HD404669 Datasheet, PDF (64/142 Pages) Hitachi Semiconductor – Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit

HD404669 Series
Registers for Timer C Operation
By using the following registers, timer C operation modes are selected and the timer C count is read and
written.
• Timer mode register C1 (TMC1: $00D)
• Timer mode register C2 (TMC2: $014)
• Timer write register C (TWCL: $00E, TWCU: $00F)
• Timer read register C (TRCL: $00E, TRCU: $00F)
Timer mode register C1 (TMC1: $00D): Four-bit write-only register that selects the free-running/reload
timer function, and the prescaler division ratio as shown in figure 43. It is reset to $0 by MCU reset or in
stop mode.
Writing to this register is valid from the second instruction execution cycle after the execution of the
previous timer mode register C1 write instruction. Setting timer C’s initialization by writing to timer write
register C (TWCL: $00E, TWCU: $00F) must be done after a mode change becomes valid.
Timer mode register C1 (TMC1: $00D)
Bit
Initial value
Read/Write
Bit name
3
0
W
TMC13
2
0
W
TMC12
1
0
W
TMC11
0
0
W
TMC10
TMC13
0
1
Free-running/reload timer selection
Free-running timer
Reload timer
TMC12 TMC11 TMC10 Input clock period
0
0
0
2048t_cyc
1
1024t_cyc
1
0
512t_cyc
1
128t_cyc
1
0
0
32t_cyc
1
8t_cyc
1
0
4t_cyc
1
2t_cyc
Figure 43 Timer Mode Register C1 (TMC1)
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