Motorola M68HC11EVBD, User Manual

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MONITOR PROGRAM
M68HC11EVBU/D 3-5 5
3.2.5 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 an example:
FCB 3 3 characters in command name
FCC ’ASM’ ASCII literal command name string
FDB ASM Jump address for command module
Each command in the BUFFALO program is a individual module. Thus, to add or delete
commands, all that is required is to include a new command module or delete an existing module
and/or delete the entry in the command table. This procedure may be difficult to accomplish with
the M68HC11EVBU because the BUFFALO monitor is contained in ROM. However with the
standard M68HC11EVB, you may change commands, as this version of the BUFFALO monitor
is contained in EPROM.
3.3 INTERRUPT VECTORS
Interrupt vectors residing in MCU internal ROM are accessible as follows. Each vector is
assigned a three byte field residing in EVBU memory map locations $0000-$00FF. This is where
the monitor program expects the MCU RAM to reside. Each vector points to a three byte field
which is used as a jump table to the vector service routine. Table 3-2 lists the interrupt vectors
and associated three byte field.
Table 3-2. Interrupt Vector Jump Table
Interrupt Vector Field
Serial Communications Interface (SCI) $E0C4 – $E0C6
Serial Peripheral Interface (SPI) $E0C7 – $E0C9
Pulse Accumulator Input Edge $E0CA – $E0CC
Pulse Accumulator Overflow $E0CD – $E0CF
Timer Overflow $E0D0 – $E0D2
Timer Output Compare 5 $E0D3 – $E0D5
Timer Output Compare 4 $E0D6 – $E0D8
Timer Output Compare 3 $E0D9 – $E0DB
Timer Output Compare 2 $E0DC – $E0DE
Timer Output Compare 1 $E0DF – $E0E1