Xilinx ChipScope Pro, User Manual

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ChipScope Pro Software and Cores User Guide www.xilinx.com 131
UG029 (v14.3) October 16, 2012
Chapter 5
ChipScope Engine Tcl Interface
Overview
This interface provides Tcl scripting access to JTAG (Joint Test Action Group, IEEE
standard) download cables using the communication library in the ChipScope™ logic
analyzer engine. The purpose of the CSE/Tcl interface is to provide a simple scripting
system to access basic JTAG, FPGA, and VIO (virtual input/output) core functions. In a
few lines of Tcl script, you can scan and manipulate devices in the JTAG chain (and VIO
cores in those devices) through standard Xilinx® JTAG cables.
For further information on JTAG, see Configuration and Readback of Virtex FPGAs Using
(JTAG) Boundary Scan [See Reference 12, p. 225] . For information about Tcl, see Tcl
Developer Xchange [See Reference 26, p. 226] .
Requirements
•
A computer system running one of the supported operating systems described in the
ISE Design Suite Release Notes Guide [See Reference 14, p. 225] .
•
A supported JTAG cable such as Platform Cable USB, Parallel Cable IV, or Parallel
Cable III.
•
A Tcl shell (
xtclsh
is provided in the ChipScope Pro and ISE® tool installations) or
the ActiveTcl 8.4 shell [See Reference 24, p. 226] .
•
The required environment variables are set up by using
xtclsh.exe
(on Windows)
or
xtclsh
(on Linux).
Limitations
The ChipScope Engine Tcl interface package favors simplicity over performance. Some
commands such as
::chipscope::csejtag_tap_shift_chain_ir
and
::chipscope::csejtag_tap_shift_chain_dr
transfer bits as hexadecimal strings
(for example, "
30010A7
") instead of as packed binary data structures. The extra overhead
in converting particularly large data strings does result in some loss of performance;
however, the simple design of the application programming interface (API) and the use of
the Tcl scripting language makes CSE/Tcl an easy-to-use means to interact with devices
and cores in the JTAG chain.
Note:
The CSE/Tcl interface is only compatible with software that uses the CSE/Tcl interface to the
JTAG cable communication device (such as the ChipScope Pro Analyzer tool and the Embedded
Development Kit (EDK) XMD software debugger tool).