Microcontrollers Data Sheet

MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
258 Freescale Semiconductor Development Support
Table 18-2. Monitor Mode Signal Requirements and Options
IRQ
RESET
(S1)
$FFFE
/$FFFF
PLL PTC3 PTC4
PTC2
(S2)
External
Clock
(1)
1. External clock is derived by a 32.768 kHz crystal or a 4.9152/9.8304 MHz off-chip oscillator.
CGMOUT
Bus
Frequency
COP
For Serial
Communication
(2)
2. DNA = does not apply, X = don’t care
Comment
PTA0
PTA7
(S3)
Baud
Rate
(3) (4)
3. PAT0 = 1 if serial communication; PTA0 = X if parallel communication
4. PTA7 = 0 → serial, PTA7 = 1 → parallel communication for security code entry
X GND X X X X X X 0 0 Disabled X X 0 No operation until reset goes high
V
TST
V
DD
or
V
TST
X OFF100
4.9152
MHz
4.9152
MHz
2.4576
MHz
Disabled
1 0 9600
PTC3 and PTC2 voltages only required if
IRQ
= V
TST
; PTC2 determines frequency
divider
X 1 DNA
V
TST
V
DD
or
V
TST
X OFF101
9.8304
MHz
4.9152
MHz
2.4576
MHz
Disabled
1 0 9600
PTC3 and PTC2 voltages only required if
IRQ
= V
TST
; PTC2 determines frequency
divider
X 1 DNA
V
DD
V
DD
$FFFF
Blank
OFF X X X
9.8304
MHz
4.9152
MHz
2.4576
MHz
Disabled
1 0 9600
External frequency always divided by 4
X 1 DNA
V
DD
or
GND
V
TST
$FFFF
Blank
OFFXXX X — — EnabledXX —
Enters user mode — will encounter an
illegal address reset
V
DD
or
GND
V
DD
or
V
TST
Non-$FF
Programmed
OFF X X X X — — Enabled X X — Enters user mode