam txav zaub ntawm tus kheej cov cim. Ntawm lawv, graphic controller [1] yog lub luag haujlwm rau kev txais cov lus txib thiab cov ntaub ntawv thiab xa mus rau LCD zaub.
1 Sitronix ST7066U Graphics Controller
Tus maub los muaj peb qhov chaw cia sab hauv, DD RAM, CGROM, thiab CG RAM, uas yuav tsum tau pib ua ntej xa cov ntaub ntawv.
(1) DD RAM (cov ntaub ntawv qhia RAM)
Cov cim cim yog khaws cia. Lub cev, DD RAM muaj tag nrho ntawm 80 tus cwj pwm txoj haujlwm, txhua kab muaj 40 tus cim, tab sis tsuas yog 16 tuaj yeem tso tawm thiab qhov seem 24 tsis tso tawm. Ua ntej nyeem ntawv lossis sau ntawv, tus lej chaw nyob yuav tsum tau pib ua ntej. Qhov chaw nyob txee tuaj yeem khaws cia tsis tu ncua lossis tuaj yeem nce lossis txo qis los ntawm 1 tom qab nyeem lossis sau ntawv.
(2) CG ROM (Cim Generator ROM)
Ib qho font bitmap uas muaj txhua tus cim ua ntej txiav txim siab.
(3) CG RAM (cov cim generator RAM)
Muaj 8-ntsis kev cai cim bitmap. Txhua tus cim kev cai me ntsis muaj 5 cov ntsiab lus hauv 8-ntsis bitmap. Kev siv tshwj xeeb yog tib yam li DD RAM.
1.1 Interface Signals nrog FPGA
LCD thiab FPGA interface signals [2] yog: (1) pab kom lub teeb liab LCD_E; (2) sau npe xaiv teeb liab LCD_RS; (3) nyeem / sau tswj lub teeb liab LCD_RW; (4) plaub kab ntawv LCD thiab StrataFlash cov ntaub ntawv kab SF_D<11:8>Multiplexing.
1.2 Timing Analysis
Cov ntaub ntawv tus nqi ntawm SF_D<11:8>, LCD_RS, LCD_RW yuav tsum tau tsim thiab ruaj khov rau yam tsawg 40 ns ua ntej LCD_E mus siab, thiab LCD_E tseem siab rau yam tsawg 230n ib. Hauv ntau daim ntawv thov, LCD_RW ib txwm qis vim cov ntaub ntawv tsis nquag nyeem los ntawm cov zaub.
