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MCF5249UM
MOTOROLA
MCF5249 Functional Overview
be generated on the rising or falling edge of the pin. All interrupts are autovectored and interrupt levels are
programmable.
1.6.23
JTAG
To help with system diagnostics and manufacturing testing, the MCF5249 includes dedicated
user-accessible test logic that complies with the IEEE 1149.1A standard for boundary scan testability,
often referred to as Joint Test Action Group, or JTAG. For more information, refer to the IEEE 1149.1A
standard. Motorola provides BSDL files for JTAG testing.
1.6.24
SYSTEM DEBUG INTERFACE
The ColdFire processor core debug interface supports real-time instruction trace and debug, plus
background-debug mode. A background-debug mode (BDM) interface provides system debug.
In real-time instruction trace, four status lines provide information on processor activity in real time (PST
pins). A four-bit wide debug data bus (DDATA) displays operand data and change-of-flow addresses,
which helps track the machine’s dynamic execution path.
1.6.25
CRYSTAL AND ON-CHIP PLL
Typically, an external 16.92 Mhz or 33.86 Mhz clock input is used for CD R/W applications, while an
11.2896 MHz clock is more practical for Portable CD player applications. However, the on-chip
programmable PLL, which generates the processor clock, allows the use of almost any low frequency
external clock (5-35 Mhz).
Two clock outputs (MCLK1 and MCLK2) are provided for use as Audio Master Clock. The output
frequencies of both outputs are programmable to Fxtal, Fxtal/2, Fxtal/3, and Fxtal/4. The Fxtal/3 option is
only available when the 33.86 Mhz crystal is connected.
The MCF5249 supports VCO operation of the oscillator by means of a 16-bit pulse density modulation
output. Using this mode, it is possible to lock the oscillator to the frequency of an incoming IEC958 or IIS
signal. The maximum trim depends on the type and design of the oscillator. Typically a trim of +/- 100 ppm
can be achieved with a crystal oscillator and over +/- 1000 ppm with an LC oscillator.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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