MC908AB32CFUE Datasheet, PDF (161/392 Pages) Freescale Semiconductor, Inc – Microcontrollers

Monitor ROM (MON)
Table 10-2 is a summary of the differences between user mode and
monitor mode.
Table 10-2. Mode Differences
Functions
Modes
COP
Reset Reset Break Break SWI
SWI
Vector Vector Vector Vector Vector Vector
High Low High Low High Low
User
Enabled $FFFE $FFFF $FFFC $FFFD $FFFC $FFFD
Monitor _Disabled⁽¹⁾ $FEFE $FEFF $FEFC $FEFD $FEFC $FEFD
Notes:
1. If the high voltage (V_TST) is removed from the IRQ pin while in monitor mode, the SIM
asserts its COP enable output. The COP can be enabled or disabled by the COPD bit in
the configuration register 1 (CONFIG1). (See 23.6 5.0-V DC Electrical Characteristics.)
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 can be anywhere from 4800 baud to
28.8 k-baud. Transmit and receive baud rates must be identical.
NEXT
START
START
BIT BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 BIT 7 ^STOP BIT
BIT
Figure 10-2. 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 10-3. Sample Monitor Waveforms
MC68HC908AB32 — Rev. 1.1
Freescale Semiconductor
Monitor ROM (MON)
Technical Data
161