C8051T600QDB Silicon Laboratories Inc, C8051T600QDB Datasheet - Page 169

• Manufacturer Part Number: C8051T600QDB
• Description: BOARD SOCKET DAUGHTER QFN
• Manufacturer: Silicon Laboratories Inc

Specifications of C8051T600QDB

• Module/board Type: Socket Module - QFN
• Data Bus Width: 8 bit
• Operating Supply Voltage: + 1.8 V to + 3.6 V
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: C8051T600DK
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1406

26.3.6. 16-Bit Pulse Width Modulator Mode
A PCA module may also be operated in 16-Bit PWM mode. In this mode, the 16-bit Capture/Compare
module defines the number of PCA clocks for the low time of the PWM signal. When the PCA counter
matches the module contents, the output on CEXn is asserted high; when the 16-bit counter overflows,
CEXn is asserted low. To output a varying duty cycle, new value writes should be synchronized with PCA
CCFn match interrupts. 16-Bit PWM Mode is enabled by setting the ECOMn, PWMn, and PWM16n bits in
the PCA0CPMn register. For a varying duty cycle, match interrupts should be enabled (ECCFn = 1 AND
MATn = 1) to help synchronize the Capture/Compare register writes. If the MATn bit is set to 1, the CCFn
flag for the module will be set each time a 16-bit comparator match (rising edge) occurs. The CF flag in
PCA0CN can be used to detect the overflow (falling edge). The duty cycle for 16-Bit PWM Mode is given
by Equation 26.3.
Important Note about Capture/Compare Registers: When writing a 16-bit value to the PCA0 Cap-
ture/Compare registers, the low byte should always be written first. Writing to PCA0CPLn clears the
ECOMn bit to 0; writing to PCA0CPHn sets ECOMn to 1.
Using Equation 26.3, the largest duty cycle is 100% (PCA0CPn = 0), and the smallest duty cycle is
0.0015% (PCA0CPn = 0xFFFF). A 0% duty cycle may be generated by clearing the ECOMn bit to 0.
PCA0CPLn
Write to
Reset
PCA0CPHn
Write to
0
ENB
ENB
1
P
W
M
1
6
n
1
E
C
O
M
n
PCA0CPMn
C
A
P
P
n
0 0 x 0
C
A
P
N
n
M
A
T
n
PCA Timebase
O
G
T
n
Equation 26.3. 16-Bit PWM Duty Cycle
P
W
M
n
E
C
C
F
n
x
Figure 26.9. PCA 16-Bit PWM Mode
Duty Cycle
Enable
PCA0CPHn
PCA0H
=
16-bit Comparator
Rev. 1.2

---------------------------------------------------- -
65536 PCA0CPn
PCA0CPLn
PCA0L
–
65536
C8051T600/1/2/3/4/5/6
Overflow
match

S
R
SET
CLR
Q
Q
CEXn
Crossbar
Port I/O
169