HD404849 Datasheet, PDF (53/125 Pages) Hitachi Semiconductor – 4-Bit Single-Chip Microcomputer

HD404849 Series
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
PMRA1
0
1
R2₂/SI mode selection
R2₂
SI
PMRA0
0
1
R2₃/SO mode selection
R2₃
SO
Figure 36 Port Mode Register A (PMRA)
LCD output register 3 (LOR3: $01F)
Bit
Initial value
Read/Write
Bit name
3
—
—
Not used
2
0
W
LOR32
1
0
0
—
W
—
LOR31 Not used
LOR32 R7/SEG17–SEG20 mode selection
0 R7
1 SEG17–SEG20
LOR31 R6/SEG13–SEG16 mode selection
0 R6
1 SEG13–SEG16
Figure 37 LCD Output Register 3 (LOR3)
Pull-Up MOS Transistor Control: A program-controlled pull-up MOS transistor is provided for each
input/output pin other than input-only pins D₁₀ and D₁₁. The on/off status of all these transistors is
controlled by bit 3 (MIS3) of the miscellaneous register (MIS: $00C), and the on/off status of an individual
transistor can also be controlled by the port data register (PDR) of the corresponding pin—enabling on/off
control of that pin alone (table 23 and figure 38).
The on/off status of each transistor and the peripheral function mode of each pin can be set independently.
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