MEC1404 Datasheet, PDF (390/572 Pages) Microchip Technology – Keyboard and Embedded Controller Products for Notebook PC

MEC140X/1X
TABLE 28-7: SYMMETRIC BREATHING MODE REGISTER USAGE
Rising/ Falling
Ramp Times
in Figure 28-3,
"Clipping Example"
Duty Cycle
Segment
Index
Symmetric Mode Register Fields Utilized
X
000xxxxxb
000b
STEP[0]/INT[0]
X
001xxxxxb
001b
STEP[1]/INT[1]
X
010xxxxxb
010b
STEP[2]/INT[2]
X
011xxxxxb
011b
STEP[3]/INT[3]
X
100xxxxxb
100b
STEP[4]/INT[4]
X
101xxxxxb
101b
STEP[5]/INT[5]
X
110xxxxxb
110b
STEP[6]/INT[6]
X
111xxxxxb
111b
STEP[7]/INT[7]
Note: In Symmetric Mode the Segment_Index[2:0] = Duty Cycle Bits[7:5]
Bits[3:0]
Bits[7:4]
Bits[11:8]
Bits[15:12]
Bits[19:16]
Bits[23:20]
Bits[27:24]
Bits[31:28]
TABLE 28-8: ASYMMETRIC BREATHING MODE REGISTER USAGE
Rising/ Falling
Ramp Times
in Figure 28-3,
"Clipping Example"
Duty Cycle
Segment
Index
Asymmetric Mode Register Fields Utilized
Rising
Rising
Rising
Rising
falling
falling
falling
00xxxxxxb
01xxxxxxb
10xxxxxxb
11xxxxxxb
00xxxxxxb
01xxxxxxb
10xxxxxxb
000b
001b
010b
011b
100b
101b
110b
STEP[0]/INT[0]
STEP[1]/INT[1]
STEP[2]/INT[2]
STEP[3]/INT[3]
STEP[4]/INT[4]
STEP[5]/INT[5]
STEP[6]/INT[6]
Bits[3:0]
Bits[7:4]
Bits[11:8]
Bits[15:12]
Bits[19:16]
Bits[23:20]
Bits[27:24]
falling
11xxxxxxb
111b
STEP[7]/INT[7]
Bits[31:28]
Note: In Asymmetric Mode the Segment_Index[2:0] is the bit concatenation of following: Segment_Index[2] =
(FALLING RAMP TIME in Figure 28-3, "Clipping Example") and Segment_Index[1:0] = Duty Cycle Bits[7:6].
28.9.2 BLINKING CONFIGURATION
The Delay counter and the PWM counter are the same as in the breathing configuration, except in this configuration
they are connected differently. The Delay counter is clocked on either the 32.768 KHz clock or the 48 MHz clock, rather
than the output of the PWM. The PWM counter is clocked by the zero output of the Delay counter, which functions as a
prescalar for the input clocks to the PWM. The Delay counter is reloaded from the LD field of the LED_DELAY register.
When the LD field is 0 the input clock is passed directly to the PWM counter without prescaling. In Blinking/PWM mode
the PWM counter is always 8-bit, and the PSIZE parameter has no effect.
DS00001956D-page 390
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