AN2408 Freescale Semiconductor / Motorola, AN2408 Datasheet - Page 18

• Manufacturer Part Number: AN2408
• Description: Examples of HCS12 External Bus Design A Companion Note to AN2287/D
• Manufacturer: Freescale Semiconductor / Motorola

Example #7 — Word-Wide External Device Interface – 100BASE-T Ethernet
Software
Application note AN2287 details the signals necessary to implement the external interfaces that the first
part of this note uses for example interfaces. This section will detail the four MCU registers that control
these interfaces. AN2287 suggests booting the device in normal single-chip mode and then adjusting
these registers with software for the proper operating mode. Refer to the device user guide concerning
the writeability of all the registers. On most devices, these registers can only be written to once and only
under special circumstances.
18
PAD[0..15]
These buffers will create desired delay
for address bus
VCC_5V
74ABT16373B DGG
VCC_5V
PAD15
PAD14
PAD13
PAD12
PAD11
PAD10
PAD9
PAD8
PAD7
PAD6
PAD5
PAD4
PAD3
PAD2
PAD1
PAD0
GND
Figure 18. Word-Wide External Device Interface — 100BASE-T Ethernet
C18
0.1uF
24
25
48
26
27
29
30
32
33
35
36
37
38
40
41
43
44
46
47
1
U29
2OE
1OE
2LE
1LE
2D8
2D7
2D6
2D5
2D4
2D3
2D2
2D1
1D8
1D7
1D6
1D5
1D4
1D3
1D2
1D1
C19
0.1uF
GND
RWn
ECLK
C20
0.1uF
2Q8
2Q7
2Q6
2Q5
2Q4
2Q3
2Q2
2Q1
1Q8
1Q7
1Q6
1Q5
1Q4
1Q3
1Q2
1Q1
VCC_5V
23
22
20
19
17
16
14
13
12
11
9
8
6
5
3
2
1
2
C21
0.1uF
GND
U31A
MC74HC00AD
Examples of HCS12 External Bus Design, Rev. 2
EAD15
EAD14
EAD13
EAD12
EAD11
EAD10
EAD9
EAD8
EAD7
EAD6
EAD5
EAD4
EAD3
EAD2
EAD1
EAD0
C14
0.1uF
RESETn
PAD[0..15]
3
Voltage level
shifting
PAD0
PAD1
PAD2
PAD3
PAD4
PAD5
PAD6
PAD7
PAD8
PAD9
PAD10
PAD11
PAD12
PAD13
PAD14
PAD15
GND
VCC_5V
10
12
13
4
5
9
EAD[0..15]
U31B
MC74HC00AD
U31C
MC74HC00AD
U31D
MC74HC00AD
VCC_5V
GND
11
12
13
14
16
17
19
20
22
23
2
3
5
6
8
9
0.1uF
C11
1B1
1B2
1B3
1B4
1B5
1B6
1B7
1B8
2B1
2B2
2B3
2B4
2B5
2B6
2B7
2B8
6
8
11
0.1uF
C12
MEMWn
MEMRn
RESET
0.1uF
1DIR
2DIR
C13
1OE
2OE
1A1
1A2
1A3
1A4
1A5
1A6
1A7
1A8
2A1
2A2
2A3
2A4
2A5
2A6
2A7
2A8
U30
74ABT16245B DGG
GND
47
46
44
43
41
40
38
37
36
35
33
32
30
29
27
26
1
24
48
25
0.1uF
C14
XPAD0
XPAD1
XPAD2
XPAD3
XPAD4
XPAD5
XPAD6
XPAD7
XPAD8
XPAD9
XPAD10
XPAD11
XPAD12
XPAD13
XPAD14
XPAD15
RWn
GND
VCC3.3V
XPAD[0..15]
LSTRBn
EAD0
EAD1
GND
EAD2
EAD3
EAD4
EAD5
EAD6
EAD7
EAD8
EAD9
EAD10
EAD11
EAD12
EAD13
EAD14
EAD15
XPAD0
XPAD1
XPAD2
XPAD3
XPAD4
XPAD5
XPAD6
XPAD7
XPAD8
XPAD9
XPAD10
XPAD11
XPAD12
XPAD13
XPAD14
XPAD15
RESET
ECLK
INTRQ0
MEMRn
MEMWn
VCC3.3V
107
106
105
104
102
101
100
97
96
95
94
41
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
99
76
75
74
73
71
70
69
68
66
65
64
63
61
60
59
58
56
55
54
53
51
50
49
48
30
37
42
38
46
43
29
45
31
32
34
35
36
40
U28
nBE3
nBE2
nBE1
nBE0
AEN
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10
A11
A12
A13
A14
A15
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10
D11
D12
D13
D14
D15
D16
D17
D18
D19
D20
D21
D22
D23
D24
D25
D26
D27
D28
D29
D30
D31
RESET
ADSn
LCLK
ARDY
nRDY RTN
nSRDY
INTR0
nLDEV
RDn
WRn
DATACSn
CY CLEn
W/Rn
VLBUSn
Freescale Semiconductor
LAN91C111-NE
GND
TXEN100
CSOUTn
CNTRLn
CRS100
COL100
X25OUT
ENEEP
RBIAS
RXDV
RXER
MCLK
EEDO
EECS
XTAL2
XTAL1
LEDA
LEDB
RXD3
RXD2
RXD1
RXD0
EESK
TPO+
LNKn
TXD3
TXD2
TXD1
TXD0
RX25
EEDI
TPO-
MDO
TX25
IOS0
IOS1
IOS2
TPI+
TPI-
LBK
MDI
14
15
17
18
20
21
28
12
22
23
121
122
123
124
113
114
115
116
111
119
112
125
126
25
26
27
118
109
3
4
5
6
7
8
9
10
128
127
2
47