HD404669 Datasheet, PDF (66/142 Pages) Hitachi Semiconductor – Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit

HD404669 Series
Timer write register C (lower digit) (TWCL: $00E)
Bit
Initial value
Read/Write
Bit name
3
0
W
TWCL3
2
0
W
TWCL2
1
0
W
TWCL1
0
0
W
TWCL0
Figure 45 Timer Write Register C Lower Digit (TWCL)
Timer write register C (upper digit) (TWCU: $00F)
Bit
Initial value
Read/Write
Bit name
3
2
1
0
Undefined Undefined Undefined Undefined
W
W
W
W
TWCU3 TWCU2 TWCU1 TWCU0
Figure 46 Timer Write Register C Upper Digit (TWCU)
Timer read register C (TRCL: $00E, TRCU: $00F): Timer read register C (TRCL: $00E, TRCU: $00F)
is a read-only register composed of a lower digit (TRCL: $00E), and an upper digit (TRCU: $00F) from
which the value of the upper digit of timer C is read directly.
First, read the upper digit (TRCU) of timer read register C. The current value of the timer C upper digit is
read and, at the same time, the value of the timer C lower digit is latched in the lower digit (TRCL) of timer
read register C. The timer C value is obtained when the upper digit (TRCU) of timer read register C is read
by reading the lower digit (TRCL) of timer read register C.
Timer read register C (lower digit) (TRCL: $00E)
Bit
Initial value
Read/Write
Bit name
3
2
1
0
Undefined Undefined Undefined Undefined
R
R
R
R
TRCL3 TRCL2 TRCL1 TRCL0
Figure 47 Timer Read Register C Lower Digit (TRCL)
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