DSPIC33FJ32GP302THSLASHSP datasheet(87/403 Pages) MICROCHIP

87 / 403 page

 2009 Microchip Technology Inc.

Preliminary

DS70292D-page 87

dsPIC33FJ32GP302/304, dsPIC33FJ64GPX02/X04, AND dsPIC33FJ128GPX02/X04

7.0

INTERRUPT CONTROLLER

The dsPIC33FJ32GP302/304, dsPIC33FJ64GPX02/

X04,

and

dsPIC33FJ128GPX02/X04

interrupt

controller reduces the numerous peripheral interrupt

request signals to a single interrupt request signal to

the dsPIC33FJ32GP302/304, dsPIC33FJ64GPX02/

X04, and dsPIC33FJ128GPX02/X04 CPU.

The interrupt controller has the following features:

• Up to eight processor exceptions and software

traps

• Eight user-selectable priority levels

• Interrupt Vector Table (IVT) with up to 118 vectors

• A unique vector for each interrupt or exception

source

• Fixed priority within a specified user priority level

• Alternate Interrupt Vector Table (AIVT) for debug

support

• Fixed interrupt entry and return latencies

7.1

Interrupt Vector Table

The Interrupt Vector Table (IVT), shown in Figure 7-1,

resides in program memory, starting at location

000004h. The IVT contains 126 vectors consisting of

eight nonmaskable trap vectors plus up to 118 sources

of interrupt. In general, each interrupt source has its

own vector. Each interrupt vector contains a 24-bit-

wide address. The value programmed into each

interrupt vector location is the starting address of the

associated Interrupt Service Routine (ISR).

Interrupt vectors are prioritized in terms of their natural

priority. This priority is linked to their position in the

vector table. Lower addresses generally have a higher

natural priority. For example, the interrupt associated

with vector 0 takes priority over interrupts at any other

vector address.

dsPIC33FJ32GP302/304,

dsPIC33FJ64GPX02/X04,

and dsPIC33FJ128GPX02/X04 devices implement up

to 53 unique interrupts and five nonmaskable traps.

These are summarized in Table 7-1.

7.1.1

ALTERNATE INTERRUPT VECTOR

TABLE

The Alternate Interrupt Vector Table (AIVT) is located

after the IVT, as shown in Figure 7-1. Access to the

AIVT

provided

the

ALTIVT

control

bit

(INTCON2<15>). If the ALTIVT bit is set, all interrupt

and exception processes use the alternate vectors

instead of the default vectors. The alternate vectors are

organized in the same manner as the default vectors.

The AIVT supports debugging by providing a means to

switch

between

application

and

support

environment without requiring the interrupt vectors to

be reprogrammed. This feature also enables switching

between

applications

for

evaluation

different

software algorithms at run time. If the AIVT is not

needed, the AIVT should be programmed with the

same addresses used in the IVT.

7.2

Reset Sequence

A device Reset is not a true exception because the

interrupt controller is not involved in the Reset process.

The dsPIC33FJ32GP302/304, dsPIC33FJ64GPX02/

X04, and dsPIC33FJ128GPX02/X04 device clears its

registers in response to a Reset, which forces the PC

to zero. The digital signal controller then begins

program execution at location 0x000000. A GOTO

instruction at the Reset address can redirect program

execution to the appropriate start-up routine.

Note 1: This data sheet summarizes the features

the

dsPIC33FJ32GP302/304,

dsPIC33FJ64GPX02/X04,

and

dsPIC33FJ128GPX02/X04

families

devices. It is not intended to be a compre-

hensive reference source. To comple-

ment the information in this data sheet,

refer to “Section 32. Interrupts (Part

III)” (DS70214) of the “dsPIC33F/PIC24H

Family Reference Manual”, which is avail-

able

from

the

Microchip

website

(www.microchip.com).

2: Some registers

and

associated bits

described in this section may not be avail-

able on all devices. Refer to Section 4.0

“Memory Organization” in this data

sheet for device-specific register and bit

information.

Note:

Any unimplemented or unused vector

locations in the IVT and AIVT should be

programmed with the address of a default

interrupt handler routine that contains a

RESET

instruction.

DSPIC33FJ32GP302TH/SP Datasheet(PDF) 87 Page - Microchip Technology

DSPIC33FJ32GP302TH/SP Datasheet(HTML) 87 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL