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Samsung S3C2440A User Manual

Page 291

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S3C2440A RISC MICROPROCESSOR

PWM TIMER

10-7

PULSE WIDTH MODULATION (PWM)

Write

TCMPBn = 60

Write

TCMPBn = 50

Write

TCMPBn = 40

Write

TCMPBn = 30

Write

TCMPBn = 30

Write

TCMPBn = Next PWM Value

60

50

40

30

30

Figure 10-5. Example of PWM

PWM function can be implemented by using the TCMPBn. PWM frequency is determined by TCNTBn. Figure 10-5
shows a PWM value determined by TCMPBn.

For a higher PWM value, decrease the TCMPBn value. For a lower PWM value, increase the TCMPBn value. If an
output inverter is enabled, the increment/decrement may be reversed.

The double buffering function allows the TCMPBn, for the next PWM cycle, written at any point in the current PWM
cycle by ISR or other routine.