
Development Tools and Support
MOTOROLA
MC68302 USER’S MANUAL
B-5
—DTE/DCE
—- Permanent virtual circuit/virtual call
—- D-BIT support
—- On-line registration support
—- TOA/NPI address mode
—- Fast select facility support
—- Logical channel (and group) numbers
—- Protocol parameters (w, T11, T12, T21, T22, N12, N13)
—- Maximum data packet length (unlimited)
Message-oriented interface
Independent of layer 2 and layer 4 implementation
The EDX module features are as follows:
The EDX event driven executive is an operating system kernel that provides:
—Multitasking with simple task scheduling
—Message passing between tasks
—Memory allocation
EDX was designed to be:
—Fast (written mostly in M68000 Assembler)
—Efficient (uses about 1.5 kbytes of ROM)
EDX was designed for use in communications environments. It provides “soft” real-time
scheduling, not the “hard” real-time scheduling needed in many event control applica-
tions.
The approximate compiled object code sizes are as follows:
—Chip Drivers
24K
—LAPD
24K
—LAPB
20K
—X.25
36K
—EDX
1.5K
A RAM scratchpad area (around 4 kbytes) and buffer space are also required for the mod-
ules (except for EDX). Code sizes may be reduced from the figures above if optional module
features are not compiled.
An additional user-interface module provides a menu-driven user interface to the IMP and
each functional protocol module. This module may be used for chip evaluation or as a tool
for debugging user-developed applications. Menu options will allow a user to examine the
appropriate module's memory structures (or the register set and on-chip dual-port RAM of
the IMP) or to issue specific commands. The commands may result in specific IMP com-
mands or in the execution of protocol-defined primitives in one of the protocol modules.
The chip driver module is available in C source code form. The source code requires no li-
cense.