ADLINK USB-1210 - Manual (Page 48)

38 Operation & Calibration
imum counting width is 32-bit. Decrease of the counter value in
Edge Separation Measurement mode is shown.
Figure 3-22: Mode 9-Edge Separation Measurement
Mode 10: PWM Output
The USB-1210 timer/counter can also simulate a PWM (Pulse
Width Modulation) output. The PWM starts to generate output fol-
lowing a GPTC_GATE edge trigger or being activated/inactivated
by the GPTC_GATE high/low logic control. By setting a varying
amount of Pulse_initial_cnt and Pulse_length_cnt, varying pulse
frequencies (Fpwm) and duty cycles (Dutypwm) can be obtained.
PWM output is shown.
Figure 3-23: Mode 10-PWM Output Following Trigger
Figure 3-24: Mode 10-PWM Output Following GATE Control
Calculation of the PWM frequency and duty cycle is as follows.
1 3 1 3 1 2 1 1 9 8 7 6
S o f t w a r e s t a r t
5 4 3 2 1 1 1 1 1 1
G a t e
C L K
A U X
C o u n t v a l u e 1 0
TIMEBASE
PWMOUT
Pulse_Initial_cnt= 0x7
Gate
Pulse_Length_cnt= 0xB
Software Start
TIMEBASE
PWMOUT
Pulse_Initial_cnt= 0x7
Gate
Pulse_Length_cnt= 0xB
Software Start