
CHAPTER 6 16-BIT TIMER
User’s Manual U15075EJ1V0UM00
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6.4.2 Operation as timer output
Timer outputs are repeatedly generated at the count value preset in 16-bit compare register 90 (CR90) based on
the intervals of the value set in TCL901 and TCL900.
To operate the 16-bit timer as a timer output, the following settings are required.
Set P26 to output mode (PM26 = 0).
Reset output latch of P26 to 0.
Set the count value in CR90.
Set 16-bit timer mode control register 90 (TMC90) as shown in Figure 6-7.
Figure 6-7. Settings of 16-Bit Timer Mode Control Register 90 for Timer Output Operation
0/1
0/1
0/1
1
0
0/1
1
TOD90 TOF90
CPT901 CPT900
TOC90
TCL901 TCL900
TOE90
TMC90
Setting of count clock (see
Table 6-2
)
Inverse enable of timer output data
TO90 output enable
Caution
If both the CPT901 flag and CPT900 flag are set to 0, the capture operation is prohibited.
When the count value of 16-bit timer counter 90 (TM90) matches the value set in CR90, the output status of the
TO90/P26 pin is inverted. This enables timer output. At that time, TM90 counting continues and an interrupt request
signal (INTTM90) is generated.
Figure 6-8 shows the timing of timer output (see Table 6-2 for the interval time of the 16-bit timer).
Figure 6-8. Timer Output Timing
Count clock
TM90 count value
CR90
INTTM90
TO90
Note
TOF90
0000H
0001H
N
FFFFH
0000H
0001H
N
FFFFH
N
N
N
N
N
Interrupt
acknowledgement
Interrupt
acknowledgement
Overflow flag set
t
Note
The initial value of TO90 becomes low level when output is enabled (TOE90 = 1).
Remark
N = 0000H to FFFFH