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Bridgetek BT81X (815/6) KEV TSWV YIM YUAV TSUM MUAJ Graphics Engine Control

May 09, 2019

Backlight Control Pin

Cov nrig dov tswj kev npuaj (BACKLIGHT) yog lub plhaub dav hloov (PWM) teeb liab los ntawm
ob lub npe: REG_PWM_HZ thiab REG_PWM_DUTY . REG_PWM_HZ qhia meej txog PWM tso tawm zaus,
qhov ntau yog 250-10000 Hz. REG_PWM_DUTY qhia txog cov haujlwm voj voog; qhov ntau yog 0-128. Tus nqi ntawm 0
txhais tau hais tias PWM tau txiav tawm thiab 128 txhais tau tias yuav ua rau.
Tus PUB BACKLIGHT yuav tso tawm tsawg tsawg thaum lub DISP pin tsis enabled (ie logic 0).


DISP Control Pin

DISP tus pin yog ib qho kev tawm tswv yim dav dav uas yuav siv tau los pab, los yog pib dua cov duab LCD. Lub
tus pin yog tswj los ntawm kev sau ntawv mus rau Tshooj 7 ntawm Reg_RPi npe, lossis tshuav 15 ntawm REG_GPIOX.


General Purpose IO koob

Tus BT815 / 6 tuaj yeem tsim kho kom siv tau txog li ntawm 4 GPIO. Cov koob taw los ntawm GPIO no yog tswj los ntawm
REG_GPIOX_DIR thiab REG_GPIOX cov npe. Xwb li cov GPIO0 thiab GPIO1 pins kuj ua tau
tswj los ntawm REG_GPIO_DIR thiab REG_GPIO kom muaj rov qab compatibility nrog FT800 / FT801.
Thaum QSPI muaj cai rau Quad hom, GPIO0 / IO2 thiab GPIO1 / IO3 pins siv los ua cov kab lus ntawm cov
QSPI.


Pins Tsav Saib Xyuas Tam Sim No
Cov zis khiav tawm ntawm cov zis pins yuav raug hloov raws li cov lus hauv qab no los ntawm kev sau ntawv mus rau ntsis [6: 2] ntawm
REG_GPIO npe lossis tsawg [14:10] ntawm Reg_GPIOX npe. Xwb, siv SPI hais kom PINDRIVE
los hloov tus neeg tus pin tsav lub zog.

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Lub Cav

BT815 / 6 muab mono audio tso tawm nrog qhov kev ua lag luam ntawm sigma-delta los ntawm cov zis tawm suab, AUDIO_L.
Nws tawm ob lub suab suab, lub suab synthesizer thiab cov ntaub ntawv playback.


4.7.1 Suab Synthesizer

Ib suab processor, AUDIO CAV, generates lub suab los ntawm ib lub tsev qiv ntawv me me ROM ntawm lub rooj tsis muaj.
Ua si rau cov lus suab hauv daim ntawv teev npe 4.3, ntsig txog lub npe REG_SOUND nrog tus nqi code thiab sau 1 rau
cov npe REG_PLAY. Lub REG_PLAY register nyeem 1 thaum cov nyhuv yog ua si thiab rov ua tus '0' thaum
cov nyhuv xaus. Qee cov suab teebmeem ua si tsis tu ncua kom txog sijhawm los yog qhia kom ua si tom ntej
suab nyhav. Los cuam tshuam cov nyhuv, sau tus nqi tshiab rau REG_SOUND thiab REG_PLAY cov npe; xws li sau ntawv
0 (Silence) mus rau REG_SOUND thiab 1 rau PEG_PLAY kom tsis txhob muaj suab zoo.
Lub suab ntim raug tswj los ntawm cov register register REG_VOL_SOUND. Tus 16-ntsis REG_SOUND register siv sijhawm
8-ntsis suab hauv lub qes qis. Rau tej lub suab, cim "pitch kho" hauv qab rooj, qhov siab 8 khoom
muaj qhov ntaus nqi MIDI. Rau cov suab no, tus nqi ntawm qhov xoom ntawm nqe lus qis A nruab nrab C. Rau lwm lub suab
lub siab byte ntawm REG_SOUND yog ignored.


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4.7.2 Suab Playback

Tus BT815 / 6 tuaj yeem ua si rov qab kaw suab los ntawm nws cov suab tso tawm. Ua li no, ntsaws lub suab qub

cov ntaub ntawv rau hauv BT815 / 6's RAM, thiab teem cov npe sau cov playback.

Cov npe tswj kev ua si yog:

REG_PLAYBACK_START: pib qhov chaw nyob ntawm cov suab ntaub ntawv

REG_PLAYBACK_LENGTH: qhov ntev ntawm lub suab ntaub ntawv, hauv paus

REG_PLAYBACK_FREQ: cov playback piv txwv zaus, hauv Hz

REG_PLAYBACK_FORMAT: hom playback, ib qho ntawm kev kawm LINTER, UPLAW SAMPLES, los yog ADPCM cov lus

REG_PLAYBACK_LOOP: yog tias xoom, tus qauv ua si ib zaug. Yog tias ib qho, tus qauv rov qab mus tas li

REG_PLAYBACK_PLAY: tus sau rau qhov chaw no ua rau pib lub suab playback, tsis hais txog kev sau ntawv '0' lossis '1'. Nyeem rov qab '1' thaum kev ua si tsis tu ncua, thiab '0' thaum ua si tiav

REG_VOL_PB: playback ntim, 0-255


Cov mono audio formats txaus siab yog 8-khoom PCM, 8-khoom yas ULAW thiab 4-khoom ntawm IMA-ADPCM. Rau
ADPCM_SAMPLES, txhua tus qauv yog 4 khoom, yog li ob qho kev kuaj yog packed ib byte, thawj qauv yog hauv cov khoom
0-3 thiab qhov thib ob yog hauv cov khoom 4-7.
Tam sim no lub playback nyeem pointer tau queried los ntawm kev nyeem cov lus REG_PLAYBACK_READPTR. Siv
ib qho qauv loj tsis, looping, thiab qhov nyeem pointer, tus tswv tsev MPU / MCU tuaj yeem muab dej nruam
ntawm suab.