Freescale Semiconductor’s MCF51CN
ColdFire V1 microcontroller tops the
company’s Tower System development
boards (see the figure). The $99 kit delivers
a complete development package
including a copy of the Freescale MQX
real-time operating system.
The tower consists of a pair of “elevator”
boards with four inexpensive PCI
Express connectors. These connectors
are found on almost every new PC motherboard,
but they aren’t used for PCI
Express. Instead, they provide a bus backplane
for MCF51CN interfaces.
The approach allows for very inexpensive
two-layer boards, including the
MCU Module and the Peripheral Module,
which includes connectors for various
interfaces. The first “elevator” is used
for signal distribution,
while the second
“elevator” board
provides physical
stability.
The system’s
architecture makes
it easy for designers
to add boards, including
custom interface boards. Software
includes a 64-kbyte code limited version
of Freescale’s CodeWarrior toolset that
supports the MQX operating system and
Ethernet stack.
The MCF51CN has a 50-MHz, 32-bit
ColdFire core with 128 kbytes of flash
and 24 kbytes of RAM. The external
bus interface supports up to 2 Mbytes
of off-chip storage. It also has a built-in
10/100 Ethernet interface with an internal
media access controller (MAC)
using an external physical layer (PHY).
Peripherals include a 12-bit, 12-channel analog-to-digital converter (ADC), three
serial communications interface (SCI)
serial ports, two serial peripheral interface
(SPI) ports, two I2C ports, and 70
general-purpose I/O (GPIO).
At $2.99, the MCF51CN is a relatively
inexpensive chip so the $99 kit is a good
match. Freescale has taken an interesting
approach with its development kit. Following
the old axiom, “Keep it simple,”
Freescale has a winner.
BILL WONG
FREESCALE SEMICONDCTOR
www.freescale.com