Maxim Integrated MAX31782 - Manual (Page 110)

MaximIntegrated 12-8
MAX31782 User’s Guide
Revision 0; 8/11
12.1.5.1UpCountPWMOutputMode
When operating in PWM output mode and configured for up count (DCEN = 0), the value in TB0V is incremented until it
reaches the reload value, TB0R . At this point, TB0V is reloaded with 0000h, the TFB flag is set (which can generate an
interrupt if enabled), and counting continues .
Figure 12-6 illustrates the PWM waveforms when the Timer B is operating
in up count PWM output mode . The period of the PWM waveform is set by the value in the TB0R register . The set and
reset modes provide similar functionality . The formulas for period and duty cycle are:
PWM PERIOD = (TB0R + 1) × TIMER B CLOCK PERIOD
Duty Cycle in Set Mode =
TB0R TB0C
TB0R 1
−
+
Duty Cycle in Reset Mode =
TB0C
TB0R 1 +
The toggle mode generates a 50% duty-cycle waveform if the TB0C register remains fixed with the Timer B running .
The period of the waveform is:
PERIOD = 2 × (TB0R + 1) × TIMER B CLOCK PERIOD
Figure 12-6. TBB Pin Waveform in Up Count PWM Output Mode
TB0C > TB0R
TB0C < TB0R
0000
TB0V
SET MODE
RESET MODE
TOGGLE MODE
SET MODE
RESET MODE
TOGGLE MODE
TB0R
TB0C < TB0R
TB0C > TB0R