MC68HC08AZ60A Datasheet, PDF (186/480 Pages) Motorola, Inc – Microcontrollers

Monitor ROM (MON)
outlines the available baud rates for a range of crystals and how they can
match to a PC baud rate.
Baud rate
Closest PC baud PC
Error %
Clock freq PTC3=0 PTC3=1 PTC3=0 PTC3=1 PTC3=0 PTC3=1
32kHz
57.97
28.98
57.6
28.8
0.64
0.63
1MHz
1811.59 905.80
1800
900
0.64
0.64
2MHz
3623.19 1811.59 3600
1800
0.64
0.64
4MHz
7246.37 3623.19 7200
3600
0.64
0.64
4.194MHz 7597.83 3798.91 7680
3840
1.08
1.08
4.9152MHz 8904.35 4452.17 8861
4430
0.49
0.50
8MHz 14492.72 7246.37 14400
7200
0.64
0.64
16MHz 28985.51 14492.75 28800 14400
0.64
0.64
Care should be taken when setting the baud rate since incorrect
baud rate setting can result in communications failure.
12.4.6 Security
Security features discourage unauthorized reading of ROM/EEPROM
locations while in monitor mode. The host can bypass the security
features at monitor mode entry by sending eight security bytes that
match the byte locations $FFF6–$FFFD. Locations $FFF6–$FFFD
contain user-defined data.
NOTE: Do not leave locations $FFF6–$FFFD blank. For security reasons, enter
data at locations $FFF6–$FFFD even if they are not used for vectors.
During monitor mode entry, the MCU waits after the power-on reset for
the host to send the eight security bytes on pin PA0.
If the received bytes match those at locations $FFF6–$FFFD, the host
bypasses the security features and can read all ROM/EEPROM
locations and execute code from ROM. Security remains bypassed until
a power-on reset occurs. After the host bypasses security, any reset
other than a power-on reset requires the host to send another eight
Advance Information
186
Monitor ROM (MON)
MC68HC08AZ60A — Rev 0.0
MOTOROLA