LM3S9B81 Datasheet, PDF (434/1155 Pages) Texas Instruments – Stellaris® LM3S9B81 Microcontroller

General-Purpose Timers
Figure 11-4. 16-Bit PWM Mode Example
Count
GPTMTnR=GPTMnMR
0xC350
GPTMTnR=GPTMnMR
0x411A
TnEN set
Output
Signal
TnPWML = 0
TnPWML = 1
Time
11.3.3.5
Wait-for-Trigger Mode
The Wait-for-Trigger mode allows daisy chaining of the timer modules such that once configured,
a single timer can initiate mulitple timing events using the Timer triggers. Wait-for-Trigger mode is
enabled by setting the TnWOT bit in the GPTMTnMR register. When the TnWOT bit is set, Timer N+1
does not begin counting until the timer in the previous position in the daisy chain (Timer N) reaches
its time-out event. The daisy chain is configured such that GPTM1 always follows GPTM0, GPTM2
follows GPTM1, and so on. If Timer A is in 32-bit mode (controlled by the GPTMCFG bit in the
GPTMCFG register), it triggers Timer A in the next module. If Timer A is in 16-bit mode, it triggers
Timer B in the same module, and Timer B triggers Timer A in the next module. Care must be taken
that the TAWOT bit is never set in GPTM0. Figure 11-5 on page 434 shows how the GPTMCFG bit
affects the daisy chain. This function is valid for both one-shot and periodic modes.
Figure 11-5. Timer Daisy Chain
GP Timer N+1
10
GPTMCFG
Timer B
Timer A
Timer B ADC Trigger
Timer A ADC Trigger
GP Timer N
10
GPTMCFG
Timer B
Timer A
Timer B ADC Trigger
Timer A ADC Trigger
434
June 29, 2010
Texas Instruments-Advance Information