M16C/62 Group DATASHEET

InterruptMitsubishi microcomputersM16C / 62 GroupSINGLE-CHIP 16-BIT CMOS MICROCOMPUTERInterrupts and Interrupt Vector TablesIf an interrupt request is accepted, a program branches to the interrupt routine set in the interrupt vectortable. Set the first address of the interrupt routine in each vector table. Figure 1.14.2 shows the format forspecifying the address.Two types of interrupt vector tables are available — fixed vector table in which addresses are fixed andvariable vector table in which addresses can be varied by the setting.Vector address + 0Vector address + 1Vector address + 2Vector address + 3MSBLow addressMid address0 0 0 0 High address0 0 0 0 0 0 0 0Figure 1.14.2. Format for specifying interrupt vector addressesLSB• Fixed vector tablesThe fixed vector table is a table in which addresses are fixed. The vector tables are located in an areaextending from FFFDC16 to FFFFF16. One vector table comprises four bytes. Set the first address ofinterrupt routine in each vector table. Table 1.14.1 shows the interrupts assigned to the fixed vectortables and addresses of vector tables.Table 1.14.1. Interrupts assigned to the fixed vector tables and addresses of vector tablesInterrupt source Vector table addresses RemarksAddress (L) to address (H)Undefined instruction FFFDC16 to FFFDF16 Interrupt on UND instructionOverflow FFFE016 to FFFE316 Interrupt on INTO instructionBRK instruction FFFE416 to FFFE716 If the vector contains FF16, program execution starts fromthe address shown by the vector in the variable vector tableAddress match FFFE816 to FFFEB16 There is an address-matching interrupt enable bitSingle step (Note) FFFEC16 to FFFEF16 Do not useWatchdog timer FFFF016 to FFFF316________DBC (Note) FFFF416 to FFFF716 Do not useNMIFFFF816 to FFFFB16_______External interrupt by input to NMI pinResetFFFFC16 to FFFFF16Note: Interrupts used for debugging purposes only.53