HD404629R Datasheet, PDF (95/157 Pages) Renesas Technology Corp – AS Microcomputer Incorporating a DTMF Generator Circuit

HD404629R Series
Serial data register (upper digit) (SRU: $007)
Bit
Initial value
Read/Write
Bit name
3
2
1
0
Undefined Undefined Undefined Undefined
R/W
R/W
R/W
R/W
SR7
SR6
SR5
SR4
Figure 77 Serial Data Register (SRU)
Transmit clock
Serial output
data
1
2
3
4
5
6
7
8
LSB
MSB
Serial input data
latch timing
Figure 78 Serial Interface Output Timing
Port Mode Register A (PMRA: $004): This register has the following functions (figure 79).
 R2₂/SI pin function selection
 R2₃/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
PMRA1
0
1
R2₂/SI mode selection
R2₂
SI
PMRA0
0
1
R2₃/SO mode selection
R2₃
SO
Figure 79 Port Mode Register A (PMRA)
93