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P5040/P5020 Reference Design Board User Guide, Rev. 0
32
Freescale Semiconductor
Architecture
5.2.1
CONFIG
CONFIG monitors and/or sets selected configuration signals, per the following examples.
•
CONFIG can, in some instances, map switch settings into direct configuration outputs.
•
For SYSCLK, it maps a 3-position switch into a 16-bit register initialization pattern that is
subsequently used to initialize the clock generator.
5.2.2
COP JTAG
COP JTAG handles, in a transparent manner, the merging of COP header resets with onboard resets.
•
It is critical that COP_ HRST input reset the entire system
EXCEPT
for the COP JTAG controller;
for example, TRST must not be asserted.
•
If COP JTAG is not connected to P5040/P5020RDB, then it is critical that reset assert TRST.
The COP core manages these modal operations.
5.2.3
LOCALBUS
LOCALBUS is the interface between processor and REGFILE; asynchronous signaling is used since
access to the internal registers may be blocked.
5.2.4
REGISTERS
REGFILE is a dual-port register file that contains several types of registers.
NOTE
REGFILE must be able to accept (or arbitrate for) concurrent writes to the
same register. This, however, is not a statistically likely occurrence.
5.2.5
REGRESETS
REGRESETS copies sequencer reset signals and allows register-based software to individually assert reset
to the local bus, memory, and/or compact FLASH interfaces.
5.2.6
RESETSEQ
RESETSEQ collects various reset/power good signals and initiates the global reset sequencer.
Register Resets
Drives resets from one of the following: sequencer, register-based software control,
or VELA.
Reset Sequence
Collects various reset/power-good signals and starts the global reset sequencer.
Table 17. ngPIXIS Features (continued)
Feature
Description