BIG 8051 Manual
6
C8051F040 microcontroller
The BIG8051 system has a 100-pin microcontroller C8051F040 in
TQFP package. Today over fifty companies produce variations of the
8051. Several of these companies have over fifty variations of this sys-
tem. To bring things into context, over 100 million 8051’s are sold
each year. Our microcontroller appears to be soldered on the MCU
card.
Originally, 8051 belongs to the MCS-51 family of microcontrollers.
MCS-51 was developed by Intel but other manufacturers are second
sources of this family. The MCS-51, now commonly referred to as the
8051 is a Harvard architecture, consisting of physically separate storage
and signal pathways for instructions and data. Today, most processors
implement such separate signal pathways for performance reasons. The
original MCS-51 featured 8-bit ALU, registers, and data busses. The
following table shows the features of the MCS-51 and the BIG8051:
Microcontroller 8051F040
Pinout [3]
MCS-51
BIG8051
4K bytes internal ROM
128 bytes internal RAM
Four 8-bit I/O ports
Two 16-bit timers
Serial interface
64K external code memory
space
64K external data memory
space
210 bit-addressable locations
Pipelined instruction architecture
executes 70% of instruction set in
1 or 2 system clocks
Up to 25 MIPS throughout with
25MHz clock
4352 bytes internal RAM
64kB Flash; in-system program-
mable 512-byte sectors
BOSCH Controller Area Network
(CAN 2.0B), hardware SMBus™
(I2C™ Compatible), SPI™, and
two UART serial ports available
concurrently
Internal calibrated programmable
oscillator: 3 to 24.5 MHz; etc.
The microcontroller can be replaced with another one if desired, but it is
important to make sure that they are compatible with the pinouts. “1-wire
serial communication enables data to be transferred over one single com-
munication line, while the process itself is under control of the
master
microcontroller. The advantage of this communication is that only one
microcontroller pin is used. All
slave
devices have unique ID code, which
enables the
master
device to easily identify all devices sharing the same
communication bus
