S9S12P64J0CFTR Freescale Semiconductor, S9S12P64J0CFTR Datasheet - Page 349

• Manufacturer Part Number: S9S12P64J0CFTR
• Description: 16-bit Microcontrollers - MCU 16-bit 64K Flash
• Manufacturer: Freescale Semiconductor

Specifications of S9S12P64J0CFTR

• 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

Read: anytime
Write: anytime
10.3.2.14 PWM Channel Duty Registers (PWMDTYx)
There is a dedicated duty register for each channel. The value in this register determines the duty of the
associated PWM channel. The duty value is compared to the counter and if it is equal to the counter value
a match occurs and the output changes state.
The duty registers for each channel are double buffered so that if they change while the channel is enabled,
the change will NOT take effect until one of the following occurs:
In this way, the output of the PWM will always be either the old duty waveform or the new duty waveform,
not some variation in between. If the channel is not enabled, then writes to the duty register will go directly
to the latches as well as the buffer.
Reference
To calculate the output duty cycle (high time as a % of period) for a particular channel:
Freescale Semiconductor
Module Base + 0x0017
Reset
•
•
•
•
•
W
R
The effective period ends
The counter is written (counter resets to 0x0000)
The channel is disabled
Polarity = 0 (PPOLx = 0)
Polarity = 1 (PPOLx = 1)
Duty cycle = [(PWMPERx PWMDTYx)/PWMPERx] * 100%
Duty cycle = [PWMDTYx / PWMPERx] * 100%
Section 10.4.2.3, “PWM Period and Duty,”
Bit 7
0
7
Reads of this register return the most recent value written. Reads do not
necessarily return the value of the currently active duty due to the double
buffering scheme.
Depending on the polarity bit, the duty registers will contain the count of
either the high time or the low time. If the polarity bit is 1, the output starts
high and then goes low when the duty count is reached, so the duty registers
contain a count of the high time. If the polarity bit is 0, the output starts low
and then goes high when the duty count is reached, so the duty registers
contain a count of the low time.
Figure 10-26. PWM Channel Period Registers (PWMPER5)
6
0
6
S12P-Family Reference Manual, Rev. 1.13
5
0
5
NOTE
NOTE
4
0
4
for more information.
Pulse-Width Modulator (PWM8B6CV1) Block Description
3
0
3
2
0
2
1
0
1
Bit 0
0
0
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