C8051F312 Silicon Laboratories Inc, C8051F312 Datasheet - Page 207

• Manufacturer Part Number: C8051F312
• Description: IC 8051 MCU 8K FLASH 32LQFP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F31xr

Specifications of C8051F312

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: POR, PWM, Temp Sensor, WDT
• Number Of I /o: 29
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 21x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Other names: 336-1151

18.2.2. Software Timer (Compare) Mode
In Software Timer mode, the PCA counter/timer value is compared to the module's 16-bit capture/compare
register (PCA0CPHn and PCA0CPLn). When a match occurs, the Capture/Compare Flag (CCFn) in
PCA0CN is set to logic 1 and an interrupt request is generated if CCF interrupts are enabled. The CCFn bit
is not automatically cleared by hardware when the CPU vectors to the interrupt service routine, and must
be cleared by software. Setting the ECOMn and MATn bits in the PCA0CPMn register enables Software
Timer mode.
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’.
PCA0CPLn
Write to
Reset
PCA0CPHn
Write to
0
1
ENB
ENB
Figure 18.5. PCA Software Timer Mode Diagram
W
M
P
1
6
n
x
C
O
M
E
n
PCA0CPMn
C
A
P
P
n
0 0
C
A
P
N
n
M
A
T
n
O
G
T
n
0 0
W
P
M
n
E
C
C
F
n
x
Enable
PCA
Timebase
Rev. 1.7
PCA0CPLn
PCA0L
16-bit Comparator
C8051F310/1/2/3/4/5/6/7
PCA0CPHn
PCA0H
Match
C
F
C
R
PCA0CN
0
1
C
C
F
4
C
C
F
3
C
C
F
2
C
C
F
1
PCA Interrupt
C
C
F
0
207