EOnCE Enabling and Power Considerations

Table 4-5. EOnCE Event and Action Summary

Event type

Counted

trace

Debug

Debug

Enable

Disable

Other actions

trigger

state

exception

tracing

tracing

 

 

 

Clock

+

-

-

-

-

-

 

 

 

 

 

 

 

Trace Transaction

+

-

-

-

-

-

 

 

 

 

 

 

 

EC

+

-

-

-

-

-

 

 

 

 

 

 

 

MARK

-

+

-

-

-

-

 

 

 

 

 

 

 

COF

-

+

-

-

-

-

4.4 EOnCE Enabling and Power Considerations

Except for the EOnCE controller, modules are disabled until one of the following occurs:

Write access is made to one of the EOnCE registers by the core software.

Execution of either ENABLE_EONCE or DEBUG_REQUEST instructions by the host These events enable all the EOnCE modules, which will result in increased power consumption.

4.5 EOnCE Module Internal Architecture

The EOnCE module is composed of five main sub-units, which performs the following main tasks:

EOnCE Controller: Controls the overall behavior of the EOnCE and allows the JTAG port and core software to read and write the EOnCE registers

Event Counter: Counts various events

Event Detection Unit (EDU): Generates events when it detects predefined values on

the data-memory address buses

the program counter

the data-memory data buses

Event Selector: Controls what action is taken when events or a combination of simultaneous events occurs

Trace Unit: Performs non-intrusive program tracing during program execution

The various EOnCE units include a number of registers. The units, the tasks they perform, and the corresponding registers are described in the sections that follow.

4.5.1 EOnCE Controller

The EOnCE controller performs the following functions:

Reading and writing EOnCE registers through JTAG

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SC140 DSP Core Reference Manual

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Freescale Semiconductor SC140 specifications EOnCE Enabling and Power Considerations, EOnCE Module Internal Architecture