C8051F360DK Silicon Laboratories Inc, C8051F360DK Datasheet - Page 272

• Manufacturer Part Number: C8051F360DK
• Description: KIT DEV FOR C8051F360 FAMILY
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F360DK

• Contents: Evaluation Board, Power Supply, USB Cables, Adapter and Documentation
• Processor To Be Evaluated: C8051F36x
• Interface Type: USB
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: C8051F360, F361, F362, F363, F364, F365, F366, F367, F368, F369
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1410

C8051F360/1/2/3/4/5/6/7/8/9
22.2.6. 16-Bit Pulse Width Modulator Mode
Each PCA0 module may also be operated in 16-Bit PWM mode. In this mode, the 16-bit capture/compare
module defines the number of PCA0 clocks for the low time of the PWM signal. When the PCA0 counter
matches the module contents, the output on CEXn is asserted high; when the counter overflows, CEXn is
asserted low. To output a varying duty cycle, new value writes should be synchronized with PCA0 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, CCFn should also be set to logic ‘1’ to enable match inter-
rupts. The duty cycle for 16-Bit PWM Mode is given by Equation 22.3.
Important Note About Capture/Compare Registers: When writing a 16-bit value to the PCA0 Capture/
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 22.3, 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’.
22.3. Watchdog Timer Mode
A programmable watchdog timer (WDT) function is available through the PCA Module 5. The WDT is used
to generate a reset if the time between writes to the WDT update register (PCA0CPH5) exceed a specified
limit. The WDT can be configured and enabled/disabled as needed by software.
With the WDTE bit set in the PCA0MD register, Module 5 operates as a watchdog timer (WDT). The
Module 5 high byte is compared to the PCA counter high byte; the Module 5 low byte holds the offset to be
used when WDT updates are performed. The Watchdog Timer is enabled on reset. Writes to some
PCA registers are restricted while the Watchdog Timer is enabled.
272
W
M
P
1
6
n
1
PCA0CPMn
O
M
E
C
n
C
A
P
P
n
0 0 0 0
C
A
P
N
n
M
A
T
n
PCA Timebase
O
G
T
n
W
P
M
n
E
C
C
F
n
0
Enable
Equation 22.3. 16-Bit PWM Duty Cycle
PCA0CPHn
Figure 22.9. PCA 16-Bit PWM Mode
PCA0H
DutyCycle
16-bit Comparator
PCA0CPLn
PCA0L
=
Rev. 1.0
(
---------------------------------------------------- -
65536 PCA0CPn
Overflow
–
65536
match
S
R
SET
CLR
Q
Q
)
CEXn
Crossbar
Port I/O