CM6533-N Datasheet, PDF (48/60 Pages) C-Media Electronics – USB 2.0 Full-Speed compliant

CM6533,CM6533N,CM6533X1,CM6533DH
USB Audio Chip
6.12 Tri-Colored LED Control Setting
PWM function is generated by LED counter and output the PWM signal to GPIO pin. The 8-bit counter counts modulus
256 controlled by LED freq, LED duty register. The LED unit register controls PWM resolution. When the LED freq
register value is equal to the LED duty register (high), the PWM output also goes high. When the LED freq, LED duty
register reaches zero, the PWM output is forced to go low. The low-to-high ratio (duty) of the PWM output is LED
duty/LED freq.
LED duty
00H
01H
80H
FEH
LED freq
FFH
FFH
FFH
FFH
LED unit
(256 step)
00:10.5ms
01:5.45ms
10:2.73ms
11:1.36ms
PWM duty range
00H/FFH
~FEH/FFH
The Output Duty of PWM has different timings. Duty range is from 0/256~255/256.
LED duty/LED freq
=00H/FFH
LED duty/LED freq
=01H/FFH
LED duty/LED freq
=80H/FFH
LED duty/LED freq
=FEH/FFH
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Rev.1.6
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