Limitations On Peripheral Functions; Limitations On Flag Register; Operation On Peripheral I/O During A Break; Interrupts Used By Uart Debugger - Renesas M16C R8C UART Debugger User Manual

5.10. Limitations on Peripheral Functions

UART0 is used for communication between the monitor program and the host computer. Do
not use UART0 in the user program. Do not connect the pins below to other pins as they are
used for communication with the host computer.
• R8C/M11A Group
P1_6/TRCIOB (9pin), P1_4/TRJO/TRCIOB (11pin)
• R8C/M12A Group
T P1_6/TRCIOB (14pin), P1_4/TRJO/TRCIOB (16pin)

5.11. Limitations on Flag Register

When using the user program to rewrite the flag register, execute the FSET and
FCLR instructions to prevent the debug flag (D flag) from being rewritten.

5.12. Operation on Peripheral I/O During a Break

Although an interrupt cannot be accepted during a break, peripheral I/O continues operating.
For example, when stopping a user program by a break during timer operation, the timer
continues counting, but the timer interrupt cannot be accepted.

5.13. Interrupts used by UART Debugger

The BRK instruction interrupt, address match interrupt, single-step interrupt and address
break interrupt are used by UART Debugger. Therefore, make sure the user program does
not use any of these interrupts.
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