C8051F131R Silicon Labs, C8051F131R Datasheet - Page 318

• Manufacturer Part Number: C8051F131R
• Description: 8-bit Microcontrollers - MCU 128kB 100MIPS 8448B RAM
• Manufacturer: Silicon Labs

Specifications of C8051F131R

• Product Category: 8-bit Microcontrollers - MCU
• Core: 8051
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 100 MHz
• Program Memory Size: 128 KB
• Data Ram Size: 8.25 KB
• On-chip Adc: Yes
• Operating Supply Voltage: 2.7 V to 3.6 V
• Package / Case: TQFP-64
• Mounting Style: SMD/SMT
• A/d Bit Size: 10 bit
• A/d Channels Available: 9
• Data Rom Size: 64 KB
• Interface Type: I2C, SMBus, SPI, UART
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Number Of Programmable I/os: 32
• Number Of Timers: 16 bit
• Processor Series: C8051
• Program Memory Type: Flash
• Factory Pack Quantity: 500
• Supply Voltage - Max: 3.6 V
• Supply Voltage - Min: 3 V

C8051F120/1/2/3/4/5/6/7
C8051F130/1/2/3
23.2.2. Capture Mode
In Capture Mode, Timer 2, 3, and 4 will operate as a 16-bit counter/timer with capture facility. When the
Timer External Enable bit (found in the TMRnCN register) is set to ‘1’, a high-to-low transition on the TnEX
input pin (Timer 3 shares the T2EX pin with Timer 2) causes the 16-bit value in the associated timer (THn,
TLn) to be loaded into the capture registers (RCAPnH, RCAPnL). If a capture is triggered in the counter/
timer, the Timer External Flag (TMRnCN.6) will be set to ‘1’ and an interrupt will occur if the interrupt is
enabled. See
figuration of interrupt sources.
As the 16-bit timer register increments and overflows TMRnH:TMRnL, the TFn Timer Overflow/Underflow
Flag (TMRnCN.7) is set to ‘1’ and an interrupt will occur if the interrupt is enabled. The timer can be config-
ured to count down by setting the Decrement Enable Bit (TMRnCF.0) to ‘1’. This will cause the timer to
decrement with every timer clock/count event and underflow when the timer transitions from 0x0000 to
0xFFFF. Just as in overflows, the Overflow/Underflow Flag (TFn) will be set to ‘1’, and an interrupt will
occur if enabled.
Counter/Timer with Capture mode is selected by setting the Capture/Reload Select bit CP/RLn
(TMRnCN.0) and the Timer 2, 3, and 4 Run Control bit TRn (TMRnCN.2) to logic 1. The Timer 2, 3, and 4
respective External Enable EXENn (TMRnCN.3) must also be set to logic 1 to enable captures. If EXENn
is cleared, transitions on TnEX will be ignored.
318
External Clock
SYSCLK
(XTAL1)
Tn
TnE
X
Section “11.3. Interrupt Handler” on page 154
Crossbar
8
Figure 23.4. T2, 3, and 4 Capture Mode Block Diagram
2
12
Crossbar
EXENn
TRn
0
1
TMRnCF
M
T
n
1
M
T
n
0
O
G
T
n
Rev. 1.4
O
T
n
E
TCLK
D
C
E
n
RCAPnL
TMRnL
0xFF
for further information concerning the con-
RCAPnH
TMRnH
0xFF
Toggle Logic
CP/RLn
EXENn
EXFn
C/Tn
TRn
TFn
0
1
Interrupt
(Port Pin)
Tn