C8051F312 Silicon Laboratories Inc, C8051F312 Datasheet - Page 28

• 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

C8051F310/1/2/3/4/5/6/7
1.1.3. Additional Features
The C8051F31x SoC family includes several key enhancements to the CIP-51 core and peripherals to
improve performance and ease of use in end applications.
The extended interrupt handler provides 14 interrupt sources into the CIP-51 (as opposed to 7 for the stan-
dard 8051), allowing numerous analog and digital peripherals to interrupt the controller. An interrupt driven
system requires less intervention by the MCU, giving it more effective throughput. The extra interrupt
sources are very useful when building multi-tasking, real-time systems.
Eight reset sources are available: power-on reset circuitry (POR), an on-chip V
when power supply voltage drops below V
Missing Clock Detector, a voltage level detection from Comparator0, a forced software reset, an external
reset pin, and an errant Flash read/write protection circuit. Each reset source except for the POR, Reset
Input Pin, or Flash error may be disabled by the user in software. The WDT may be permanently enabled
in software after a power-on reset during MCU initialization.
The internal oscillator is factory calibrated to 24.5 MHz ±2%. An external oscillator drive circuit is also
included, allowing an external crystal, ceramic resonator, capacitor, RC, or CMOS clock source to generate
the system clock. If desired, the system clock source may be switched on-the-fly between the internal and
external oscillator circuits. An external oscillator can be extremely useful in low power applications, allow-
ing the MCU to run from a slow (power saving) external crystal source, while periodically switching to the
fast internal oscillator as needed.
28
XTAL1
XTAL2
Oscillator
Oscillator
External
Internal
Drive
Px.x
Px.x
Figure 1.10. On-Chip Clock and Reset
Clock Select
System
Clock
Comparator 0
+
-
Detector
Missing
C0RSEF
Clock
(one-
shot)
Microcontroller
EN
Extended Interrupt
CIP-51
RST
Handler
Core
WDT
PCA
as given in Table 9.1 on page 110), a Watchdog Timer, a
EN
VDD
Rev. 1.7
System Reset
Supply
Monitor
+
-
Enable
(Software Reset)
SWRSF
'0'
Power On
Reset
Operation
FLASH
Errant
DD
(wired-OR)
monitor (forces reset
Reset
Funnel
/RST