702560 Spectrum Digital Inc, 702560 Datasheet - Page 32

• Manufacturer Part Number: 702560
• Description: XDS560R USB JTAG Emulator With 20 Pin CTI JTAG Header
• Manufacturer: Spectrum Digital Inc
• Type: USB JTAG Emulatorr

Specifications of 702560

• Contents: Board, Cable
• Ic Product Type: USB JTAG Emulator
• Kit Contents: XDS560R USB JTAG Emulator With CTI JTAG Header, CDROM With Drivers, USB Cable
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: TI DSPs and JTAG Microcontrollers
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Spectrum Digital, Inc
3.6 EMU0-EMU1 Signal Considerations
3-14
The EMU0-EMU1 signals are bi-directional multifunctional signals. These signals are
used for software benchmarking and software profiling.
On multi-processor systems, they can be used to assist in debugging by causing an
interrupt or breakpoint to occur from one device to another. These signals are used for
HS-RTDX (High-Speed Real Time Data eXchange).
HS-RTDX is a form of bi-directional data transfer.
Each EMU signal supports a single channel of data transfer.
This form of communication uses TCK and the EMU0 and/or EMU1 to achieve up to
2 Megabytes/second transfer rate. Also, the EMU0-EMU1 signals may be used to
select different modes of the device.
These modes are set when the device RESET signal is release, for normal emulation
the EMU0-EMU1 signal should be pulled high to the device Input/Output voltage.
For designs with target devices that don’t support HS-RTDX the only requirement is
that it is necessary to ensure that the EMU0-EMU1 lines can go from a logic low level
to a logic high level in less than 10 us. This can be calculated using the formula in
Equation 3-3:
Equation 3-3. Calculating EMU0-EMU1 Lines That Don’t Support HS-RTDX
For designs with target devices that support HS-RTDX, the requirements are the same
for a low number of devices. But as the number devices increases the response of the
EMU0-EMU1 signal will increase which will require the user to reduced the TCK
frequency.
To maximize the TCK rate, the user will be required to manually adjust the TCK
frequency and run the HS-RTDX confidence tests until a frequency is found where the
HS-RTDX confidence tests pass reliability.
It is suggested that after a frequency is found, that the user reduce the frequency by
additional 10% to guarantee that temperature and environmental changes don’t affect
the operation of the emulator.
For some multi-processor designs crossbar technology (CBT) devices could be used to
break the number of devices into a bank of devices.
t
r
= 5 (R
= 5(4.7KW x 16 15pf)
= 5.64 us.
pullup
x N
devices
x C
load_per_device
XDS560R JTAG Emulator Installation Guide
)