C8051F352 Datasheet, PDF (21/234 Pages) Silicon Laboratories – 8 k ISP Flash MCU Family

C8051F350/1/2/3
1.1. CIP-51™ Microcontroller
1.1.1. Fully 8051 Compatible Instruction Set
The C8051F35x devices use Silicon Labs’ proprietary CIP-51 microcontroller core. The CIP-51 is fully
compatible with the MCS-51™ instruction set. Standard 803x/805x assemblers and compilers can be used
to develop software. The C8051F35x family has a superset of all the peripherals included with a standard
8052.
1.1.2. Improved Throughput
The CIP-51 employs a pipelined architecture that greatly increases its instruction throughput over the stan-
dard 8051 architecture. In a standard 8051, all instructions except for MUL and DIV take 12 or 24 system
clock cycles to execute, and usually have a maximum system clock of 12 to 24 MHz. By contrast, the CIP-
51 core executes 70% of its instructions in one or two system clock cycles, with no instructions taking more
than eight system clock cycles.
With the CIP-51's system clock running at 50 MHz, it has a peak throughput of 50 MIPS. The CIP-51 has a
total of 109 instructions. The table below shows the total number of instructions that require each execution
time.
Clocks to Execute
1
2
2/3
3
3/4
4
4/5
5
8
Number of Instructions
26
50
5
14
7
3
1
2
1
1.1.3. Additional Features
The C8051F350/1/2/3 SoC family includes several key enhancements to the CIP-51 core and peripherals
to improve performance and ease of use in end applications.
An extended interrupt handler allows the numerous analog and digital peripherals to operate indepen-
dently of the controller core and interrupt the controller only when necessary. By requiring less intervention
from the microcontroller core, an interrupt-driven system is more efficient and allows for easier implemen-
tation of multi-tasking, real-time systems.
Eight reset sources are available: power-on reset circuitry (POR), an on-chip V_DD monitor, a Watchdog
Timer, a Missing Clock Detector, a voltage level detection from Comparator0, a forced software reset, an
external reset pin, and an illegal Flash access 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. A clock multiplier allows for operation at up to 50 MHz. An external oscillator can also be
extremely useful in low power applications, allowing the MCU to run from a slow (power saving) source,
while periodically switching to the fast internal oscillator as needed.
Rev. 1.1
21