E30A Emulator User
’s Manual
4. Debugging Functions
R20UT0422EJ0501 Rev.5.01
Page 44 of 65
Mar 15, 2016
4. Debugging Functions
4.1 Break Function
4.1.1 Software Break
If the breakpoint you set is a software breakpoint, the program stops before executing the instruction at the set breakpoint
- Up to 256 break points can be set.
- You can specify breakpoints in the internal RAM of the MCU, the internal flash ROM of the MCU, and the RAM on the
user system.
- If breakpoints in the internal flash ROM of the MCU are specified, the need arises for instruction rewrite/writeback
processing in block units.
4.1.2 Execution Address Break
This is a kind of event break by the internal debug circuit of the MCU. It specifically is a pre-execution break that causes
execution of the user program to stop at a specified address.
-
Up to 8 break points can be set (used for hardware breaks, trace points, and time measurement events in common).
-
Since there is no need for instruction rewrite/writeback processing, the response speed is fast.
4.1.3 Hardware Break
This is a kind of event break by the internal debug circuit of the MCU. It specifically is a post-execution break that causes
execution of the user program to stop upon detecting data access at a specified address.
-
Up to 8 break points can be set (used for execution address breaks, trace points, and time measurement events in common).
-
You can set a specified address range (using 2 events).
-
You can set three conditions, e.g., read, write, and read/write.
-
Only one instance of data comparison break can be specified (event E5 only). Several bytes from the beginning of the
MCU’s internal RAM (8 bytes at the addresses 0400h -- 0407h) are used for data comparison by the debug monitor program.
These bytes cannot be used in the user program when using a data comparison break.
Notes on Execution Address Break and Hardware Break:
Do not set breaks in the area designated below. This restriction is due to specifications of the MCU’s
internal debug circuit.
0100 0000h
– FEFF FFFFh
Note on Data Comparison Break:
For data comparison break, the debug monitor program compares the data after the debug interrupt
occurs at the specified address to determine whether or not to cause a break. Using this function results
in the realtime capability becoming impaired because the debug monitor program intervenes. Also, in
order to complete processing of the debug monitor program as fast as possible, do not operate the
MCU’s internal DMA during the processing.
In the case of X
IN
8MHz, PLL 128MHz (16 times), BASE 64MHz and CPU 64MHz, for example, it takes
6
μs to return to the user program after the data comparison results in a mismatch.
4.1.4 Break Combination
Event breaks by the internal debug circuit of the MCU can be cascaded to constitute a state transition break at up to 8 points in
the forward direction. If all of the events are used for a state transition break, program execution will break when the events E7,
E6, ..., and E0 all have occurred in that order.
