C8051F337-GM Silicon Laboratories Inc, C8051F337-GM Datasheet - Page 192

• Manufacturer Part Number: C8051F337-GM
• Description: IC MCU 16K FLASH 20QFN
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F33xr

Specifications of C8051F337-GM

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 17
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-QFN
• Processor Series: C8051F3x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 768 B
• Interface Type: I2C, SPI, UART
• Maximum Clock Frequency: 25 MHz
• Number Of Programmable I/os: 17
• 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: KSK-SL-TOOLSTICK, PK51, CA51, A51, ULINK2
• Development Tools By Supplier: C8051F336DK
• Minimum Operating Temperature: - 40 C
• For Use With: 336-1451 - ADAPTER PROGRAM TOOLSTICK F330
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Details
• Other names: 336-1428-5

C8051F336/7/8/9
24.2.3. Low-Frequency Oscillator (LFO) Capture Mode
The Low-Frequency Oscillator Capture Mode allows the LFO clock to be measured against the system
clock or an external oscillator source. Timer 2 can be clocked from the system clock, the system clock
divided by 12, or the external oscillator divided by 8, depending on the T2ML (CKCON.4), and T2XCLK
settings.
Setting TF2CEN to 1 enables the LFO Capture Mode for Timer 2. In this mode, T2SPLIT should be set to
0, as the full 16-bit timer is used. Upon a falling edge of the low-frequency oscillator, the contents of Timer
2 (TMR2H:TMR2L) are loaded into the Timer 2 reload registers (TMR2RLH:TMR2RLL) and the TF2H flag
is set. By recording the difference between two successive timer capture values, the LFO clock frequency
can be determined with respect to the Timer 2 clock. The Timer 2 clock should be much faster than the
LFO to achieve an accurate reading.
192
External Clock / 8
Figure 24.6. Timer 2 Low-Frequency Oscillation Capture Mode Block Diagram
SYSCLK / 12
Low-Frequency
SYSCLK
Oscillator
T2XCLK
0
1
M
H
T
3
M
T
3
L
CKCON
M
H
T
2
T
M
0
1
2
L
M
T
1
M
T
0
C
S
A
1
TF2CEN
S
C
A
0
TR2
Rev.1.0
Capture
TCLK
TMR2RLL TMR2RLH
TMR2L
TMR2H
TF2CEN
T2SPLIT
TF2LEN
T2XCLK
TF2H
TF2L
TR2
Interrupt