tmp89fm42 TOSHIBA Semiconductor CORPORATION, tmp89fm42 Datasheet - Page 172

• Manufacturer Part Number: tmp89fm42
• Description: 8 Bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

13.4 Timer Function
13. 16-bit Timer Counter (TCA)
RA001
13.4.5 Pulse width measurement mode
13.4.5.1 Setting
13.4.5.2 Operation
to the TCA0 pin and measures the input pulse width based on the internal clock.
In the pulse width measurement mode, the up counter starts counting at the rising/falling edge(s) of the input
ment mode. Select the source clock at TA0MOD<TA0CK>.
TA0MOD<TA0TED> to "0" selects the rising edge, and setting it to "1" selects the falling edge as a trig-
ger to start the capture.
TA0MOD<TA0MCAP>. Setting TA0MOD<TA0MCAP> to "0" selects the double-edge capture. Setting
TA0MOD<TA0MCAP> to "1" selects the single-edge capture.
interrupt control TA0CR<TA0OVE>. Setting TA0OVE to "1" makes an INTTA0 interrupt request occur
in case of an overflow. Setting TA0OVE to "0" makes no INTTA0 interrupt request occur in case of an
overflow.
in port settings.
TA0MOD and TA0CR<TA0OVE> is disabled. Be sure to complete the required mode settings before
starting the timer.
counter increments according to the selected source clock. Subsequently, when the edge opposite to the
selected edge is detected, the up counter value is captured into TA0DRB, an INTTA0 interrupt request is
generated, and TA0SR<TA0CPFB> is set to "1". Depending on the TA0MOD<TA0MCAP> setting, the
operation differs as follows:
this time, an INTTA0 interrupt request occurs if the overflow interrupt control TA0CR<TA0OVE> is set
to "1".
(TA0SR<TA0OVF>) are cleared to "0" automatically when TA0SR is read.
Setting the operation mode selection TA0MOD<TA0M> to "110" activates the pulse width measure-
Select the trigger edge at the trigger edge input selection TA0MOD<TA0TED>. Setting
The operation after capturing is determined by the pulse width measurement mode control
The operation to be executed in case of an overflow of the up counter can be selected at the overflow
Note that this mode uses the TA0 input pin, and the TCA0 pin must be set to the input mode beforehand
The operation is started by setting TA0CR<TA0S> to "1". After the timer is started, writing to
After the timer is started, when the selected trigger edge (start edge) is input to the TCA0 pin, the up
When the up counter overflows during capturing, the overflow flag TA0SR<TA0OVF> is set to "1". At
The
• Double-edge capture (When TA0MOD<TA0MCAP> is "0")
• Single-edge capture (When TA0MOD<TA0MCAP> is "1")
capture
Subsequently, when the selected trigger edge is input, the up counter value is captured into
TA0DRA, an INTTA0 interrupt request is generated, and TA0SR<TA0CPFA> is set to "1". At
this time, the up counter is cleared to "0000H".
selected edge is detected. Subsequently, when the start edge is input, the up counter restarts
increment.
The up counter continues counting up after the edge opposite to the selected edge is detected.
The up counter stops counting up and is cleared to "0000H" when the edge opposite to the
completion
flags
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(TA0SR<TA0CPFA,
TA0CPFB>
and
the
overflow
TMP89FM42
flag