User manual

21 GR-LEON4-ITX Development Board
User Manual
2.17 Debug Support Unit Interfaces
Program download and debugging to the processor is performed using the GRMON Debug
Monitor tool from Aeroflex Gaisler (RD-5). The LEON4 ASIC provides a interface for Debug
and control of the processor by means of a host terminal via its DSU interface, as
represented in Figure 2-16.
Three control signals and a data connection form the Debug Support Unit interface to the
processor:
DSUEN: This signal is pulled high on the board to enable Debugging
DSUBRE: The push-button forces the processor to halt and enter DSU mode.
DSUACT: When the processor is halted, the LED will illuminate
To communicate with the processor, four possibilities for the data connection to the
processor are provided:
SERIAL DSU Serial Debug Communication Link (connector J12)
JTAG-DCL JTAG Debug Communication Link (connector J19 or J20)
USB-DCL USB Debug Communication Link (connector J6)
EDCL Ethernet Debug Communication Link (connector J3)
GRMON can be used with the above listed interfaces, for more information, please refer to
RD-5 and RD-6.
© Aeroflex Gaisler AB August 2010, Rev. 0.3
Figure 2-16: Debug Support Unit connections
LEON4
ASIC
DSUBRE→
DSU I/F
HOST
TERMINAL/COMPUTER
JTAG
JTAG I/F
EDCL
USB-DCL
SERIAL
DSUACT ←
DSUEN
→