Texas Instruments MSP430x1xx User Manual page 226

Timer_A Operation
Output Example—Timer in Up/Down Mode
The OUTx signal changes when the timer equals TACCRx in either count
direction and when the timer equals TACCR0, depending on the output mode.
An example is shown in Figure 11−14 using TACCR0 and TACCR2.
Figure 11−14.Output Example—Timer in Up/Down Mode
0FFFFh
TACCR0
TACCR2
0h
TAIFG
Note: Switching Between Output Modes
When switching between output modes, one of the OUTMODx bits should
remain set during the transition, unless switching to mode 0. Otherwise,
output glitching can occur because a NOR gate decodes output mode 0. A
safe method for switching between output modes is to use output mode 7 as
a transition state:
11-16
Timer_A
EQU2 EQU2 EQU2
EQU0 TAIFG EQU0
BIS #OUTMOD_7,&TACCTLx ; Set output mode=7
BIC #OUTMODx,&TACCTLx
Output Mode 1: Set
Output Mode 2: Toggle/Reset
Output Mode 3: Set/Reset
Output Mode 4: Toggle
Output Mode 5: Reset
Output Mode 6: Toggle/Set
Output Mode 7: Reset/Set
EQU2
Interrupt Events
; Clear unwanted bits