XR88C681CP Datasheet, PDF (40/99 Pages) Exar Corporation – CMOS DUAL CHANNEL UART (DUART)

XR88C681
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Figure 16. Timing Diagram Illustrating the Sequence of Events Occurring Between the
DUART and the CPU During an Interrupt Request/Acknowledge and Servicing
Additional Things to Note About Z-Mode Operation
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Please note that it is possible to interface the 80X86
Family of microprocessors to an I-Mode DUART,
however, additional components and design complexity
would be required in order to accomplish this  
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