MEC1322 datasheet(334/456 Pages) MICROCHIP

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MEC1322

DS00001719D-page 334

 2014 - 2015 Microchip Technology Inc.

The other registers in the block do not affect the PWM or the LED output in Blinking/PWM mode.

28.9.3

BREATHING EXAMPLES

28.9.3.1

Linear LED brightness change

In this example, the brightness of the LED increases and diminishes in a linear fashion. The entire cycle takes 5 sec-

onds. The rise time and fall time are 1.6 seconds, with a hold time at maximum brightness of 200ms and a hold time at

minimum brightness of 1.6 seconds. The LED brightness varies between full off and full on. The PWM size is set to 8-

bit, so the time unit for adjusting the PWM is approximately 8ms. The registers are configured as follows:

Note:

At a duty cycle value of 00h (in the MIN register), the LED output is fully off. At a duty cycle value of 255h,

the LED output is fully on. Alternatively, In order to force the LED to be fully on, firmware can set the CON-

TROL field of the Configuration register to 3 (always on).

TABLE 28-13: LINEAR EXAMPLE CONFIGURATION

Field

Value

PSIZE

8-bit

MAX

255

MIN

25 ticks (200ms)

200 ticks (1.6s)

Duty cycle most

significant bits

000b

001b

010b

011b

100b

101b

110b

1110

LED_INT

888

8888

LED_STEP

MEC1322 Datasheet(PDF) 334 Page - Microchip Technology