MC9S08AW32CFGE Freescale, MC9S08AW32CFGE Datasheet - Page 177

• Manufacturer Part Number: MC9S08AW32CFGE
• Manufacturer: Freescale

Specifications of MC9S08AW32CFGE

• Cpu Family: HCS08
• Device Core Size: 8b
• Frequency (max): 40MHz
• Interface Type: I2C/SCI/SPI
• Total Internal Ram Size: 2KB
• # I/os (max): 34
• Number Of Timers - General Purpose: 8
• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 2.7V
• On-chip Adc: 8-chx10-bit
• Instruction Set Architecture: CISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 44
• Package Type: LQFP
• Program Memory Type: Flash
• Program Memory Size: 32KB
• Lead Free Status / RoHS Status: Compliant

10.5.2.2
With the output compare function, the TPM can generate timed pulses with programmable position,
polarity, duration, and frequency. When the counter reaches the value in the channel value registers of an
output compare channel, the TPM can set, clear, or toggle the channel pin.
In output compare mode, values are transferred to the corresponding timer channel value registers only
after both 8-bit bytes of a 16-bit register have been written. This coherency sequence can be manually reset
by writing to the channel status/control register (TPMxCnSC).
An output compare event sets a flag bit (CHnF) that can optionally generate a CPU interrupt request.
10.5.2.3
This type of PWM output uses the normal up-counting mode of the timer counter (CPWMS = 0) and can
be used when other channels in the same TPM are configured for input capture or output compare
functions. The period of this PWM signal is determined by the setting in the modulus register
(TPMxMODH:TPMxMODL). The duty cycle is determined by the setting in the timer channel value
register (TPMxCnVH:TPMxCnVL). The polarity of this PWM signal is determined by the setting in the
ELSnA control bit. Duty cycle cases of 0 percent and 100 percent are possible.
As
(duty cycle) of the PWM signal. The time between the modulus overflow and the output compare is the
pulse width. If ELSnA = 0, the counter overflow forces the PWM signal high and the output compare
forces the PWM signal low. If ELSnA = 1, the counter overflow forces the PWM signal low and the output
compare forces the PWM signal high.
When the channel value register is set to 0x0000, the duty cycle is 0 percent. By setting the timer channel
value register (TPMxCnVH:TPMxCnVL) to a value greater than the modulus setting, 100% duty cycle
can be achieved. This implies that the modulus setting must be less than 0xFFFF to get 100% duty cycle.
Because the HCS08 is a family of 8-bit MCUs, the settings in the timer channel registers are buffered to
ensure coherent 16-bit updates and to avoid unexpected PWM pulse widths. Writes to either register,
TPMxCnVH or TPMxCnVL, write to buffer registers. In edge-PWM mode, values are transferred to the
corresponding timer channel registers only after both 8-bit bytes of a 16-bit register have been written and
the value in the TPMxCNTH:TPMxCNTL counter is 0x0000. (The new duty cycle does not take effect
until the next full period.)
Freescale Semiconductor
Figure 10-11
Output Compare Mode
Edge-Aligned PWM Mode
TPMxC
shows, the output compare value in the TPM channel registers determines the pulse width
OVERFLOW
Figure 10-11. PWM Period and Pulse Width (ELSnA = 0)
PULSE
WIDTH
PERIOD
COMPARE
OUTPUT
MC9S08AW60 Data Sheet, Rev 2
OVERFLOW
COMPARE
OUTPUT
Chapter 10 Timer/Pulse-Width Modulator (S08TPMV2)
OVERFLOW
COMPARE
OUTPUT
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