0 0 01 1 11 12 2 22 23 3 33 34 4 4TOF bitset TOF bit set TOF bitperiod of counting = 2 x MOD x period of timer module counter clockMOD = 0x0004period of timer module counter clockTimer module counterFigure 29-4. Example of up-down counting29.5.3.3 Counter ResetAny write to CNT resets the TPM counter and the channel outputs to their initial values(except for channels in output compare mode).29.5.3.4 Global time base (GTB)The global time base (GTB) is a TPM function that allows multiple TPM modules toshare the same timebase. When the global time base is enabled (CONF[GTBEEN] = 1),the local TPM channels use the counter value, counter enable and overflow indicationfrom the TPM generating the global time base. If the local TPM counter is not generatingthe global time base, then it can be used as an independent counter or pulse accumulator.The local TPM counter can also be configured to synchronize to the global time base, byconfiguring (GTBSYNC = 1). When synchronized to the global time base, the localcounter will use the counter enable and counter overflow indication from the TPMgenerating the global time base. This enables multiple TPM to be configured with thesame phase, but with different periods (although the global time base must be configuredwith the longest period).29.5.3.5 Counter triggerThe TPM counter can be configured to start, stop or reset in response to a hardwaretrigger input. The trigger input is synchronized to the asynchronous counter clock, sothere is a 3 counter clock delay between the trigger assertion and the counter responding.Chapter 29 Timer/PWM Module (TPM)KL27 Sub-Family Reference Manual , Rev. 5, 01/2016Freescale Semiconductor, Inc. 477
