C8051F321-GM Silicon Laboratories Inc, C8051F321-GM Datasheet - Page 244

• Manufacturer Part Number: C8051F321-GM
• Description: IC 8051 MCU 16K FLASH 28MLP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F32xr

Specifications of C8051F321-GM

• Program Memory Type: FLASH
• Program Memory Size: 16KB (16K x 8)
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 21
• Ram Size: 2.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 13x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: C8051F3x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 2.25 KB
• Interface Type: I2C/SMBus/SPI/UART/USB
• Maximum Clock Frequency: 25 MHz
• Number Of Programmable I/os: 21
• Number Of Timers: 4
• Operating Supply Voltage: 2.7 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: C8051F320DK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 13-ch x 10-bit or 17-ch x 10-bit
• No. Of I/o's: 21
• Ram Memory Size: 1280Byte
• Cpu Speed: 25MHz
• No. Of Timers: 4
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 336-1480 - DAUGHTER CARD TOOLSTCK C8051F321770-1006 - ISP 4PORT FOR SILABS C8051F MCU336-1449 - ADAPTER PROGRAM TOOLSTICK F321336-1260 - DEV KIT FOR C8051F320/F321
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1261

C8051F320/1
20.2.6. 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 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. The duty
cycle for 16-Bit PWM Mode is given by Equation 20.3.
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 20.3, 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’.
244
PCA0CPLn
Write to
Reset
PCA0CPHn
Write to
0
ENB
ENB
1
W
M
P
1
6
n
1
O
M
E
C
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
W
M
P
n
E
C
C
F
n
x
Equation 20.3. 16-Bit PWM Duty Cycle
Figure 20.9. PCA 16-Bit PWM Mode
DutyCycle
Enable
PCA0CPHn
PCA0H
=
16-bit Comparator
Rev. 1.1
(
---------------------------------------------------- -
65536 PCA0CPn
PCA0CPLn
PCA0L
–
65536
Overflow
match
S
R
)
SET
CLR
Q
Q
CEXn
Crossbar
Port I/O