ST ST10F276E, User Manual, Page: 362 / 564

XBUS pulse width modulation module UM0404
362/564 DocID13284 Rev 2
Figure 155. Operation and output waveform in burst mode
18.1.4 Single shot mode
Single shot mode is selected by setting the respective bit PSx in register XPWMCON1 to ‘1’.
This mode is available for XPWM channels 2 and 3.
In this mode the timer XPTx of the respective XPWM channel is started via software and is
counting up until it reaches the value in the associated period shadow register. Upon the
next count pulse the timer is cleared to 0000h and stopped via hardware, (the respective
PTRx bit is cleared). The PWM output signal is switched to high level when the timer
contents are equal to or greater than the contents of the pulse width shadow register. The
signal is switched back to low level when the respective timer is cleared, because it is below
the pulse width shadow register.
Thus starting a XPWM timer in single shot mode produces one single pulse on the
respective port pin, provided that the pulse width value is between 0000h and the period
value. In order to generate a further pulse, the timer has to be started again via software by
setting bit PTRx (see
Figure 149 ).
XPP0
Period
Value
XPT0
Count
Value
Channel 0
XPP1
XPT1
Channel 0
Channel 1
Resulting
Output
XPOUT0