32 lines
1,006 B
Markdown
32 lines
1,006 B
Markdown
---
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tags:
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- computer-architecture
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- micro-controllers
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---
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A serial port/device transmits data sequentially, one bit at a time over a
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single channel/data line.
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This is in contrast to parallel transmission, where there are multiple
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channels/data lines, used simultaneously.
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With serial transmission, one bit is sent after another:
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With parallel transmission, each bit of a byte travels on its own channel in
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parallel:
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Although we say a serial device transmits over a single channel, this is a
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logical distinction. The actual electrical signals will be transmitted
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physically via multiple wires.
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## Serial devices on Linux
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Most serial devices today connect via [USB](./USB_protocols_and_connectors.md).
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On Linux, `/dev/ttyUSB*` is a [device](./Devices.md) file representing the
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physical USB connection to a serial device like, for example, an
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[ESP32](./ESP_32.md) microcontroller.
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