C8051T601-GMR Silicon Laboratories Inc, C8051T601-GMR Datasheet - Page 169

• Manufacturer Part Number: C8051T601-GMR
• Description: MCU 8-Bit C8051T60x 8051 CISC 8KB EPROM 1.8V/3V 14-Pin QFN EP T/R
• Manufacturer: Silicon Laboratories Inc

Specifications of C8051T601-GMR

• Package: 14QFN EP
• Device Core: 8051
• Family Name: C8051T60x
• Maximum Speed: 25 MHz
• Ram Size: 256 Byte
• Program Memory Size: 8 KB
• Operating Supply Voltage: 1.8|3 V
• Data Bus Width: 8 Bit
• Program Memory Type: EPROM
• Number Of Programmable I/os: 8
• Interface Type: I2C/SMBus/UART
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 3

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