Once Module Signals; Introduction; Figure 10-1 Once Module Block Diagram - Motorola DSP56305 User Manual

10.1

INTRODUCTION

The DSP56300 core On-Chip Emulation (OnCE™) module provides a means of
unintrusive interaction with the DSP56300 core and its peripherals. The OnCE module
allows the user to examine registers, memory, or on-chip peripherals, thus facilitating
hardware and software development on the DSP56300 core processor. Special circuits
and dedicated signals on the DSP56300 core are defined to avoid sacrificing any
user-accessible on-chip resource. The OnCE module resources can be accessed only after
executing the JTAG instruction ENABLE_ONCE. See Section 11, JTAG Port, for a
description of the JTAG functionality and its relation to the OnCE. Figure 10-1 shows the
block diagram of the OnCE module.
PDB PIL GDB
Pipeline
Information
XAB
YAB
PAB
Trace
Buffer
10.2

OnCE MODULE SIGNALS

The OnCE module controller functionality is accessed through the JTAG Test Access
Port (TAP). There are no dedicated OnCE module signals for clock, data in, or data out.
The JTAG signals TCK, TDI, and TDO are used to shift data and instructions in and out.
See JTAG Signals on page 11-5 for the description of the JTAG signals. To facilitate
emulation-specific functions, one additional signal, called DE, is provided on the
DSP56305.
MOTOROLA
Control Bus
Breakpoint
Tags
Buffer

Figure 10-1 OnCE Module Block Diagram

DSP56305 User's Manual
Trace Logic
OnCE
Controller
Logic
On-Chip Emulation Module
Introduction
TCK
TDI
TDO
TRST
DE
AA0702
10-3