MC68HC908MR16/MC68HC908MR32 — Rev. 4.0 Advance Information
MOTOROLA Monitor ROM (MON) 185
Advance Information — MC68HC908MR16/MC68HC908MR32
Section 10. Monitor ROM (MON)

10.1 Contents

10.2 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .185
10.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .186
10.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .186
10.4.1 Entering Monitor Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . .188
10.4.1.1 Normal Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . .188
10.4.1.2 Forced Monitor Mode. . . . . . . . . . . . . . . . . . . . . . . . . . .190
10.4.2 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .191
10.4.3 Echoing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .191
10.4.4 Break Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .192
10.4.5 Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .192
10.4.6 Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .196
10.5 Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .196

10.2 Introduction

This section describes the monitor read-only memory (ROM ). The
monitor ROM (MON) allows complete testing of the microcontroller unit
(MCU) through a single-wire interface with a host computer.
Monitor mode entry can be achieved without the use of VTST as long as
vector addresses $FFFE and $FFFF are blank, thus reducing the
hardware requirements for in-circuit programming.