MC68HC708MP16 Datasheet, PDF (196/398 Pages) Freescale Semiconductor, Inc – Microcontrollers

Monitor ROM (MON)
10.4.3 Echoing
As shown in Figure 10-4, the monitor ROM immediately echoes each
received byte back to the PTA0 pin for error checking.
SENT TO
MONITOR
READ
READ ADDR. HIGH ADDR. HIGH ADDR. LOW ADDR. LOW DATA
ECHO
RESULT
Figure 10-4. Read Transaction
Any result of a command appears after the echo of the last byte of the
command.
10.4.4 Break Signal
A start bit followed by nine low bits is a break signal. (See Figure 10-5.)
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 10-5. Break Transaction
Technical Data
196
Monitor ROM (MON)
MC68HC708MP16 — Rev. 3.1
Freescale Semiconductor