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DESIGNING WITH THE MMC2107

by David Gonzales

Start ý System Overview ý On-Chip Memory Arrays ý Receiving and Servicing Real-Time Interrupts ý Asynchronous and Synchronous Communication ý Measuring, Timing, Creating ý Collecting Analog Information ý System Features ý Sources and PDF

SYSTEM FEATURES

Other considerations can increase the reliability of your system and help increase the battery life in portable applications. For example, if your application operates in harsh environments, the circuitry may periodically receive high voltages or mechanical shock that may cause your system to stall or get lost. A watchdog timer helps your application program continue to operate properly.

System reset, power management, external memory interface, and debugging are also important functions. There are six sources of reset including power-on reset, external reset, software reset, loss of clock reset, loss of PLL lock reset, and watchdog timer reset. There are three low-power modes of operation, which allow powering down particular peripherals until an interrupt service from the peripheral is required. A programmable on-chip PLL permits the system frequency to be scaled dynamically.

A full 32-bit external bidirectional data bus with a 23-bit address bus and four chip select signals provides an interface to external memories or circuits. If the external bus is not needed, the pins may be used as general-purpose I/O lines.

Having a host of resources on a single chip reduces visibility of their interaction with the processor, so some sort of debug hooks are needed to help designers during hardware/software integration. A JTAG interface to a OnCE debug port provides source level debugging and direct access to all on-chip resources in your application. Internal bus activity may be brought out via a show cycle mode for direct hookup to your Tektronix or Agilent logic analyzer. Software development tools are available from Metrowerks and Wind River Systems that permit C/C++ coding and debugging of application programs.

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