mc68hc908mr8 Freescale Semiconductor, Inc, mc68hc908mr8 Datasheet - Page 190

• Manufacturer Part Number: mc68hc908mr8
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Monitor ROM (MON)
10.4.2 Forced Monitor Mode
Technical Data
190
Enter monitor mode by applying a logic 0 and then a logic 1 to the RST
pin (see
Once out of reset, the MCU waits for the host to send eight security
bytes. After receiving the security bytes, the MCU sends a break signal
(10 consecutive logic 0s) to the host computer, indicating that it is ready
to receive a command.
Monitor mode uses alternate vectors for reset and SWI. The alternate
vectors are in the $FE page instead of the $FF page and allow code
execution from the internal monitor firmware instead of user code. The
computer operating properly (COP) module is disabled in monitor mode
as long as V
Section 7. System Integration Module (SIM)
modes of operation.
On FLASH parts, if the voltage applied to the IRQ1 is less than V
MCU will come out of reset in user mode. The memory reset module
monitors the reset vector fetches and will assert an internal reset if it
detects that the reset vectors are erased. When the MCU comes out of
reset with its reset vector erased, it is forced into monitor mode without
requiring high voltage on the IRQ1 pin.
The computer operating properly (COP) module is disabled in forced
monitor mode. Any reset other than a power-on reset (POR) will
automatically force the MCU to come back to the forced monitor mode.
Table 10-2
monitor mode.
Monitor
Modes
1. If the high voltage (V
User
asserts its COP enable output.
Table
Disabled
Enabled
is a summary of the differences between user mode and
HI
COP
is applied to either the IRQ pin or the RST pin. Refer to
Monitor ROM (MON)
10-1)
(1)
HI
Table 10-2. Mode Differences
) is removed from the IRQ pin or the RST pin, the SIM
Vector High
$FFFE
$FEFE
Reset
Vector Low
Functions
$FEFF
$FFFF
Reset
for more information on
MC68HC908MR8 — Rev 4.1
Vector High
$FEFC
$FFFC
Freescale Semiconductor
SWI
Vector Low
$FEFD
$FFFD
SWI
HI
, the