Renesas M16C/6N4 Network Card User Manual


 
M306NKT-EPB User’s Manual 4. Hardware Specifications
REJ10J0519-0200 Rev.2.00 Oct. 16, 2006 Page 93 of 104
IMPORTANT
Note on the Watchdog Function:
z If the reset circuit of the user system has a watchdog timer, disable it when using the emulator.
Note on Protect Register:
z The protect is not canceled when bit 2 of protect register PRCR (PRC2), which enables writing into the ports P7
and P9 direction registers and the SI/Oi control register, is changed with the below procedure.
(1) Step execution of an instruction setting PRC2 to "1"
(2) Execution from the instruction setting "1" to PRC2 where a software breakpoint is set
(3) Setting a break point between an instruction setting PRC2 to "1" and a point where the ports P7 or P9
direction registers or the SI/Oi control register is set
(4) Setting PRC2 to "1" by the memory window or script window
Note on Access Prohibited Area:
z You cannot use internally reserved areas. Write signals to the areas will be ignored, and values read will be
undefined.
Note on Breaks:
z The area displaying break points in the program window of the emulator debugger shows the following breaks.
(1) Address-match break
This is a debugging function which breaks a program, using the address-match interrupt function of the
MCU, immediately before the system executes an instruction at a specified address. The instruction at the
preset address will not be executed.
(2) Software break
This is a debugging function which generates a BRK interruption by changing an instruction at a specified
address to a BRK instruction (00h) to break a program immediately before the system executes an
instruction at a specified address. The instruction at the preset address will not be executed.
(3) Hardware break
This is a debugging function which breaks a program by setting the detection of an execution of an
instruction at a specified address as a break event. The program will break after the instruction at the
specified address is executed.
Notes on Software Breaks:
z Software breaks change the instruction at a specified address to a BRK (00h). Therefore, take note that when
you reference the result of a trace in bus mode, "00h" is displayed.
z The BRK instruction can be used for the emulator only. You cannot use it in a user program.
z You can neither set nor cancel a software breakpoint in the internal ROM area of an MCU during user program
execution, while you can set or cancel it in the internal RAM area of an MCU or an area where chip select CS3#
to CS0# are set to INTERNAL (emulation memory).
Notes on Address-Match Breaks:
z As the processing speed of setting and canceling address-match breaks is relatively fast, you can save the times
of writing into the internal flash ROM of an MCU.
z Address-match breaks can be set only in RAM and ROM areas of an MCU.
z Address-match breaks can be set at up to eight points.
z Address-match breaks can be set or canceled even when the user program is being executed.