C8051F310/1/2/3/4/5/6/7
1.1.
CIP-51™ Microcontroller Core
1.1.1. Fully 8051 Compatible
The C8051F31x family utilizes Silicon Laboratories' 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 CIP-51 core offers all the peripherals included with a standard 8052, includ-
ing four 16-bit counter/timers, a full-duplex UART with extended baud rate configuration, an enhanced SPI
port, 1280 bytes of internal RAM, 128 byte Special Function Register (SFR) address space, and 29/25/21
I/O pins.
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 with a maximum system clock of 12-to-24 MHz. By contrast, the CIP-51 core exe-
cutes 70% of its instructions in one or two system clock cycles, with only four instructions taking more than
four system clock cycles.
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
Number of Instructions
1
26
2
50
2/3
5
3
14
3/4
7
4
3
4/5
1
5
2
8
1
With the CIP-51's maximum system clock at 25 MHz, it has a peak throughput of 25 MIPS. Figure 1.9
shows a comparison of peak throughputs for various 8-bit microcontroller cores with their maximum sys-
tem clocks.
25
20
MIPS
15
10
5
Silicon Labs
Microchip
Philips
ADuC812
CIP-51
PIC17C75x
80C51
8051
(25 MHz clk)
(33 MHz clk)
(33 MHz clk)
(16 MHz clk)
Figure 1.9. Comparison of Peak MCU Execution Speeds
Rev. 1.7
27
SILABS [ SILICON LABORATORIES ]
