AMX 68000, Target Guide

A-6

DAK

AMX 68000 Target Guide

Conforming ISP Declarations

The Target Parameter File must include a definition of an ISP root for each conforming

Interrupt Service Procedure (ISP) which you intend to use in your application. The ISP

root definition is provided using one of the following directives. The ISP root is declared

using ...ISPC if its Interrupt Handler is coded in C or ...ISPA if its Interrupt Handler is

coded in assembly language.

...ISPC ISPROOT,HANDLER,VNUM,PARAM,PARTYPE

...ISPA ISPROOT,HANDLER,VNUM,PARAM,PARTYPE

ISPROOT Name of the ISP root entry point

HANDLER Name of the public device Interrupt Handler

VNUM Interrupt vector number assigned to the device

PARAM Interrupt Handler parameter

PARTYPE Parameter PARAM type

If your Interrupt Handler does not require a parameter, leave field PARAM blank (empty)

and set PARTYPE to 0.

If your Interrupt Handler requires a numeric parameter, set PARAM to the 32-bit signed or

unsigned value and set PARTYPE to 0. The numeric value must be expressed in a form

acceptable to your assembler.

If your Interrupt Handler requires a pointer to a public variable as a parameter, let PARAM

be the name of that variable and set PARTYPE to 1.

VNUM defines the interrupt vector number which you have assigned to the device. VNUM is

25 to 31 or 64 to 255. Note that all other vector numbers in the range 0 to 255 are

reserved by Motorola.

If VNUM is 0 to 255, AMX will automatically install the pointer to the ISP root ISPROOT

into vector number VNUM in the AMX Vector Table when AMX is launched. The pointer

will be installed by AMX before any application Restart Procedures execute.

Consequently, you must ensure that interrupts from the device are not possible at the time

AMX is launched.

If VNUM is -1, you must provide a Restart Procedure or task which installs the pointer to

the ISP root ISPROOT into the AMX Vector Table using AMX procedure cjksivtwr or

cjksivtx.

Note

Parameter VNUM cannot be adjusted using the AMX

Configuration Builder. This parameter is provided for

compatibility with other AMX implementations.