MC908QT1 FREESCALE [Freescale Semiconductor, Inc], MC908QT1 Datasheet - Page 139

• Manufacturer Part Number: MC908QT1
• Description: Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

15.3.1 Functional Description
Figure 15-9
The monitor module receives and executes commands from a host computer.
and
computer via a standard RS-232 interface.
Freescale Semiconductor
PROGRAMMING
FROM
IS ENABLED)
DEBUGGING
CONDITIONS
AND FLASH
(IF FLASH
Figure 15-12
Table 15-1
shows a simplified diagram of monitor mode entry.
show example circuits used to enter monitor mode and communicate with a host
MONITOR MODE
RESET VECTOR
Figure 15-9. Simplified Monitor Mode Entry Flowchart
PTA0 = 1,
FORCED
BLANK?
YES
MC68HC908QY/QT Family Data Sheet, Rev. 5
YES
NO
NO
MONITOR MODE ENTRY
8 SECURITY BYTES
MONITOR CODE
DOES RESET
HOST SENDS
USER MODE
IS RESET
EXECUTE
POR RESET
IRQ = V
OCCUR?
NORMAL
POR?
NO
TST
?
YES
NO
YES
ENABLE FLASH
MONITOR MODE
PTA1 = 1, AND
PTA4 = 0?
PTA0 = 1,
NORMAL
YES
YES
SECURITY BYTES
CORRECT?
Figure
ARE ALL
NO
15-10,
Monitor Module (MON)
USER MODE
INVALID
DISABLE FLASH
NO
Figure
15-11,
139