Freescale Semiconductor, Inc.
Monitor Read-Only Memory (MON)
Functional Description
Table 10-2 is a summary of the differences between user mode and
monitor mode.
Table 10-2. Mode Differences
Functions
Modes
Reset
Vector Vector Vector Vector Vector Vector
High Low High Low High Low
Reset
Break
Break
SWI
SWI
COP
User
Enabled
$FFFE $FFFF $FFFC $FFFD $FFFC $FFFD
$FEFE $FEFF $FEFC $FEFD $FEFC $FEFD
(1)
Monitor
Disabled
1. If the high voltage (VHI) is removed from the IRQ1 pin while in monitor mode, the SIM
asserts its COP enable output. The COP is a mask option enabled or disabled by the
COPD bit in the configuration register. See 17.7 3.0-Volt DC Electrical Characteristics
Excluding UHF Module.
10.4.2 Data Format
Communication with the monitor ROM is in standard non-return-to-zero
(NRZ) mark/space data format. (See Figure 10-2 and Figure 10-3.)
The data transmit and receive rate is determined by the crystal. Transmit
and receive baud rates must be identical.
NEXT
START
BIT
START
BIT
STOP
BIT
BIT 0
BIT 1
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
1, 2, 3
Notes: 1 = Echo delay (2 bit times)
2 = Data return delay (2 bit times)
3 = Wait 1 bit time before sending next byte.
Figure 10-2. Monitor Data Format
MC68HC908RFRK2
MOTOROLA
AdvanceInformation
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Monitor Read-Only Memory (MON)
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