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USING THE COM20051'S EMULATION MODE
The
COM20051
is
unique
among
special
purpose 8051 based devices in that it can be
used in conjunction with a standard 16MHz
80C32 ICE. The COM20051 incorporates an
Emulate
mode
that
puts
the
internal
microcontroller
in a high impedance state so
an external processor (like an ICE) can access
the
internal
ARCNET
core
through
the
COM20051's pins. The ICE should be connected
in parallel to the COM20051 as shown in Figure
24. The ICE should operate off of its internal
oscillator.
FIGURE 23 – CONNECTIONS FOR EMULATION MODE
AD0
AD1
AD2
AD3
AD4
AD5
AD6
AD7
A8
A9
A10
A11
A12
A13
A14
P1.0
A15
P1.1
P1.3
P1.4
P1.5
P1.6
P1.0
P1.1
P1.3
P1.4
P1.5
P1.6
P1.7
P1.2
P1.2
P1.7
A10
A15
AD6
AD3
A13
AD4
AD0
C1
C3
C0
AD7
AD1
A14
AD5
C4
A8
A9
AD2
A12
C5
A11
C2
C23
33pf
C22
33pf
8032
31
19
18
9
12
13
14
15
1
2
3
4
5
6
7
8
39
38
37
36
35
34
33
32
21
22
23
24
25
26
27
28
17
16
29
30
11
10
EA/VP
X1
X2
RESET
INT0
INT1
T0
T1
P1.0/T2
P1.1/T2x
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
P0.0
P0.1
P0.2
P0.3
P0.4
P0.5
P0.6
P0.7
P2.0
P2.1
P2.2
P2.3
P2.4
P2.5
P2.6
P2.7
RD
WR
PSEN
ALE/P
TXD
RXD
R19
1.5K
Y1
16Mhz
C2
33pf
C3
33pf
COM20051
35
21
20
10
14
15
16
17
2
3
4
5
6
7
8
9
43
42
41
40
39
38
37
36
24
25
26
27
28
29
30
31
19
18
32
33
13
11
12
23
1
34
EA/VP
X1
X2
RESET
INT0
INT1
T0
T1
P1.0
P1.1
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
P0.0
P0.1
P0.2
P0.3
P0.4
P0.5
P0.6
P0.7
P2.0
P2.1
P2.2
P2.3
P2.4
P2.5
P2.6
P2.7
RD
WR
PSEN
ALE/P
TXD
RXD
PULSE1
PULSE2
RXIN
TXEN
Y3
EMULATOR POD
SMSC COM20051
U1
U3
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