AN2408 Freescale Semiconductor / Motorola, AN2408 Datasheet - Page 11

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

Freescale Semiconductor
PTK6/7
PTK0
PTK1
PTK2
PTK3
PTK4
PTK5
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
PE4
PE2
Memory Map
00
10
MCU_XADDR[14]
MCU_XADDR[15]
MCU_XADDR[16]
MCU_XADDR[17]
MCU_XADDR[18]
MCU_XADDR[19]
MCU ADDR[0]
MCU ADDR[1]
MCU ADDR[2]
MCU ADDR[3]
MCU ADDR[4]
MCU ADDR[5]
MCU ADDR[6]
MCU ADDR[7]
MCU ADDR[8]
MCU ADDR[9]
MCU ADDR[10]
MCU ADDR[11]
MCU ADDR[12]
MCU ADDR[13]
MCU ADDR[14]
MCU ADDR[15]
MCU XCS
MCU ECLK
MCU R/W
01
11
02
12
Figure 9. Byte-Wide SRAM Interface (Narrow Mode) XCS/ECS Gated
03
13
04
14
05
15
06
16
External RAM
07
17
13
14
17
18
11
47
46
44
43
41
40
38
37
36
35
33
32
30
29
27
26
48
25
24
08
18
3
4
7
8
1
1
Examples of HCS12 External Bus Design, Rev. 2
U14
74FCT373/SO
U15
74FCT16373/SO
09
19
D0
D1
D2
D3
D4
D5
D6
D7
LE
OE
1D1
1D2
1D3
1D4
1D5
1D6
1D7
1D8
2D1
2D2
2D3
2D4
2D5
2D6
2D7
2D8
1LE
2LE
1OE
2OE
Figure 10. Memory Map of
0A
1A
1Q1
1Q2
1Q3
1Q4
1Q5
1Q6
1Q7
1Q8
2Q1
2Q2
2Q3
2Q4
2Q5
2Q6
2Q7
2Q8
0B
1B
Q0
Q1
Q2
Q3
Q4
Q5
Q6
Q7
0C
1C
Example #4 — Byte-Wide SRAM Interface (Narrow Mode) XCS/ECS Gated
2
5
6
9
12
15
16
19
2
3
5
6
8
9
11
12
13
14
16
17
19
20
22
23
0D
1D
ADDR[0]
ADDR[1]
ADDR[2]
ADDR[3]
ADDR[4]
ADDR[5]
ADDR[6]
ADDR[7]
ADDR[8]
ADDR[9]
ADDR[10]
ADDR[11]
ADDR[12]
ADDR[13]
ADDR[14]
ADDR[15]
0E
1E
XADDR[14]
XADDR[15]
XADDR[16]
XADDR[17]
XADDR[18]
XADDR[19]
0F
1F
0000
FFFF
3E
30
3F
31
2
3
1
U17A
74FCT139A/SO
32
A
B
G
33
34
Y0
Y1
Y2
Y3
Figure 9
35
4
5
6
7
36
XADDR19
37
Internal Flash
1
0
0
0
0
38
14
15
16
17
18
20
21
22
23
24
32
33
34
35
31
13
39
R/W
1
2
3
4
5
6
X
0
0
1
1
U16
AS7C4096/SO
3A
ECLK
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10
A11
A12
A13
A14
A15
A16
A17
A18
OE
WE
CE
X
0
1
0
1
3B
OE
3C
1
1
1
1
0
I/O1
I/O2
I/O3
I/O4
I/O5
I/O6
I/O7
I/O8
WE
3D
1
1
0
1
1
3E
7
8
11
12
25
26
29
30
A to B
A to B
A to B
A to B
B to A
DIR
3F
DATA[8]
DATA[9]
DATA[10]
DATA[11]
DATA[12]
DATA[13]
DATA[14]
DATA[15]
PPAGE
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
11