Notes On Using Stepper Motor Controller - Fujitsu MB96300 series Hardware Manual

CHAPTER 27 STEPPER MOTOR CONTROLLER
27.8

Notes on Using Stepper Motor Controller

The cautions when using the Stepper Motor Controller are described below.
■ Cautions when Changing the PWM Setting
PWM Compare register 1 (PWC1x), PWM Compare register 2 (PWC2x), PWM Selection register 1
(PWS1x), and PWM Selection register 2 (PWS2x) can always be accessed. To change the setting of the
PWM's "H" width or PWM output, write the setting values to these registers, then set the BS bit of PWM
Selection register 2 to "1" (or do this simultaneously).
If the BS bit is set to "1", the new setting value will become effective at the end of the current PWM cycle,
and the BS bit is automatically cleared.
If setting the BS bit to "1" and resetting the BS bit at the end of the PWM cycle both occur at the same time,
writing "1" has priority and resetting the BS bit will be cancelled.
The PWM compare registers 1 and 2 (PWC1x, PWC2x) and the PWM selection registers 1 and 2 (PWS1x,
PWS2x) can be accessed at any time. However, to change setting of the "H" width of PWM or to change the
PWM output, "1" must be written to the BS bit of the PWM2 selection register after (or and at the same time)
a setting is written to those registers (the PWM compare register 1 and 2 and the PWM selection register 1
and 2).
When "1" is set to the BS bit, the new setting is enabled at the end of the current PWM cycle and the BS bit
is cleared automatically.
Also, when "1" is written to the BS bit and the BS bit is reset at the end of the PWM cycle simultaneously,
"1" is written to the BS and resetting of the BS bit is cancelled.
706
MB96300 Super Series Hardware Manual