User manual

Monitor12 (MON12) User Manual 05/30/01

COMMAND TABLE

The command table consists of three lines for each entry. The first byte is the

number of characters in the command name. The second entry is the ASCII command

name. The third entry is the starting address of the command module. As and

example:

FCB 2 2 characters in command name

FCC 'MM' ASCII literal command name string

FDB #MEMORY Jump address for command module

Each command in the Monitor program is a individual module. Thus, to add or

delete commands, all that is required is to include a new command table.

INTERRUPT VECTORS

Interrupt vectors reside in Monitor Program memory and are accessible as pseudo

vectors in a ram based look-up table. Each vector is assigned a two byte field

residing in HC12 internal Ram. The Ram table may be relocated for different

types of HC12 devices so that it remains in internal ram. Each pseudo vector

operates similar to the firmware interrupt vectors, the pseudo vector contents

are the memory address of the interrupt service routine. An interrupt service

can be located anywhere in the 64K byte address map by the user except at

address $0000. If an interrupt occurs for an empty vector, it will be trapped by

the monitor. The monitor trap service will provide the vector offset number for

the trapped interrupt. This number represents the pseudo vector location in the

Ram table. To recover from a trapped interrupt, the EVB board must be Reset.

The following Table lists the pseudo and associated hardware interrupt vectors:

Ram Table base address for the HC12D60 = $600.