HD404849 Datasheet, PDF (78/127 Pages) Hitachi Semiconductor – 4-Bit Single-Chip Microcomputer

HD404849 Series
• Timer read register D (TRDL: $011, TRDU: $012): Read-only register consisting of a lower digit
(TRDL) and upper digit (TRDU). See figures 63 and 64. The operation of timer read register D is
basically the same as that of timer read register B (TRBL: $00A, TRBU: $00B).
When the input capture timer operation is selected and if the count of timer D is read after a trigger is
input, either the lower or upper digit can be read first.
Timer read register D (lower digit) (TRDL: $011)
Bit
Initial value
Read/Write
Bit name
3
2
1
0
Undefined Undefined Undefined Undefined
R
R
R
R
TRDL3 TRDL2 TRDL1 TRDL0
Figure 63 Timer Read Register D Lower Digit (TRDL)
Timer read register D (upper digit) (TRDU: $012)
Bit
Initial value
Read/Write
Bit name
3
2
1
0
Undefined Undefined Undefined Undefined
R
R
R
R
TRDU3 TRDU2 TRDU1 TRDU0
Figure 64 Timer Read Register D Upper Digit (TRDU)
• Port mode register C (PMRC: $025): Write-only register that selects R2₀/EVND pin function as shown
in figure 50. It is reset to $0 by MCU reset.
• Detection edge select register 2 (ESR2: $027): Write-only register that selects the detection edge of
signals input to pin EVND as shown in figure 65. It is reset to $0 by MCU reset.
76