UART

Lo UART o Universal Asynchronous Receiver-Transmitter (ricevitore-trasmettitore asincrono universale) è un dispositivo hardware, di uso generale o dedicato, che converte flussi di bit di dati da un formato parallelo a un formato seriale asincrono o viceversa.

Gli USART (Universal Synchronous-Asynchronous Receiver/Transmitter), hanno il compito di gestire le comunicazioni delle interfacce seriali RS-232. Costituiscono un'evoluzione degli UART, come si evince dal nome stesso, in grado di gestire anche trasmissioni seriali sincrone. In un secondo tempo furono dotati di un buffer interno di tipo FIFO.

Storia

Exar Corporation 16550

Il primo USART montato sul PC IBM fu l'Intel 8251A denominato Programmable Communication Interface, un'USART ad un solo canale. Mentre il 8250 UART della National Semiconductor fu installato nella prima gamma di IBM PC per gestire la porta seriale RS-232 e successivamente installato su una vasta gamma di dispositivi dell'epoca.[1] Il 8250 aveva una velocità massima (programmable) di 9600 bps. Nella linea IBM Personal Computer/AT fu sostituito dal migliorato 16450.

A seguire fu rilasciato il 16550 UART della National Semiconductor introdotto inizialmente nella gamma IBM PS/2 e poteva andare ad una velocità massima di 115200 bps. Per ovviare alla gestione degli interrupt carattere per carattere, rallentando la CPU, il 16550 offriva un buffer FIFO a 16-byte. Sia l'interfaccia hardware che software del 16550 sono retro-compatibili con il 16450 UART. La sua ultima revisione è la 16550D rilasciata nel 1995.[2]

A partire dagli anni 2000, la maggior parte dei produttori di computer IBM compatibili ha iniziato a rimuovere le porte RS-232 esterne in favore di connessioni più veloci e versatili come l'USB. Per gli utenti che necessitano ancora di porte seriali RS-232, vengono comunemente utilizzati adattatori USB-UART esterni.

Descrizione

Ogni famiglia di microprocessori ha la sua UART/USART dedicata. Nei microcontrollori, quando disponibile, questa funzione è interna agli stessi.

La famiglia Z80 chiamava questi componenti "Serial Input Output": SIO0, SIO1, SIO2 che erano degli USART a 2 canali, e il SIO9 che aveva un solo canale. Della famiglia faceva parte anche un componente asincrono chiamato DART (Dual Asynchronous Receiver Trasmitter).

Nei personal computer IBM compatibili le funzioni UART sono espletate da un circuito integrato disegnato per implementare l'interfaccia elettrica per la comunicazione seriale, questo è spesso usato per implementare la porta seriale dove è spesso connesso ad un RS-232 per modem, mouse e stampanti.

Note

  1. ^ 8250 UART Information, su www.techedge.com.au. URL consultato il 20 ottobre 2022.
  2. ^ PC16550D datasheet (PDF), su national.com. URL consultato il 20 ottobre 2022 (archiviato dall'url originale il 13 giugno 2008).

Voci correlate

Altri progetti

Collegamenti esterni

  Portale Informatica: accedi alle voci di Wikipedia che trattano di informatica

Read other articles:

Hari Kemenangan (Turki)

Hari KemenanganPrajurit Angkatan Bersenjata Turki selama parade Hari Kemenangan, 30 Agustus 2007.Nama resmiZafer Bayramıcode: tr is deprecated   (Turkish)Nama lainHari Angkatan Bersenjata TurkiTiga Puluh AgustusDirayakan oleh Turkey Siprus UtaraJenisNasionalMaknaHari pada tahun 1922 Pertempuran Dumlupınar dimenangkan oleh tentara TurkiPerayaanParade militer, aerobatik demonstrasi, konser, acara di sekolah militerTanggal30 AgustusFrekuensitahunan Hari Kemenangan (Turki: Z...

 

Kition

Kition𐤊𐤕‎ atau 𐤊𐤕𐤉‎Κιτιονabad ke-13 SM–342 SM[1]Letak Kition (diarsir warna merah)Ibu kotaKitionBahasa yang umum digunakanYunani Arkadiasiprus[2] dan Fenisia[2]Agama Agama Yunani Kuno dan KanaanPemerintahanKerajaanEra SejarahZaman Klasik• Didirikan abad ke-13 SM• Dibubarkan 342 SM[1] Mata uangStater, ObolosSekarang bagian dariSiprus Sunting kotak info • Lihat • BicaraBantuan penggunaan templat ...

 

Chitra Visweswaran

Indian dancer This biography of a living person needs additional citations for verification. Please help by adding reliable sources. Contentious material about living persons that is unsourced or poorly sourced must be removed immediately from the article and its talk page, especially if potentially libelous.Find sources: Chitra Visweswaran – news · newspapers · books · scholar · JSTOR (March 2015) (Learn how and when to remove this template message) C...

