Datasheet

Platform Cable USB
DS300 (v3.3) June 25, 2014 www.xilinx.com
Product Specification 6
R
In Boundary-Scan mode, iMPACT 7.1i (and later) queries
the BSDL file of each device in a target Boundary-Scan
chain to determine the maximum Boundary-Scan clock
(JTAG TCK) frequency. iMPACT 7.1i (and later)
automatically restricts the available TCK_CCLK_SCK
selections to frequencies that are less than or equal to the
slowest device in the chain. By default, iMPACT 7.1i (or
later) selects either 6 MHz or the highest common
frequency when any device in the Boundary-Scan chain is
not capable of 6 MHz operation. Tabl e 2 shows the
maximum supported JTAG TCK frequency for a variety of
Xilinx devices. See the device data sheet or BSDL file for
maximum JTAG TCK specifications.
Note:
iMPACT versions earlier than 7.1i do not restrict the
TCK_CCLK_SCK selections in Boundary-Scan mode.
Accordingly, users should take care to select a TCK_CCLK_SCK
frequency that matches the JTAG TCK specifications for the
slowest device in the target Boundary-Scan chain.
A Status bar on the bottom edge of the iMPACT GUI
provides useful information about operating conditions. If
the host port is USB 1.1, Platform Cable USB connects at
full-speed, and the Status bar shows "usb-fs." If the host
port is USB 2.0, Platform Cable USB connects at Hi-Speed
and the Status bar shows "usb-hs."
The active TCK_CCLK_SCK frequency is shown in the
lower right-hand corner of the Status bar (see Figure 10).
The command log also includes information about
communication with the cable. When the cable is selected
using the Cable Communication Setup dialog box, the
command log indicates:
Firmware version = 1
CPLD file version = 0004h
CPLD version = 0004h
Cable Connection Established
Note: The actual revision number can be expected to change
with new software releases.
Status Indicator
Platform Cable USB uses a bi-color Status LED to indicate
the presence of target voltage. When the ribbon cable is
connected to a mating connector on the target system, the
Status LED is illuminated as a function of the voltage
present on pin 2 (V
REF
).
Users must design their system hardware with pin 2
attached to a voltage plane that supplies the JTAG, SPI, or
slave-serial pins on the target device(s). Some devices have
separate power pins for this purpose (VAUX), while others
have a common supply for both VCCIO and the JTAG pins
(TCK, TMS, TDI, and TDO). Refer to the target device Data
Sheet for details on slave-serial or JTAG pins.
The Status LED is amber (see Figure 11) when any one or
more of the following conditions exist:
• The ribbon cable is not connected to a target system
• The target system is not powered
• The voltage on the V
REF
pin is < +1.5V
The Status LED is green when all of the following
conditions exist:
• The ribbon cable is connected to a target system
• The target system is powered
• The voltage on the V
REF
pin is ≥ +1.5V
The Status LED is Off whenever Platform Cable USB enters a
Suspend state, or is disconnected from a powered USB port.
Tabl e 2: Maximum JTAG Clock Frequencies
Device Family
Maximum JTAG
Clock Frequency
Units
XC9500/XL/XV 10 MHz
XPLA3 10 MHz
CoolRunner-II 33 MHz
XC18V00 10 MHz
XCF00S/XCF00P 15 MHz
Virtex 33 MHz
Virtex-II 33 MHz
Virtex-II Pro 33 MHz
Virtex-4 33 MHz
Virtex-5 33 MHz
Spartan 5 MHz
Spartan-II 33 MHz
Spartan-3 33 MHz
Spartan-3A 10 MHz
Spartan-3E 10 MHz
X-Ref Target - Figure 10
Figure 10: iMPACT Status Bar
DS300_10_111904
Active Cable
Identification
Full-Speed or
High-Speed
Connection
Active
TCK_CCLK
Frequency
Command Log
Text Display