HD404459 Datasheet, PDF (95/122 Pages) Renesas Technology Corp – 4-bit HMCS400-series microcomputers

HD404459 Series
Port Mode Register A (PMRA: $004): This register has the following functions (figure 76).
• R4₂/SI pin function selection
• R4₃/SO pin function selection
Port mode register A (PMRA: $004) is a 2-bit write-only register, and is reset to $0 by MCU reset.
Port mode register A (PMRA: $004)
Bit
Initial value
Read/Write
Bit name
3
2
1
0
—
—
0
0
—
—
W
W
Not used Not used PMRA1 PMRA0
PMRA0
0
1
R4₃/SO mode selection
R4₃
SO
PMRA1
0
1
R4₂/SI mode selection
R4₂
SI
Figure 76 Port Mode Register A (PMRA)
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