MC68HC908RF2 Datasheet, PDF (160/254 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Monitor Read-Only Memory (MON)
Table 10-8. RUN (Run User Program) Command
Description
Executes RTI instruction
Operand
None
Data Returned None
Opcode
$28
Command Sequence
SENT TO
MONITOR
RUN
RUN
1
ECHO
Note 1 = Echo delay (2 bit times)
10.4.6 Baud Rate
With a 9.8304-MHz crystal, data is transferred between the monitor and
host at 9600 baud. If a 14.7456-MHz crystal is used, the monitor baud
rate is 14400.
NOTE: While in monitor mode with V_HI applied to IRQ1, the MCU bus clock is
always driven from the external clock.
10.4.7 Security
A security feature discourages unauthorized reading of FLASH locations
while in monitor mode. The host can bypass the security feature at
monitor mode entry by sending eight consecutive security bytes that
match the bytes at locations $FFF6–$FFFD. Locations $FFF6–$FFFD
contain user-defined data.
NOTE:
Do not leave locations $FFF6–$FFFD blank. For security reasons,
program locations $FFF6–$FFFD even if they are not used for vectors.
If FLASH is unprogrammed, the eight security byte values to be sent are
$00, the unprogrammed state of the FLASH.
During monitor mode entry, the MCU waits after the power-on reset for
the host to send the eight security bytes on pin PA0.
Advance Information
160
Monitor Read-Only Memory (MON)
MC68HC908RF2 — Rev. 1
MOTOROLA