72
AT94KAL Series FPSLIC
Rev. 1138G–FPSLI–11/03
The Breakpoint Unit implements Break on Change of Program Flow, Single Step Break, 2 Pro-
gram Memory Breakpoints, and 2 combined break points. Together, the 4 break-points can be
configured as either:
•
4 single Program Memory break points
•
3 Single Program Memory break point + 1 single Data Memory break point
•
2 single Program Memory break 2 single Data Memory break points
•
2 single Program Memory break 1 Program Memory break point with mask
(‘range break point’)
•
2 single Program Memory break 1 Data Memory break point with mask (‘range
break point’)
•
1 single Frame Memory break point is available parallel to all the above combinations
A list of the On-Chip Debug specific JTAG instructions is given in “On-chip Debug Specific
JTAG Instructions”. Atmel supports the On-Chip Debug system with the AVR Studio front-end
software for PCs. The details on hardware implementation and JTAG instructions are there-
fore irrelevant for the user of the On-Chip Debug system.
The JTAG Enable bit must be set (one) in the System Control Register to enable the JTAG
Test Access Port. In addition, the On-chip Debug Enable bit must be set (one).
The AVR Studio enables the user to fully control execution of programs on an AVR device with
On-Chip Debug capability, AVR In-Circuit Emulator, or the built-in AVR Instruction Set Simula-
tor. AVR Studio supports source level execution of Assembly programs assembled with Atmel
Corporation’s AVR Assembler and C programs compiled with third-party vendors’ compilers.
AVR Studio runs under Microsoft Windows
®
95/98/2000 and Microsoft WindowsNT
®
.
All necessary execution commands are available in AVR Studio, both on source level and on
disassembly level. The user can execute the program, single step through the code either by
tracing into or stepping over functions, step out of functions, place the cursor on a statement
and execute until the statement is reached, stop the execution, and reset the execution target.
In addition, the user can have up to 2 data memory breakpoints, alternatively combined as a
mask (range) break-point.