Renesas IE850A User Manual page 28

E2, IE850A
the initially stopped state following release from a reset and applications that include use of the standby mode
of devices can be synchronously debugged. For details of the method, refer to the relevant application note
(R20AN0577EJ0100).
5.3.6 Setting the STMSEL1 bit of OPBT3
When STMSEL1 is set to 1 and the emulator is not connected (TRST = low), the device enters the serial
programming mode. When the emulator is connected (TRST = high), the device enters the normal operating
mode or user boot mode (for details, refer to the user's manual for the target device). When STMSEL1 is set
to 1 and the emulator is not connected, the device enters the serial programming mode and does not start
execution of the user program.
5.3.7 Power off standby mode
The emulator does not support emulation of power off standby. Check the operation of the power off standby
when the emulator is not connected.
5.3.8 BIST
BIST is skipped when the emulator is connected (TRST = high).
5.3.9 Reading registers with undefined initial values and an ECM error
Reading a register with undefined initial values, such as the EIPC and general-purpose registers when they
have not been initialized, leads to different values being read by the master CPU and checker CPU, which is
detected as an error by the error control module (ECM).
After the debugger is started (exclusive of the case of a hot plug-in connection), the debugger internally
initializes the EIPC and general-purpose registers. Thus, if you have forgotten to initialize these registers in
the user program, there is a difference between the connected and non-connected states in that an ECM error
does not occur when the emulator is connected but does occur when the emulator is not connected.
Be sure to initialize and read registers with undefined initial values in the user program.
The debugger saves the EIPC and general-purpose registers whenever a break occurs and restores the
saved values before execution of the user program is restarted. If a break occurs when these registers have
not been initialized, an ECM error will occur due to processing for saving by the debugger.
5.3.10 VMON reset
When an emulator is connected (TRST = high), the VMON reset cannot be emulated.
R20UT4140EJ0300 Rev.3.00
Oct.09.20
5. Notes on Usage
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