M16C26 Datasheet, PDF (53/239 Pages) Renesas Technology Corp – 16-BIT CMOS SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/20 SERIES

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Preliminary Specifications Rev. 0.9
Specifications in this manual are tentative and subject to change.
Interrupts
M16C/26 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Interrupts and Interrupt Vector Tables
If an interrupt request is accepted, a program branches to the interrupt routine set in the interrupt vector
table. The first address of the interrupt routine is stored in the corresponding vector. Figure 1.9.2 shows
the format for specifying the address.
Two types of interrupt vector tables are available — fixed vector table in which addresses are fixed and
variable vector table in which addresses can be varied by the setting.
MSB
LSB
Vector address + 0
Vector address + 1
Vector address + 2
Vector address + 3
Figure 1.9.2. Format for specifying interrupt vector addresses
• Fixed vector table
The fixed vector table is a table in which addresses are fixed. The vector tables are located in an
address range extending from FFFDC16 to FFFFF16. A vector consists of four bytes. Set the first
address of interrupt routine in the corresponding vector. Table 1.9.1 shows the interrupts assigned to
the fixed vector table and the vector addresses.
Table 1.9.1. Interrupts assigned to the fixed vector tables and addresses of vector tables
Interrupt source
Vector table addresses
Address (L) to address (H)
Remarks
Undefined instruction
Overflow
BRK instruction
FFFDC16 to FFFDF16
FFFE016 to FFFE316
FFFE416 to FFFE716
Address match
Single step (Note)
Watchdog timer,
Oscillation stop and
re-oscillation detection,
VDET4 detection
DBC (Note)
NMI
Reset
FFFE816 to FFFEB16
FFFEC16 to FFFEF16
FFFF016 to FFFF316
FFFF416 to FFFF716
FFFF816 to FFFFB16
FFFFC16 to FFFFF16
Interrupt on UND instruction
Interrupt on INTO instruction
If the vector contains FF16, program execution starts from
the address shown by the vector in the variable vector table.
There is an address-matching interrupt enable bit.
Do not use.
Do not use.
External interrupt by input to NMI pin.
Note: Interrupts used for debugging purposes only.
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