{"schemaVersion":1,"slug":"iec-address-dependency-a","name":"IEC address dependency (A)","kind":"symbol","abbreviation":"Am","aliases":["A dependency","address dependency notation","memory address label"],"category":"logic-signals","drawingTypes":["Schematic"],"referenceFamilies":["IEC","Manufacturer"],"summary":"Dependency label A used on memory symbols to show which word of an array the address inputs select.","description":["A dependency is used mainly on memory symbols. Address inputs are grouped, often with the binary grouping symbol, to produce internal affecting inputs A0 to An. Data inputs and outputs labelled A then act only on the selected word, so one symbol can represent an entire array.","Reading a memory symbol, start with the address grouping to see the range, then follow the A-labelled data terminals. TI's public overview shows an array of latches forming a small random-access memory using this method.","The notation does not give access time or organisation details beyond word count and width. Those are in the device data."],"readingNotes":["Find the address grouping and its range first.","Terminals labelled A act on the selected word only."],"drawingChecklist":["Show the address bus with its binary grouping.","Label affected data terminals with A.","State word count and width in the outline title."],"distinction":"M dependency selects modes, while A selects which of several identical words is accessed.","facts":[{"label":"Affecting input at 1","value":"Permits action (address selected)"},{"label":"Typical device","value":"RAM or ROM"},{"label":"Artwork scope","value":"Original educational illustration; consult the applicable standard and the selected device documentation for the exact graphic"}],"references":[{"sourceId":"s28-ti-ieee91-logic-symbols","relevance":"A (address) dependency and memory array examples."}],"related":["iec-random-access-memory","iec-read-only-memory","iec-mode-dependency-m"],"artwork":"s28-iec-address-dependency-a","publishedOn":"2026-10-28","updatedOn":"2026-10-28","provenance":"independent-public-research","symbolVariant":{"convention":"IEC","form":"Address inputs grouped to produce A affecting inputs; affected terminals labelled A","reference":"Qualifying-symbol and dependency conventions as explained in TI's public overview of IEEE Std 91-1984, which incorporates IEC 617-12 work. Independent educational drawing; not certified IEC geometry or an IEC database identifier."},"plainEnglish":{"title":"What does IEC address dependency (A) mean?","introduction":"A dependency is used mainly on memory symbols. Address inputs are grouped, often with the binary grouping symbol, to produce internal affecting inputs A0 to An. Data inputs and outputs labelled A then act only on the selected word, so one symbol can represent an entire array.","example":"Reading a memory symbol, start with the address grouping to see the range, then follow the A-labelled data terminals. TI's public overview shows an array of latches forming a small random-access memory using this method.","drawings":"The notation does not give access time or organisation details beyond word count and width. Those are in the device data.","terms":[{"name":"Terminal","meaning":"An identified point where a conductor connects."},{"name":"Signal","meaning":"Electrical information passed between devices, rather than necessarily the main power supply."},{"name":"Schematic","meaning":"A drawing showing function and connections rather than physical appearance."}],"diagram":"flow","steps":["Identify the device and form","Read the connections and state","Check the equipment reference"],"caption":"A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram.","sources":[{"label":"Overview of IEEE Standard 91-1984: explanation of logic symbols (SDYZ001A)","url":"https://www.ti.com/lit/ml/sdyz001a/sdyz001a.pdf"}],"detail":"Dependency label A used on memory symbols to show which word of an array the address inputs select. M dependency selects modes, while A selects which of several identical words is accessed.","profileId":"reviewed-symbol-20261028"},"url":"https://eloragrid.ai/symbols/iec-address-dependency-a","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/iec-address-dependency-a.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"s28-ti-ieee91-logic-symbols","title":"Overview of IEEE Standard 91-1984: explanation of logic symbols (SDYZ001A)","publisher":"Texas Instruments","url":"https://www.ti.com/lit/ml/sdyz001a/sdyz001a.pdf","type":"manufacturer","scope":"Public explanation of rectangular logic symbols, general qualifiers, input and output qualifiers, dependency notation, bistable elements and coders, consistent with IEC 617-12 work.","checkedOn":"2026-10-28","reuse":"link-only","relevance":"A (address) dependency and memory array examples."}]}