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MC908JB12DWE Datasheet, PDF (125/332 Pages) Freescale Semiconductor, Inc – MC68HC908JB16 Technical Data | |||
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Monitor ROM (MON)
VDD
VTST
10k â¦
10k â¦
(SEE NOTE 2)
C
SW2
0.1 µF
D
1
+
10 µF
3
4
10 µF
+2
DB-25
2
5
3
6
7
MC145407
VDD
12 MHz
+
4.7 µF
0.1 µF
VDD
(SEE NOTE 3)
0.1 µF
20
+
10 µF
18
12 MHz
20 pF
E SW3
F
E
fXCLK
17
10 µF VDD
19 +
16
15
F
20 pF
VDD
10 kâ¦
A
(SEE NOTE 1) B
SW1
VDD
1
14
MC74HC125
2
3
6
5
4
VDD
10 kâ¦
VDD
10 kâ¦
7
VDD
NOTES:
1. Affects high voltage entry to monitor mode only (SW2 at position C):
SW1: Position A â Bus clock = fXCLK ÷ 2
SW1: Position B â Bus clock = fXCLK
2. SW2: Position C â High-voltage entry to monitor mode.
SW2: Position D â Low-voltage entry to monitor mode (with blank reset vector).
See Section 20. for IRQ voltage level requirements.
3. SW3: Position E â OSC1 directly driven by external oscillator.
SW3: Position F â OSC1 driven by crystal oscillator circuit.
10 kâ¦
10 kâ¦
RST
HC908JB16
IRQ
VREG
VDD
VSS
OSC1
OSC2
PTA3
PTA0
PTA1
PTE3
PTA2
Figure 9-1. Monitor Mode Circuit
MC68HC908JB16 â Rev. 1.1
Freescale Semiconductor
Monitor ROM (MON)
Technical Data
125
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