4-12
Using the 162Bug Debugger
4
162Bug Vector Table and Workspace
As described in the Memory Requirements section of Chapter 3, the
162Bug firmware needs 64KB of read/write memory to operate.
With the exception of the first 1024-byte vector table area, you must
be extremely careful not to use the above-mentioned memory areas
for other purposes.
Refer to the Memory Requirements section of Chapter 3 to determine
how to dictate the location of the reserved memory areas.
Examples
❏If, for example, your program inadvertently wrote over the
static variable area containing the serial communication
parameters, these parameters would be lost, resulting in a
loss of communication with the system console terminal.
❏If your program corrupts the system stack, then an incorrect
value may be loaded into the processor Program Counter
(PC), causing a system crash.
162Bug
reserves ...
For ...
1024-byte area A user program vector table area
1024-byte area An exception vector table for the debugger itself to use
Space for static variables, and initializes these static variables to
predeÞned default values.
Space for the system stack, and initializes the system stack pointer to
the top of this area.