HD404369 Datasheet, PDF (69/115 Pages) Hitachi Semiconductor – 4-bit HMCS400-Series microcomputer

HD404369 Series
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 54 Timer Read Register C Lower Digit (TRCL)
Timer read register C (upper digit) (TRCU: $00F)
Bit
Initial value
Read/Write
Bit name
3
2
1
0
Undefined Undefined Undefined Undefined
R
R
R
R
TRCU3 TRCU2 TRCU1 TRCU0
Figure 55 Timer Read Register C Upper Digit (TRCU)
Notes on Use
When using the timer output as PWM output, note the following point. From the update of the timer write
register until the occurrence of the overflow interrupt, the PWM output differs from the period and duty
settings, as shown in table 26. The PWM output should therefore not be used until after the overflow
interrupt following the update of the timer write register. After the overflow, the PWM output will have the
set period and duty cycle.
In this case, the lower digit (TWCL) must be written to first, bit writing only to the lower digit does not
change the timer C value. Timer C is changed to the value in timer write register B at the same time the
upper digit (TWCU) is written to.
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