E2, IE850A
5. Notes on Usage
R20UT4140EJ0300 Rev.3.00
Page 32 of 41
Oct.09.20
5.4.15 Masking of interrupts while the emulator is in use
Table 5-2 shows the states of a device while the emulator is in use and the operation of interrupts (EIINT,
FEINT, or FENMI). During single stepping, interrupts are masked to emulate each line of source code of the
program in non-realtime. When interrupt processing is to be stepped through, set a breakpoint at the
beginning of the interrupt processing and generate an interrupt during execution of the user program. A break
will then be generated at the beginning of the interrupt processing. In C-source-level stepping, resets are
masked in different ways depending on the debugger; one method is to use single stepping and another is to
set a temporary breakpoint and execute the user program. Accordingly, this document cannot define enabling
and disabling of reset masking per debugger; refer to the manual for the debugger you are using.
Table 5-2 State of a Device and Masking of Interrupts
State of a device
In breaks
In single
stepping
In user program execution
In C-source-level
stepping
Interrupt masked*
Interrupt masking disabled
(operation according to the
specification of the user
system)
Depends on the debugger
•
An interrupt generated in the state marked (*) in Table 5-2 is kept pending and interrupt processing
proceeds after interrupt masking is canceled.
5.4.16 Rewriting of on-chip flash memory (working RAM)
When the debugger performs any operation that involves programming of the flash memory* during a break,
part of the internal RAM area is used as a working RAM area. The 4-KB area from the last address of the local
RAM (self) area of CPU0 are initially set as the working RAM area.
The debugger can change the working RAM area. After the debugger has saved the values from the working
RAM area and rewrites the flash memory, it restores the saved values to the working RAM area. To guarantee
the values, it is required to set an area to which there will be no access by the DMAC or any external master
to the working RAM area so that operation may continue even if the device enters the break state.
Note: Rewriting of flash memory proceeds in response to any of the operations below.
•
Downloading to on-chip flash memory
•
Changes to on-chip flash memory by using the [Memory] panel or the [Disassemble] panel
•
Setting or cancellation of software breaks
•
Re-execution after a software break is encountered (including stepped execution)
