MC68HC908MR8 Datasheet, PDF (192/372 Pages) Motorola, Inc – Microcontrollers

Monitor ROM (MON)
10.4.5 Echoing
As shown in Figure 10-4, the monitor ROM immediately echoes each
received byte back to the PTB1/TXD pin for error checking.
SENT TO
MONITOR
ECHO
READ
READ ADDR. HIGH ADDR. HIGH ADDR. LOW ADDR. LOW DATA
Figure 10-4. Read Transaction
RESULT
Any result of a command appears after the echo of the last byte of the
command.
10.4.6 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 delays two bit times before
echoing the break signal.
MISSING STOP BIT
TWO-STOP-BIT DELAY BEFORE ZERO ECHO
01234567
01234567
Figure 10-5. Break Transaction
Technical Data
192
Monitor ROM (MON)
MC68HC908MR8 — Rev 4.1
Freescale Semiconductor