32186 datasheet(104/1032 Pages) RENESAS

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EIT

4-2

32185/32186 Group Hardware Manual

Rev.1.10 REJ09B0235-0110 May 15, 07

4.1 Outline of EIT

If some event occurs when the CPU is executing an ordinary program, it may become necessary to suspend

the program being executed and execute another program. Events like this one are referred to by a generic

name as EIT (Exception, Interrupt and Trap).

(1) Exception

This is an event related to the context being executed. It is generated by an error or violation during instruc-

tion execution. This type of event includes Address Exception (AE), Reserved Instruction Exception (RIE)

and Floating-Point Exception (FPE).

(2) Interrupt

This is an event generated irrespective of the context being executed. It is generated by a hardware-derived

signal from an external source, as well as by the internal peripheral I/O. This type of event includes Reset

Interrupt (RI), System Break Interrupt (SBI) and External Interrupt (EI).

(3) Trap

This refers to a software interrupt generated by executing a TRAP instruction. This type of event is intention-

ally generated in a program as in the OS’s system call by the programmer.

4.1 Outline of EIT

EIT

Exception (Exception)

Reserved Instruction Exception (RIE)

Address Exception (AE)

Floating-Point Exception (FPE)

Reset Interrupt (RI)

System Break Interrupt (SBI)

External Interrupt (EI)

Trap (TRAP)

Interrupt (Interrupt)

Trap (Trap)

Figure 4.1.1 Classification of EITs

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