Undefined Instruction Exception; Privileged Instruction Exception; Floating-Point Exception; Reset - Renesas RX100 Series User Manual

RX13T Group
13.1.1

Undefined Instruction Exception

An undefined instruction exception occurs when execution of an undefined instruction (an instruction not implemented)
is detected.
13.1.2

Privileged Instruction Exception

A privileged instruction exception occurs when execution of a privileged instruction is detected in user mode. Privileged
instructions can be executed only in supervisor mode.
13.1.3

Floating-Point Exception

Floating-point exceptions include the five exception events (overflow, underflow, inexact, division-by-zero, and invalid
operation) specified in the IEEE754 standard and another floating-point exception that is generated on detection of
unimplemented processing. The exception handling of floating-point exceptions is prohibited when the EX, EU, EZ, EO,
or EV bit in FPSW is 0.
13.1.4

Reset

A reset is generated by input of a reset signal to the CPU. This has the highest priority of any exception and is always
accepted.
13.1.5

Non-Maskable Interrupt

A non-maskable interrupt is generated by input of a non-maskable interrupt signal to the CPU and is only used when a
fatal fault is considered to have occurred in the system. Never use the non-maskable interrupt with an attempt to return to
the program that was being executed at the time of interrupt generation after the exception handling routine is ended.
13.1.6

Interrupts

Interrupts are generated by the input of interrupt signals to the CPU. A fast interrupt can be selected as the interrupt with
the highest priority. In the case of the fast interrupt, hardware pre-processing and hardware post-processing are handled
fast. The priority level of the fast interrupt is 15 (the highest). The exception handling of interrupts is masked when the I
bit in PSW is 0.
13.1.7

Unconditional Trap

An unconditional trap is generated when the INT or BRK instruction is executed.
R01UH0822EJ0100 Rev.1.00
Jul 31, 2019
13. Exception Handling
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