S9S12P64J0CFT Freescale Semiconductor, S9S12P64J0CFT Datasheet - Page 358

• Manufacturer Part Number: S9S12P64J0CFT
• Description: 16-bit Microcontrollers - MCU 16-bit 64K Flash
• Manufacturer: Freescale Semiconductor

Specifications of S9S12P64J0CFT

• Rohs: yes
• Core: S12
• Processor Series: MC9S12P
• Data Bus Width: 16 bit
• Maximum Clock Frequency: 25 MHz
• Program Memory Size: 64 KB
• Data Ram Size: 4 KB
• On-chip Adc: Yes
• Operating Supply Voltage: 3.15 V to 5.5 V
• Operating Temperature Range: - 40 C to + 125 C
• Package / Case: QFN-48
• Mounting Style: SMD/SMT

Pulse-Width Modulator (PWM8B6CV1) Block Description
PWM counter matches the duty register the output flip-flop changes state causing the PWM waveform to
also change state. A match between the PWM counter and the period register resets the counter and the
output flip-flop as shown in
duty register to the associated registers as described in
counter counts from 0 to the value in the period register – 1.
To calculate the output frequency in left aligned output mode for a particular channel, take the selected
clock source frequency for the channel (A, B, SA, or SB) and divide it by the value in the period register
for that channel.
As an example of a left aligned output, consider the following case:
Shown below is the output waveform generated.
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PWMx frequency = clock (A, B, SA, or SB) / PWMPERx
PWMx duty cycle (high time as a% of period):
— Polarity = 0 (PPOLx = 0)
— Polarity = 1 (PPOLx = 1)
Clock source = bus clock, where bus clock = 10 MHz (100 ns period)
PPOLx = 0
PWMPERx = 4
PWMDTYx = 1
PWMx frequency = 10 MHz/4 = 2.5 MHz
PWMx period = 400 ns
PWMx duty cycle = 3/4 *100% = 75%
Duty cycle = [(PWMPERx-PWMDTYx)/PWMPERx] * 100%
Duty cycle = [PWMDTYx / PWMPERx] * 100%
Changing the PWM output mode from left aligned output to center aligned
output (or vice versa) while channels are operating can cause irregularities
in the PWM output. It is recommended to program the output mode before
enabling the PWM channel.
PPOLx = 0
PPOLx = 1
Figure 10-36. PWM Left Aligned Output Waveform
Figure 10-35
S12P-Family Reference Manual, Rev. 1.13
PWMDTYx
as well as performing a load from the double buffer period and
NOTE
Period = PWMPERx
Section 10.4.2.3, “PWM Period and Duty.”
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