C8051T610DK Silicon Laboratories Inc, C8051T610DK Datasheet - Page 198

• Manufacturer Part Number: C8051T610DK
• Description: KIT DEV FOR C8051T61X MCU'S
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051T610DK

• Contents: Board, daughter boards, power adapter, cables, documentation and software
• Processor To Be Evaluated: C8051T61x
• Interface Type: USB
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: C8051T610
• For Use With: 336-1507 - DAUGHTER BOARD T610 24QFN SOCKET336-1506 - DAUGHTER BOARD T610 28QFN SOCKET336-1505 - DAUGHT BOARD T610 32TQFP SOCKET
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1443

C8051T610/1/2/3/4/5/6/7
26.3.5. 8-bit Pulse Width Modulator Mode
The duty cycle of the PWM output signal in 8-bit PWM mode is varied using the module's PCA0CPLn cap-
ture/compare register. When the value in the low byte of the PCA counter/timer (PCA0L) is equal to the
value in PCA0CPLn, the output on the CEXn pin will be set. When the count value in PCA0L overflows, the
CEXn output will be reset (see Figure 26.8). Also, when the counter/timer low byte (PCA0L) overflows from
0xFF to 0x00, PCA0CPLn is reloaded automatically with the value stored in the module’s capture/compare
high byte (PCA0CPHn) without software intervention. Setting the ECOMn and PWMn bits in the
PCA0CPMn register enables 8-Bit Pulse Width Modulator mode. If the MATn bit is set to 1, the CCFn flag
for the module will be set each time an 8-bit comparator match (rising edge) occurs. The duty cycle for 8-
Bit PWM Mode is given in Equation 26.2.
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 26.2, the largest duty cycle is 100% (PCA0CPHn = 0), and the smallest duty cycle is
0.39% (PCA0CPHn = 0xFF). A 0% duty cycle may be generated by clearing the ECOMn bit to 0.
198
PCA0CPLn
Write to
Reset
PCA0CPHn
Write to
0
ENB
ENB
1
W
M
P
1
6
n
0
Figure 26.8. PCA 8-Bit PWM Mode Diagram
E
C
O
M
n
PCA0CPMn
C
A
P
P
n
0 0 x 0
C
A
P
N
n
Equation 26.2. 8-Bit PWM Duty Cycle
M
A
T
n
O
G
T
n
Duty Cycle
P
W
M
n
C
C
E
F
n
x
PCA Timebase
Enable
=
PCA0CPHn
Comparator
PCA0CPLn

-------------------------------------------------- -
Rev 1.0
PCA0L
256 PCA0CPHn
8-bit
–
256
Overflow
COVF
match
S
R
SET
CLR

Q
Q
CEXn
Crossbar
Port I/O