{"id":20470,"date":"2023-12-14T09:39:44","date_gmt":"2023-12-14T08:39:44","guid":{"rendered":"https:\/\/www.md-elektronik.com\/?p=20470"},"modified":"2023-12-14T09:40:36","modified_gmt":"2023-12-14T08:40:36","slug":"gmsl","status":"publish","type":"post","link":"https:\/\/www.md-elektronik.com\/cs\/gmsl\/","title":{"rendered":"GMSL"},"content":{"rendered":"\n

Co znamen\u00e1 GMSL?<\/h2>\n

Zkratka znamen\u00e1 \u201eGigabit Multimedia Serial Link\u201c a ozna\u010duje technologii, p\u0159i n\u00ed\u017e je videosign\u00e1l p\u0159en\u00e1\u0161en digit\u00e1ln\u011b a nekomprimovan\u011b prost\u0159ednictv\u00edm koaxi\u00e1ln\u00edho kabelu. D\u00edky gigabitov\u00e9mu p\u0159ipojen\u00ed a vysok\u00e9 \u0161\u00ed\u0159ce p\u00e1sma je mo\u017en\u00e9 pomoc\u00ed GMSL p\u0159en\u00e1\u0161et digit\u00e1ln\u00ed HD video data pro vozidla. Vzhledem k tomu, \u017ee videosign\u00e1l je p\u0159en\u00e1\u0161en bez komprese, jsou vylou\u010den\u00e9 ve\u0161ker\u00e9 z\u00e1seky. Obraz se na monitoru zobrazuje v re\u00e1ln\u00e9m \u010dase a bez zpo\u017ed\u011bn\u00ed. Spolupr\u00e1ce serializ\u00e9r\u016f a deserializ\u00e9r\u016f v r\u00e1mci \u201erodiny\u201c umo\u017e\u0148uje pou\u017eit\u00ed r\u016fzn\u00fdch rozhran\u00ed na ka\u017ed\u00e9m konci spojen\u00ed.<\/p>\n

Kdo jsou v\u00fdrobci \u010dip\u016f na trhu?<\/h2>\n

GMSL vyvinula spole\u010dnost Maxim Integrated, americk\u00fd v\u00fdrobce integrovan\u00fdch obvod\u016f (IC). S\u00eddlo spole\u010dnosti se nach\u00e1z\u00ed v San Jose v Kalifornii. Dne 13. \u010dervence 2020 bylo ozn\u00e1meno, \u017ee ji chce spole\u010dnost Analog Devices p\u0159evz\u00edt za 20,91 miliardy dolar\u016f. Akvizice byla dokon\u010dena 26.\u00a0srpna 2021.<\/p>\n

Jak\u00e1 jsou pou\u017eit\u00ed?<\/h2>\n

Oblast\u00ed pou\u017eit\u00ed GMSL jsou pokro\u010dil\u00e9 asisten\u010dn\u00ed syst\u00e9my \u0159idi\u010de (Advanced Driver Assistance Systems, ADAS) a infotainment. P\u0159es stejn\u00fd link lze p\u0159en\u00e1\u0161et r\u016fzn\u00e9 protokoly, nap\u0159\u00edklad video a ethernet. To zjednodu\u0161uje infrastrukturu. Krom\u011b toho lze kombinovat n\u011bkolik datov\u00fdch tok\u016f. To zahrnuje mo\u017enost rozd\u011blit video streamy pro nap\u00e1jen\u00ed mnoha displej\u016f ve vozidle, nap\u0159\u00edklad informa\u010dn\u00edho clusteru (IC) a centr\u00e1ln\u00edho informa\u010dn\u00edho displeje (CID).<\/p>\n