Dragon's teeth (mythology)

Aspect of Greek mythology For other uses, see Dragon's teeth (disambiguation). Cadmus Sowing the Dragon's Teeth, by Maxfield Parrish, 1908 In Greek myth, dragon's teeth (Greek: ὀδόντες (τοῦ) δράκοντος, odontes (tou) drakontos) feature prominently in the legends of the Phoenician prince Cadmus and in Jason's quest for the Golden Fleece. In each case, the dragons are present and breathe fire. Their teeth, once planted, would grow into fully armed warriors. Myths Cadmus and ...

 

Henry Stuart, Duke of Gloucester

Duke of Gloucester Henry StuartDuke of GloucesterPortrait by Jan Boeckhorst, c. 1659[1]Born8 July 1640Oatlands Palace, Surrey, EnglandDied13 September 1660(1660-09-13) (aged 20)Palace of Whitehall, London, EnglandBurial21 September 1660Westminster Abbey, LondonHouseStuartFatherCharles I of EnglandMotherHenrietta Maria of France Henry Stuart, Duke of Gloucester (8 July 1640 – 13 September 1660)[a] was the youngest son of Charles I, King of England, Scotland...

 

Scientology and celebrities

Church of Scientology recruiting Part of a series onScientology General Scientology Dianetics Timeline History L. Ron Hubbard Publications Glossary Beliefs and practices Thetan Auditing Bridge to Total Freedom OT Xenu Ethics and justice Church of Scientology Officials and staff Sea Org David Miscavige Controversies Litigation Status by country Suppressive person Disconnection Fair game RPF The Hole Office of Special Affairs Guardian's Office War on psychiatry More Recruiting and retaining Sci...

Saint-Evroult-Notre-Dame-du-Bois

Saint-Évroult-Notre-Dame-du-BoisSaint-Évroult-Notre-Dame-du-Bois Lokasi di Region Normandia Saint-Évroult-Notre-Dame-du-Bois Koordinat: 48°47′32″N 0°27′45″E / 48.7922°N 0.4625°E / 48.7922; 0.4625NegaraPrancisRegionNormandiaDepartemenOrneArondisemenArgentanKantonFerté-FrênelAntarkomuneCanton of la Ferté-FrênelPemerintahan • Wali kota (2008–2014) Gilles SimonLuas • Land134,47 km2 (1,331 sq mi) • Popu...

 

الجمعية السعودية للإعاقة السمعية

هذه المقالة يتيمة إذ تصل إليها مقالات أخرى قليلة جدًا. فضلًا، ساعد بإضافة وصلة إليها في مقالات متعلقة بها. (يناير 2020) الجمعية السعودية للإعاقة السمعية البلد السعودية  المقر الرئيسي الرياض،  السعودية تاريخ التأسيس 1421هـ(2004م) النوع منظمة خيرية الوضع القانوني نشط الاهتما�...

 

Hokuto, Yamanashi

Balai Kota Hokuto Hokuto (北杜市, Hokuto-shi) adalah sebuah kota yang terletak di Prefektur Yamanashi, Jepang. Pada 31 Mei 2019, kota ini memiliki perkiraan populasi 46.888 di 21.332 rumah tangga, dan kepadatan penduduk 78 orang per km2. Luas total kota ini adalah 602,48 kilometer persegi (232,62 sq mi). Geografi Hokuto terletak di barat laut Prefektur Yamanashi. Sebagian besar wilayah kota adalah dataran tinggi yang ditinggikan dan berhutan, dengan sepertiga kota terletak di lereng tengga...

Breuilaufa

Peta infrastruktur dan tata guna lahan di Komune Breuilaufa.  = Kawasan perkotaan  = Lahan subur  = Padang rumput  = Lahan pertanaman campuran  = Hutan  = Vegetasi perdu  = Lahan basah  = Anak sungaiBreuilaufa merupakan sebuah komune di departemen Haute-Vienne di Prancis. Lihat pula Komune di departemen Haute-Vienne Referensi INSEE lbsKomune di departemen Haute-Vienne Aixe-sur-Vienne Ambazac Arnac-la-Poste Augne Aureil Azat-le-Ris Balledent La Bazeuge B...

 

Winsted, Connecticut

CDP in Connecticut, United States Census-designated place in Connecticut, United StatesWinsted, ConnecticutCensus-designated placeCity of WinstedWest End Commercial DistrictNickname: Laurel City Litchfield County and Connecticut Northwest Hills Planning Region and ConnecticutShow WinstedShow ConnecticutShow the United StatesCoordinates: 41°55′15″N 73°3′33″W / 41.92083°N 73.05917°W / 41.92083; -73.05917CountryUnited StatesStateConnecticutCount...

