HCTL-1100 Datasheet, PDF (21/40 Pages) Agilent(Hewlett-Packard) – General Purpose Motion Control ICs

PWM Motor Command Register
(R09H)
The PWM port outputs the motor
command as a pulse width
modulated signal with the correct
sign of polarity. The PWM port
consists of the Pulse and Sign
pins and R09H.
The PWM signal at the Pulse pin
has a frequency of External
Clock/100 and the duty cycle is
resolved into the 100 clocks. (For
example, a 2 MHz clock gives a
20 KHz PWM frequency.)
The Sign pin gives the polarity of
the command. Low output on Sign
pin is positive polarity.
The 2’s-complement contents of
R09H determine the duty cycle
and polarity of the PWM
command. For example, D8H
(–40D) gives a 40% duty cycle
signal at the Pulse pin and forces
the Sign pin high. Data outside
the 64H (+100D) to 9CH
(–100D) linear range gives 100%
duty cycle. R09H can be read and
written to. However, the user
should only write to R09H when
the controller is in the Initiali-
zation/Idle mode.
Figure 5 shows the PWM output
versus the internal motor
command.
Figure 4. Motor Command Port Output.
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