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MC68HC08BD24 Datasheet, PDF (109/244 Pages) Motorola, Inc – HCMOS Microcontroller Unit
Alternatively, the host can send a RUN command, which executes an
RTI, and this can be used to send control to the address on the stack
pointer.
The COP module is disabled in monitor mode as long as VTST is applied
to the IRQ or the RST pin. (See Section 7. System Integration Module
(SIM) for more information on modes of operation.)
Table 9-2 is a summary of the differences between user mode and
monitor mode.
Table 9-2. Mode Differences
Functions
Modes
COP
Reset
Vector
High
Reset
Vector
Low
SWI
Vector
High
SWI
Vector
Low
User
Monitor
Enabled
Disabled(1)
$FFFE
$FEFE
$FFFF
$FEFF
$FFFC
$FEFC
$FFFD
$FEFD
Notes:
1. If the high voltage (VTST) is removed from the IRQ pin, the SIM asserts its COP enable
output. The COP is a mask option enabled or disabled by the COPD bit in the configuration
register.
9.4.2 Data Format
Communication with the monitor ROM is in standard non-return-to-zero
(NRZ) mark/space data format. (See Figure 9-2 and Figure 9-3.)
NEXT
START
START
BIT BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 BIT 7 STOP BIT
BIT
Figure 9-2. Monitor Data Format
NEXT
$A5
START
BIT BIT 0
BIT 1
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
START
BIT 7 STOP BIT
BIT
START
STOP
BREAK BIT BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 BIT 7 BIT
Figure 9-3. Sample Monitor Waveforms
MC68HC08BD24 — Rev. 1.1
Freescale Semiconductor
Technical Data
109