HD404054 Datasheet, PDF (58/101 Pages) Hitachi Semiconductor – HMCS400-series microcomputers designed to increase program productivity with large-capacity memory

HD404054 Series/HD404094 Series
Registers for Timer D Operation: By using the following registers, timer D operation modes are selected
and the timer D count is read and written.
Timer mode register D1 (TMD1: $010)
Timer mode register D2 (TMD2: $015)
Timer write register D (TWDL: $011, TWDU: $012)
Timer read register D (TRDL: $011, TRDU: $012)
Port mode register C (PMRC: $025)
Detection edge select register 2 (ESR2: $027)
• Timer mode register D1 (TMD1: $010): Four-bit write-only register that selects the free-
running/reload timer function, input clock source, and the prescaler division ratio as shown in figure 41.
It is reset to $0 by MCU reset.
Writing to this register is valid from the second instruction execution cycle after the execution of the
previous timer mode register D1 (TMD1: $010) write instruction. Setting timer D’s initialization by
writing to timer write register D (TWDL: $011, TWDU: $012) must be done after a mode change
becomes valid.
When selecting the input capture timer operation, select the internal clock as the input clock source.
Timer mode register D1 (TMD1: $010)
Bit
Initial value
Read/Write
Bit name
3
0
W
TMD13
2
0
W
TMD12
1
0
W
TMD11
0
0
W
TMD10
TMD13
0
1
Free-running/reload
timer selection
Free-running timer
Reload timer
TMD12 TMD11 TMD10
0
0
0
1
1
0
1
1
0
0
1
1
0
1
Input clock period and
input clock source
2048t_cyc
512t_cyc
128t_cyc
32t_cyc
8t_cyc
4t_cyc
2t_cyc
R4₀/EVND (external event input)
Figure 41 Timer Mode Register D1 (TMD1)
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