MC68HC908LJ12 Datasheet, PDF (157/413 Pages) Freescale Semiconductor, Inc – 8-bit microcontroller units

Monitor ROM (MON)
0.1 µF
68HC908LJ12
RST
1
+
10 µF
3
4
10 µF
+2
MC145407
V_TST
(SEE NOTE 3)
10 kΩ
C
(SEE NOTES 2
SW2 ^{AND 3)}
EXTERNAL OSCILLATOR
MUST BE USED FOR
MONITOR MODE ENTRY
WHEN IRQ = V_TST
D
10 kΩ
0.033 µF
20
6–30 pF
C
SW3
(SEE NOTE 2)
+
10 µF
18
32.768 kHz XTAL
D
SW4
C
(SEE NOTE 2)
17
+
10 µF
V_DD
330 kΩ D
6–30 pF
19
RESET VECTORS
$FFFE
$FFFF
IRQ
CGMXFC
OSC1
OSC2
V_SS
V_REFL
DB-25
2
5
3
6
7
V_DD
16
V_DD
15
V_DDA
0.1 µF
V_REFH
V_DD
1
14
MC74HC125
2
3
V_DD
10 kΩ
6
5
4
V_DD
7
V_DD
A
SW1
(SEE NOTE 1)
B
PTA0
PTC1
PTA1
PTA2
Notes:
1. For monitor mode entry when IRQ = V_TST:
SW1: Position A — Bus clock = CGMXCLK ÷ 4 or CGMPCLK ÷ 4
SW1: Position B — Bus clock = CGMXCLK ÷ 2
2. SW2, SW3, and SW4: Position C — Enter monitor mode using external oscillator.
SW2, SW3, and SW4: Position D — Enter monitor mode using external XTAL and internal PLL.
3. See 23.6 5.0V DC Electrical Characteristics for IRQ voltage level requirements.
Figure 10-1. Monitor Mode Circuit
Technical Data
158
Monitor ROM (MON)
MC68HC908LJ12 — Rev. 2.1
Freescale Semiconductor