Jak se GMSL dostal do vozidla?<\/h2>\n

Na za\u010d\u00e1tku pou\u017e\u00edvala spole\u010dnost GMSL st\u00edn\u011bn\u00e1 dvouvodi\u010dov\u00e1 veden\u00ed. Impedance p\u0159enosov\u00e9ho syst\u00e9mu je tedy 100 \u03a9. Koaxi\u00e1ln\u00ed veden\u00ed bylo poprv\u00e9 pou\u017eito v roce 2016 ve t\u0159\u00edd\u011b E spole\u010dnosti Daimler. Z\u00e1porn\u00e9 diferenci\u00e1ln\u00ed vstupy a v\u00fdstupy byly p\u0159ipojeny k zemi pomoc\u00ed rezistor\u016f 50 \u03a9. Koaxi\u00e1ln\u00ed kabely jsou cenov\u011b v\u00fdhodn\u011bj\u0161\u00ed a umo\u017e\u0148uj\u00ed tak\u00e9 nap\u00e1jen\u00ed perifern\u00edch kamer prost\u0159ednictv\u00edm technologie Power-over-Coax, zkr\u00e1cen\u011b PoC. Frekven\u010dn\u00ed spektrum je p\u0159itom rozd\u011bleno. \u0158\u00eddic\u00ed sign\u00e1ly maj\u00ed ni\u017e\u0161\u00ed rychlost p\u0159enosu dat a jsou p\u0159en\u00e1\u0161eny v ni\u017e\u0161\u00edm spektru. Kv\u016fli k\u00f3dov\u00e1n\u00ed 8B10B nebo 9B10B u nov\u011bj\u0161\u00edch verz\u00ed jsou data pro downlink posunuta do horn\u00edho rozsahu spektra. Modulace se prov\u00e1d\u00ed metodou Non-Return to Zero, zkr\u00e1cen\u011b NRZ, v\u010detn\u011b generace GMSL 2. Od generace GMSL 3 se pou\u017e\u00edv\u00e1 PAM4 (pulzn\u00ed amplitudov\u00e1 modulace se \u010dty\u0159mi stupni). P\u0159enosov\u00e9 rychlosti se v posledn\u00edch letech zv\u00fd\u0161ily. Generace s GMSL 3 umo\u017e\u0148uje p\u0159enosovou rychlost 12 Gbit\/s. Existuj\u00ed r\u016fzn\u00e9 \u010dipy serializ\u00e9r\u016f a deserializ\u00e9r\u016f, kter\u00e9 umo\u017e\u0148uj\u00ed r\u016fzn\u00e1 rozhran\u00ed videa a \u0159\u00eddic\u00ed rozhran\u00ed. Podporov\u00e1ny jsou MIPI CSI-2 (s C-PHY nebo D-PHY), MIPI DSI, OpenLDI, eDP a HDMI. Ne v\u0161echny \u010dipy jsou vz\u00e1jemn\u011b kompatibiln\u00ed.<\/p>\n

Bude se pou\u017e\u00edvat LVDS?<\/h2>\n

Ve skute\u010dnosti existuje n\u011bkolik variant \u010dip\u016f, z nich\u017e n\u011bkter\u00e9 pracuj\u00ed tak\u00e9 s LVDS. Portfolio SerDes zahrnuje tak\u00e9 dal\u0161\u00ed varianty s CML, HDMI nebo CMOS\/LVCMOS.<\/p>\n

Je mo\u017en\u00e9 kompenzovat vlivy kabel\u016f?<\/h2>\n

Technologie GMSL SerDes umo\u017e\u0148uje p\u0159enos na velkou vzd\u00e1lenost a\u017e 15 m. Kamery mohou b\u00fdt um\u00edst\u011bny ve vzd\u00e1lenosti 15 m od hostitelsk\u00e9ho procesoru prost\u0159ednictv\u00edm koaxi\u00e1ln\u00edho kabelu 50\u00a0\u03a9 nebo st\u00edn\u011bn\u00e9ho kroucen\u00e9ho p\u00e1ru (STP) 100\u00a0\u03a9, aby pracovaly plnou rychlost\u00ed a st\u00e1le podporovaly vysokou sn\u00edmkovou frekvenci a men\u0161\u00ed zpo\u017ed\u011bn\u00ed. Krom\u011b toho lze vy\u0161\u0161\u00ed \u00fatlum kabelu p\u0159i vy\u0161\u0161\u00edch frekvenc\u00edch kompenzovat pomoc\u00ed adaptivn\u00edho ekvaliz\u00e9ru v GMSL. Tento ekvaliz\u00e9r kabelu m\u00e1 12 kompenza\u010dn\u00edch \u00farovn\u00ed pro a\u017e 30\u00a0m koaxi\u00e1ln\u00edho a 15\u00a0m STP kabelu. Na druh\u00e9m konci je maxim\u00e1ln\u00ed d\u00e9lka kabelu pro standardn\u00ed p\u0159ipojen\u00ed kamery MIPI\u00ae CSI-2 30\u00a0cm.<\/p>\n

To by v\u00e1s tak\u00e9 mohlo zaj\u00edmat<\/h3>A\u00b2B (Automotive Audio Bus)\u00a0<\/a>ADAS<\/a>AMEC<\/a>APIX<\/a>Automotive Ethernet<\/a>Autonomn\u00ed \u0159\u00edzen\u00ed<\/a>C.A.S.E<\/a>FAKRA<\/a>FPD-Link<\/a>H-MTD<\/a>HSD<\/a>Kabelov\u00e1 konfekce<\/a>Koax<\/a>Latence<\/a>LiDAR<\/a>LVDS<\/a>Multi-Gig-Ethernet (multigigabitov\u00fd Ethernet)<\/a>On-board diagnostics (OBD)<\/a>P\u00e1te\u0159n\u00ed linky<\/a>Radar<\/a>Senzory<\/a>St\u00edn\u011bn\u00ed<\/a>V2X<\/a>WiGig<\/a><\/div>\n
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