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DSP56800E Core Description
MOTOROLA
Overview
1-21
Preliminary
1
clearing, or inverting individual or multiple bits within a 16-bit word. The
bit-manipulation unit can also test bytes for branch-on-bit field instructions.
1.4.11 Enhanced On-Chip Emulation (EOnCE) Module
The Enhanced On-Chip Emulation (EOnCE) module allows user interaction in a debug
environment with the DSP56800E core and its peripherals. Its capabilities include:
Examining registers
Memory, or on-chip peripherals
Setting breakpoints in memory
Stepping or tracing instructions
It provides simple, inexpensive, and speed independent access to the DSP56800E core for
sophisticated debugging and economical system development. The JTAG port allows
access to the Enhanced OnCE module and through the DSP5685x device to its target
system, retaining debug control without sacrificing other user accessible on-chip
resources. This technique eliminates the costly cabling and the access to processor pins
required by traditional emulator systems. The Enhanced OnCE interface is fully described
in the DSP56800E Reference Manual (DSP56800EUM/D).
1.4.12 Clocks
1.4.12.1 On-Chip Clock Synthesis Block
The clock synthesis module generates the clocking for the DSP5685x family of devices. It
generates the master clock used by the System Integration Module (SIM) to derive the
system and peripheral clocks. It also generates the time of day clock used by time-based
modules like TOD and COP. It contains an oscillator module to apply the clock. It also
contains a PLL with the ability to multiply-up the frequency. The PLL can also be
bypassed and scaled to lower power consumption on the DSP5685x device. The CGM
module selects which clock is routed to the master clock output. It also selects and
configures the time of day clock prescaler and PLL.
1.4.12.2 Oscillator
The DSP5685x device is clocked either from an external crystal or external clock input:
Crystal oscillator uses a 2 - 4MHz crystal
Ceramic resonator can be used in place of the crystal
There are separate power and ground for the oscillator and PLL
Oscillator input can be directly clocked at up to 240MHz