ST72321AR6-Auto STMicroelectronics, ST72321AR6-Auto Datasheet - Page 89

• Manufacturer Part Number: ST72321AR6-Auto
• Description: 8-bit MCU for automotive with 32 Kbyte Flash, 10-bit ADC, timers, SPI, SCI and I2C interfaces
• Manufacturer: STMicroelectronics

Specifications of ST72321AR6-Auto

• Hdflash Endurance: 100 cycles, data retention 20 years
• Clock Sources: crystal/ceramic resonator oscillators, internal RC oscillator and bypass for external clock
• 4 Power Saving Modes: Halt, Active Halt, Wait and Slow

ST72321xx-Auto
12.2.5
Note:
Figure 36. Output compare control
Independent PWM signal generation
This mode allows up to four Pulse Width Modulated signals to be generated on the PWMx
output pins with minimum core processing overhead. This function is stopped during Halt
mode.
Each PWMx output signal can be selected independently using the corresponding OEx bit
in the PWM Control register (PWMCR). When this bit is set, the corresponding I/O pin is
configured as output push-pull alternate function.
The PWM signals all have the same frequency which is controlled by the counter period and
the ARTARR register value.
When a counter overflow occurs, the PWMx pin level is changed depending on the
corresponding OPx (output polarity) bit in the PWMCR register. When the counter reaches
the value contained in one of the output compare register (OCRx) the corresponding PWMx
pin level is restored.
It should be noted that the reload values will also affect the value and the resolution of the
duty cycle of the PWM output signal. To obtain a signal on a PWMx pin, the contents of the
OCRx register must be greater than the contents of the ARTARR register.
The maximum available resolution for the PWMx duty cycle is:
To get the maximum resolution (1/256), the ARTARR register must be 0. With this maximum
resolution, 0% and 100% can be obtained by changing the polarity.
f
COUNTER
OCRx
PWMDCRx
PWMx
COUNTER
FDh
FEh
ARTARR = FDh
FDh
f
PWM
Resolution = 1 / (256 - ARTARR)
Doc ID 13829 Rev 1
FFh
= f
FDh
COUNTER
FDh
/ (256 - ARTARR)
FEh
FFh
PWM auto-reload timer (ART)
FEh
FDh
FEh
FEh
FFh
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