Datasheet

Second
Capture
Taken
COV = 1
Capture
Taken
No
Capture
Taken
Read
Taken
Capture
Clear Bit COV
in Register TACCTLx
Idle
Idle
Capture
Capture Read and No Capture
Capture
Capture ReadCapture
Capture
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Figure 12-11. Capture Cycle
12.2.4.1 Capture Initiated by Software
Captures can be initiated by software. The CMx bits can be set for capture on both edges. Software then
sets CCIS1 = 1 and toggles bit CCIS0 to switch the capture signal between V
CC
and GND, initiating a
capture each time CCIS0 changes state:
MOV #CAP+SCS+CCIS1+CM_3,&TACCTLx ; Setup TACCTLx
XOR #CCIS0,&TACCTLx ; TACCTLx = TAR
12.2.4.2 Compare Mode
The compare mode is selected when CAP = 0. The compare mode is used to generate PWM output
signals or interrupts at specific time intervals. When TAR counts to the value in a TACCRx:
• Interrupt flag CCIFG is set
• Internal signal EQUx = 1
• EQUx affects the output according to the output mode
• The input signal CCI is latched into SCCI
12.2.5 Output Unit
Each capture/compare block contains an output unit. The output unit is used to generate output signals
such as PWM signals. Each output unit has eight operating modes that generate signals based on the
EQU0 and EQUx signals.
12.2.5.1 Output Modes
The output modes are defined by the OUTMODx bits and are described in Table 12-2. The OUTx signal is
changed with the rising edge of the timer clock for all modes except mode 0. Output modes 2, 3, 6, and 7
are not useful for output unit 0, because EQUx = EQU0.
363
SLAU144J–December 2004–Revised July 2013 Timer_A
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