 

Ливанская кухня

Фалафель Табули Фаттуш Ливанская кухня, (араб. المأكولات اللبنانية‎) — национальная кухня Ливана, типичная средиземноморская кухня. Для неё характерны разнообразие вегетарианских блюд, использование приправ и таких продуктов как бобовые (боб обыкновенный, нут), св...

Jailangkung 2

Untuk kegunaan lain, lihat Jailangkung (disambiguasi). Jailangkung 2Poster resmiSutradara Jose Poernomo Rizal Mantovani Produser Sukhdev Singh Wicky V. Olindo Robert Ronny Ditulis oleh Ve Handoyo Baskoro Adi Wuryanto Pemeran Jefri Nichol Amanda Rawles Hannah Al Rashid Lukman Sardi Gabriella Quinlyn Naufal Samudra Dania Michelle Deddy Sutomo Ratna Riantiarno Penata musikJoseph S. DjafarSinematograferJose PoernomoPenyuntingWawan I. WibowoPerusahaanproduksi Sky Media Legacy Pictures Distri...

 

美國的逃亡奴隸

此條目需要擴充。 (2017年4月24日)请協助改善这篇條目，更進一步的信息可能會在討論頁或扩充请求中找到。请在擴充條目後將此模板移除。 奴隸逃亡、追尋自由的現象與奴隸制本身同樣古老。在歷史上的美國奴隸制度中，逃亡奴隸（英語：fugitive slaves，或稱runaway slaves）是指未經奴隸主允許便擅自離開的奴隸。一般來説，他們的目的地會是立法禁止蓄奴的州或領地（包括加�...

 

Pesikta Rabbati

Not to be confused with Pesikta de-Rav Kahana. Rabbinic literatureTalmud Readers by Adolf Behrman Talmudic literature Tannaitic Mishnah Tosefta Amoraic (Gemara) Jerusalem Talmud Babylonian Talmud Later Minor Tractates Halakhic Midrash Exodus Mekhilta of Rabbi Ishmael Mekhilta of Rabbi Shimon bar Yochai Leviticus Sifra (Torat Kohanim) Numbers and Deuteronomy Sifre Sifrei Zutta on Numbers (Mekhilta le-Sefer Devarim) Aggadic Midrash Tannaitic Seder Olam Rabbah Alphabet of Rabbi Akiva Baraita of ...

Alpha Ethniki 1987-1988

Alpha Ethniki 1987-1988Α΄ Εθνική ποδοσφαίρου ανδρών 1987-1988 Competizione Alpha Ethniki Sport Calcio Edizione 52ª Date dal 6 settembre 1987al 15 maggio 1988 Luogo  Grecia Partecipanti 16 Formula Girone all'italiana A/R Risultati Vincitore Larissa(1º titolo) Retrocessioni GAS VeriaPanserraïkosPanachaïkī Statistiche Miglior marcatore Henrik Nielsen (21) Incontri disputati 240 Gol segnati 602 (2,51 per incontro) Cronologia della competizione...

 

Anson Rogers Graves

American Episcopal bishop The Right ReverendAnson Rogers GravesWestern NebraskaProvinceThe Episcopal Church DioceseWestern NebraskaOrdersOrdinationJune 4, 1871ConsecrationJanuary 1, 1890Personal detailsBorn(1842-01-13)January 13, 1842Wells, VermontDiedDecember 30, 1931(1931-12-30) (aged 89)La Mesa, CaliforniaSignature Anson Rogers Graves (April 13, 1842 – December 30, 1931) was the first bishop of the Missionary District of Western Nebraska in The Episcopal Church.[1] Biography...

 

Subsumption architecture

Subsumption architecture is a reactive robotic architecture heavily associated with behavior-based robotics which was very popular in the 1980s and 90s. The term was introduced by Rodney Brooks and colleagues in 1986.[1][2][3] Subsumption has been widely influential in autonomous robotics and elsewhere in real-time AI. Overview Subsumption architecture is a control architecture that was proposed in opposition to traditional symbolic AI. Instead of guiding behavior by s...

Legión romana

Este artículo o sección tiene referencias, pero necesita más para complementar su verificabilidad. Busca fuentes: «Legión romana» – noticias · libros · académico · imágenesEste aviso fue puesto el 26 de agosto de 2022. Unos actores de Pram (Austria) representando el avance de una legión romana en posición de ataque. La legión romana (del latín legio, derivado de legere, recoger, juntar, seleccionar) era la unidad militar de infantería básica de la antigu...

 

Culture jamming

Form of protest to subvert media culture This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these messages) This article may be too technical for most readers to understand. Please help improve it to make it understandable to non-experts, without removing the technical details. (April 2020) (Learn how and when to remove this message) This article is written like a personal reflection, personal essay, or argumentativ...