MOTOROLA
Chapter 24. READI Module
24-7
Terms and Definitions
Data Read Message
(DRM)
External visibility of data reads to internal memory-mapped resources.
Data Write Message
(DWM)
External visibility of data writes to internal memory-mapped resources.
Data Trace Messaging
(DTM)
External visibility of how data flows through the embedded system. May include DRM and/or
DWM.
Download
Tool sends information to the device
Field
Number of bits representing single piece of information
FPM
Full Port Mode. This is the default full port mode for READI.
IEEE-ISTO 5001
IEEE-ISTO 5001, formerly known as Global Embedded Processor Debug Interface Standard.
Halt
RCPU is in freeze state (typically in debug mode)
Instruction Fetch
The process of reading the instruction data received from the instruction memory.
Instruction Issue
The process of driving valid instruction bits inside the processor. The instruction is decoded
by each execution unit, and the appropriate execution unit prepares to execute the instruction
during the next clock cycle.
Instruction Taken
An instruction is taken after it has been issued and recognized by the appropriate execution
unit. All resources to perform the instruction are ready, and the processor begins to execute it.
Instruction Retire
Completion of the instruction issue, execution and writeback stages. An instruction is ready
to be retired if it completes without generating an exception and all instructions ahead of it in
history buffer have completed without generating an exception.
ICTRL
Instruction bus support control register (Refer to
Table 23.6.11)
Ownership Trace
Message (OTM)
Visibility of process/function that is currently executing.
Public Messages
Messages on the auxiliary signals for accomplishing common visibility and controllability
requirements e.g. DRM and DWM.
RCPU
Processor that implements the PowerPC-based architecture used in the Motorola MPC500
family of microcontrollers.
READI
Real time Embedded Applications Development Interface.
READI signals
Refers to IEEE-ISTO 5001 auxiliary port.
RPM
Reduced Port Mode. This is the reduced port mode for READI.
run-time
RCPU is executing program code in normal mode
Sequential Instruction
Any instruction other than a flow-control instruction or isync.
Snooping
Monitoring addresses driven by a bus master to detect the need for coherency actions.
Standard
The phrase “according to the standard” implies according the IEEE-ISTO 5001 - 1999.
Superfield
One or more message “fields” delimited by MSEO/MSEI assertion/negation.
The information transmitted between “start-message” and “end-packet” states.
Table 24-3. Terms and Definitions (continued)
Term
Description