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13. 16-bit Timer Counter (TCA)
13.4 Timer Function
TMP89FM42
RA001
13.4.5 Pulse width measurement mode
In the pulse width measurement mode, the up counter starts counting at the rising/falling edge(s) of the input
to the TCA0 pin and measures the input pulse width based on the internal clock.
13.4.5.1 Setting
Setting the operation mode selection TA0MOD<TA0M> to "110" activates the pulse width measure-
ment mode. Select the source clock at TA0MOD<TA0CK>.
Select the trigger edge at the trigger edge input selection TA0MOD<TA0TED>. Setting
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.
The operation after capturing is determined by the pulse width measurement mode control
TA0MOD<TA0MCAP>. Setting TA0MOD<TA0MCAP> to "0" selects the double-edge capture. Setting
TA0MOD<TA0MCAP> to "1" selects the single-edge capture.
The operation to be executed in case of an overflow of the up counter can be selected at the overflow
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.
Note that this mode uses the TA0 input pin, and the TCA0 pin must be set to the input mode beforehand
in port settings.
The operation is started by setting TA0CR<TA0S> to "1". After the timer is started, writing to
TA0MOD and TA0CR<TA0OVE> is disabled. Be sure to complete the required mode settings before
starting the timer.
13.4.5.2 Operation
After the timer is started, when the selected trigger edge (start edge) is input to the TCA0 pin, the up
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:
• Double-edge capture (When TA0MOD<TA0MCAP> is "0")
The up counter continues counting up after the edge opposite to the selected edge is detected.
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".
• Single-edge capture (When TA0MOD<TA0MCAP> is "1")
The up counter stops counting up and is cleared to "0000H" when the edge opposite to the
selected edge is detected. Subsequently, when the start edge is input, the up counter restarts
increment.
When the up counter overflows during capturing, the overflow flag TA0SR<TA0OVF> is set to "1". At
this time, an INTTA0 interrupt request occurs if the overflow interrupt control TA0CR<TA0OVE> is set
to "1".
The capture completion flags (TA0SR<TA0CPFA, TA0CPFB> and the overflow flag
(TA0SR<TA0OVF>) are cleared to "0" automatically when TA0SR is read.
Summary of Contents for TLCS-870/C1 Series
Page 1: ...8 Bit Microcontroller TLCS 870 C1 Series TMP89FM42 查询TMP89FM42供应商 捷多邦 专业PCB打样工厂 24小时加急出货 ...
Page 3: ...Revision History Date Revision 2007 10 25 1 First Release 2007 11 3 2 Contents Revised ...
Page 4: ......
Page 14: ......
Page 18: ...1 3 Block Diagram TMP89FM42 1 3 Block Diagram Figure 1 2 Block Diagram ...
Page 22: ...1 4 Pin Names and Functions TMP89FM42 ...
Page 60: ...2 CPU Core 2 5 Revision History TMP89FM42 ...
Page 76: ...3 Interrupt Control Circuit 3 8 Revision History TMP89FM42 ...
Page 86: ...4 External Interrupt control circuit 4 3 Function TMP89FM42 ...
Page 102: ...7 Voltage Detection Circuit 7 5 Revision History TMP89FM42 ...
Page 126: ...8 I O Ports 8 3 I O Port Registers TMP89FM42 Note 2 i 0 to 1 ...
Page 136: ...8 I O Ports 8 5 Revision History TMP89FM42 ...
Page 142: ...9 Special Function Registers 9 3 SFR3 0x0E40 to 0x0EFF TMP89FM42 ...
Page 146: ...10 Low Power Consumption Function for Peripherals TMP89FM42 ...
Page 149: ...TMP89FM42 11 3 Revision History Rev Description RA001 Deleted SLEEP2 description ...
Page 150: ...11 Divider Output DVO 11 3 Revision History TMP89FM42 ...
Page 220: ...15 Real Time Clock RTC 15 4 Real Time Clock Operation TMP89FM42 ...
Page 250: ...16 Asynchronous Serial Interface UART 16 15 Revision History TMP89FM42 ...
Page 302: ...18 Serial Bus Interface SBI 18 7 Revision History TMP89FM42 ...
Page 338: ...21 Flash Memory 21 4 Toggle Bit D6 TMP89FM42 ...
Page 384: ...22 Serial PROM Mode 22 15 Revision History TMP89FM42 ...
Page 388: ...24 Input Output Circuit 24 1 Control Pins TMP89FM42 ...
Page 404: ...25 Electrical Characteristics 25 11 Revision History TMP89FM42 ...
Page 406: ...26 Package Dimensions TMP89FM42 ...
Page 408: ......