AN1176 STMicroelectronics, AN1176 Datasheet - Page 6

• Manufacturer Part Number: AN1176
• Description: 68HC11/PSD813F1 DESIGN GUIDE
• Manufacturer: STMicroelectronics

Connections:
M otorola M 68HC11 M CU
and S T Flash PSD813FX
PLCC Package.
Note: O nly the necessary
pins on the 68HC11 are
show n.
2.1 Physical Connections
Connect your 68HC11 to the PSD as shown. The same connections can be used for all five
members of the PSD813F family (PSD813F1 though PSD813F5). Notice that the 16 general
purpose I/O lines that were lost on the 68HC11 for external address and data signals are replaced
by the 16 I/O lines on ports A and B of the PSD. The JTAG programming channel connection is
optional, as well as the battery backup feature for the internal PSD SRAM.
2.2 Memory Map
For this simple design, we’ll use a PSD813F1, which provides 128K bytes flash memory, 32K
bytes EEPROM, and 2K bytes SRAM. We’ll use one half of the EEPROM (16K bytes) to hold
the ISP bootloader code, 68HC11 interrupt vectors, and common firmware functions. We’ll
allocate the remaining 16K bytes of EEPROM for general data storage.
Since the 68HC11 cannot address more than 64K bytes of address space directly, we will use
paging (or banking) to take full advantage of the 162K bytes of total memory on the PSD. The
PSD has a built-in page register for this purpose. Please examine the memory map in Figure 4.
Page
R E S E T \
4
V cc
V cc
Figure 3 – Physical Connections, 68HC11 and PSD813F
M O D A
M O D B
M 68H C 11
R E S E T \
R /W \
A D 0
A D 1
A D 2
A D 3
A D 4
A D 5
A D 6
A D 7
A 1 0
A 1 1
A 1 2
A 1 3
A 1 4
A 1 5
A 8
A 9
D S \
A S
30
31
32
33
34
35
36
37
39
40
41
42
43
44
45
46
47
50
49
10
48
9
8
A D IO 0
A D IO 1
A D IO 2
A D IO 3
A D IO 4
A D IO 5
A D IO 6
A D IO 7
A D IO 8
A D IO 9
A D IO 1 0
A D IO 1 1
A D IO 1 2
A D IO 1 3
A D IO 1 4
A D IO 1 5
C N TL 0
C N TL 1
C N TL 2
P D 0-A S
P D 1-C LK IN
P D 2-C S i\
R E S E T \
P SD 813F
P C 2/V S TB Y
P C 3/TS TA T
P C 4/TE R R
P C 0/TM S
P C 6/TD O
P C 1/TC K
P C 5/TD I
P C 7
P A 0
P A 1
P A 2
P A 3
P A 4
P A 5
P A 6
P A 7
P B 0
P B 1
P B 2
P B 3
P B 4
P B 5
P B 6
P B 7
29
28
27
25
24
23
22
21
52
51
20
19
18
17
14
13
12
11
7
6
5
4
3
2
TM S
TC K
TS TA T
TE R R |
TD I
TD O
O p tion al 3 .6 V
lith ium b attery or cap
JT A G P o rt
O ption al