HD404459 Datasheet, PDF (83/122 Pages) Renesas Technology Corp – 4-bit HMCS400-series microcomputers

HD404459 Series
Serial Interface
The MCU has a serial interface (figure 67). The serial interface serially transfers or receives 8-bit data, and
includes the following features.
• Multiple transmit clock sources
 External clock
 Internal prescaler output clock
 System clock
• Output level control in idle states
Five registers, an octal counter, and a multiplexer are also configured for the serial interface as follows.
 Serial data register (SRL: $006, SRU: $007)
 Serial mode register A (SMRA: $005)
 Serial mode register B (SMRB: $028)
 Port mode register A (PMRA: $004)
 Miscellaneous register (MIS: $00C)
 Octal counter (OC)
 Selector
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