MC68HC08AZ0 Datasheet, PDF (154/444 Pages) Motorola, Inc – Advance Information

Freescale Semiconductor, Inc.
Monitor ROM (MON)
Echoing
SENT TO
MONITOR
ECHO
The monitor ROM immediately echoes each received byte back to the
PTA0 pin for error checking, as shown in Figure 4.
READ
READ ADDR. HIGH ADDR. HIGH ADDR. LOW ADDR. LOW
DATA
Figure 4. Read transaction
RESULT
Any result of a command appears after the echo of the last byte of the
command.
Break signal
A break signal is a start bit followed by nine low bits. This is shown in
Figure 4. When the monitor receives a break signal, it drives the PTA0
pin high for the duration of two bits before echoing the break signal.
MISSING STOP BIT
TWO-STOP-BIT DELAY BEFORE ZERO ECHO
01234567
01234567
Figure 5. Break transaction
Commands
The monitor ROM uses the following commands:
• READ (read memory)
• WRITE (write memory)
• IREAD (indexed read)
• IWRITE (indexed write)
• READSP (read stack pointer)
• RUN (run user program)
MC68HC08AZ0
152
Monitor ROM (MON)
For More Information On This Product,
Go to: www.freescale.com
6-mon
MOTOROLA