XR68C681 Datasheet, PDF (51/75 Pages) Exar Corporation – CMOS Dual Channel UART (DUART)

XR68C681
Remote Loopback Mode
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Note: The CPU has no access to the Serial Data during Remote Loopback Mode.
Figure 22. A Block Diagram Depicting “Remote Loopback Mode” Operation
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MR2n[5] - Transmitter Request-to-Send Control
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MR2n[4] - Clear to Send Control
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