BH-EMU-JACK Blackhawk, BH-EMU-JACK Datasheet

Programming Accessories OMAP JTAG Adapter

BH-EMU-JACK

Manufacturer Part Number

BH-EMU-JACK

Description

Programming Accessories OMAP JTAG Adapter

Manufacturer

Blackhawk

Datasheet

1.BH-EMU-JACK.pdf (2 pages)

Specifications of BH-EMU-JACK

Product

Calibration Tool

Lead Free Status / RoHS Status

Lead free / RoHS Compliant

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Probing TCK and RTCK

The output (TCK) and return (RTCK) test

clocks are easily accessible via the target

board’s JTAG header on pin 11 (TCK) and

pin 9 (RTCK). Attaching oscilloscope probes

to these pins will give you the ability to view

the clock synchronization with and without the

adapter in place.

Figure 6 below shows the output of the test

clock signals using an emulator that does not

handle the adaptive clocking feature of the TI

OMAP cores.

For this example, measurements were made

with the emulator connected to an OSK5912

as the target board. You can see that the

clocks are not synchronized, which can lead

to data corruption and reduced performance.

Figure 7 shows the output from the same

clock signals, using the same emulator con-

nected to the same OSK5912 target board.

The only difference is that we inserted the

JACK between the target board’s JTAG

header and the JTAG connector of the emula-

tor.

This shows that, without changing the emula-

tor, target board, or any settings, the clock

edges are fully synchronized. The TCK sig-

nal is adapting to the changes in RTCK from

the OMAP device’s core clock.

Solving the TRST Issue with the TI XDS510

XDS510-class emulators that depend on the TI SN74ACT8990 test bus controller (TBC) to assert

the TRST signal are susceptible to a dead-lock condition with certain OMAP cores that stop

RTCK when TRST is asserted. Because these cores stop RTCK, the TBC enters a suspended

state, never updates, and will not clear the asserted TRST signal.

To solve this issue, the adapter board will route TCK to RTCK if it detects RTCK has stopped

when TRST is asserted (see Figure 3). You will find that the TI XDS510 ISA card and other TBC-

based emulators will now work with all OMAP devices when this adapter kit is being used.

XDS560-class emulators, which do not rely on the TBC for asserting TRST, will not be affected by

the JACK’s TRST logic.

Signal Analysis

Blackhawk

123 Gaither Drive

Mt. Laurel, NJ 08054-1701

www.blackhawk-dsp.com

+1-877-983-4514

Blackhawk is a registered trademark of EWA Technologies, Inc.

BH-Jack-QS-01

Figure 6—Non-adaptive clocking Emulator

Figure 7—Adaptive Clocking Emulator

Overview

The JTAG Adaptive Clocking Kit (JACK), shown in

figure 1, is designed to allow JTAG emulators for TI

DSPs to synchronize with the adaptive clocking cores

of Texas Instruments OMAP™ devices providing com-

plete data integrity and increased performance.

What is Adaptive Clocking?

Adaptive clocking is a feature of synthesizable cores,

introduced by ARM

OMAP platform, wherein the input test clock (TCK) is delayed and synchronized with the core clock

before producing the output clock (RTCK). Emulators need to adapt to this changing RTCK signal.

During this delay (synchronizing period) the target core samples Test Data In (TDI), Test Mode

Select (TMS), and TCK with the core clock. This delay is variable and changes in real time, which

can cause data corruption.

Figure 2 shows an example of this

synchronizing mechanism inside the

OMAP processor core. Here you can

see the multi-stage synchronizer

consisting of several D-triggers,

which is dependant on the core clock

rate.

Figure 3 illustrates the JACK logic to

handle these real time changes to

RTCK. The resulting logic will main-

tains synchronization with the JTAG

signals as the rate of the OMAP core

clock changes.

You may find emulator release notes

that

(workarounds) that are necessary to

operate with these TI OMAP adaptive

clocking cores. This usually involves

decreasing the output TCK rate of the

emulator.

correct the problem, the data and

clock signals will still not be synchro-

nized with the OMAP core clock and

you will only decrease performance.

Compatibility

This JACK is designed to be compatible with the traditional 14-pin emulators supporting the com-

mon JTAG functions and signals. This includes XDS510™-class and XDS560™-class emulators.

The JACK will also work when connected to non-adaptive clocking targets.

QUICK

START

GUIDE

describe

While this may seem to

setup

Ltd. and adopted by TI in their

changes

Blackhawk™ JTAG

Adaptive Clocking

Kit for OMAP™

Figure 2—OMAP Adaptive Clocking Mechanism

Figure 3—JACK Adaptive Clocking Logic

Figure 1 - JACK hardware

Part No. BH-EMU-JACK

Related parts for BH-EMU-JACK

BH-EMU-JACK Summary of contents

Page 1

... This JACK is designed to be compatible with the traditional 14-pin emulators supporting the com- mon JTAG functions and signals. This includes XDS510™-class and XDS560™-class emulators. The JACK will also work when connected to non-adaptive clocking targets. Figure 1 - JACK hardware Part No. BH-EMU-JACK 1 ...

Page 2

... GND • 9 RTCK 10 GND Blackhawk is not responsible for any damage that may occur to the JACK, target board, or emulator if misused, mishandled, or forced into place. 11 TCK 12 GND • The JACK is not intended to be hot pluggable, damage may occur. Make sure you emulator and target board are not powered when making connections ...

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