sc9s12hy64j0vllr Freescale Semiconductor, Inc, sc9s12hy64j0vllr Datasheet - Page 709

• Manufacturer Part Number: sc9s12hy64j0vllr
• Description: S12 Microcontrollers Mcu 16-bit Hcs12 Cisc 32kb Flash 5v Tray
• Manufacturer: Freescale Semiconductor, Inc

19.4.2
The PWM duty cycle for the motor controller channel x can be determined by dividing the decimal
representation of bits D[10:0] in MCDCx by the decimal representation of the bits P[10:0] in MCPER and
multiplying the result by 100% as shown in the equation below:
Whenever D[10:0] >= P[10:0], a constant low level (RECIRC = 0) or high level (RECIRC = 1) will be
output.
19.4.3
Figure 19-22
The peripheral bus clock is the source for the motor controller counter prescaler. The motor controller
counter clock rate, f
the MCPRE[1:0] bits in motor controller control register 0 (MCCTL0). The motor controller channel
frequency of operation can be calculated using the following formula if DITH = 0:
Freescale Semiconductor
MPPRE0, MPPRE1
PWM Duty Cycle
Motor Controller Counter Clock Source
shows how the PWM motor controller timer counter clock source is selected.
Prescaler Select
Motor Controller
x = PWM Channel Number = 0, 1, 2, 3 ... 8. This equation is only valid if
DUTY <= MCPER and MCPER is not equal to 0.
Counter Clock
TC
Effective PWM Channel X % Duty Cycle
, is set by selecting the appropriate prescaler value. The prescaler is selected with
Motor Channel Frequency (Hz)
Timer
Figure 19-22. Motor Controller Counter Clock Selection
Clock f
Peripheral
MC9S12HY/HA-Family Reference Manual, Rev. 1.04
Motor Controller Timer
Bus
Counter Prescaler
BUS
CLK
1/2
1/4
1/8
1
Generator
Clock
Motor Controller Timer
Counter Clock f
NOTE
=
TC
------------------------------ -
MCPER M
f
Clocks and
Reset
Generator
Module
=
TC
--------------------- 100%
MCPER
DUTY
11-Bit Motor Controller
Timer Counter
Motor Controller (MC10B8CV1)
709