Datasheet
REV. 0
ADuC816
–66–
comes with the single-pin emulator available from Accutron Limited
(www.accutron.com), use a 2-pin 0.1-inch pitch “Friction Lock”
header from Molex (www.molex.com) such as their part number
22-27-2021. Be sure to observe the polarity of this header. As
represented in Figure 52, when the Friction Lock tab is at the
right, the ground pin should be the lower of the two pins (when
viewed from the top).
Enhanced-Hooks Emulation Mode
ADuC816 also supports enhanced-hooks emulation mode. An
enhanced-hooks-based emulator is available from Metalink Corpo-
ration (www.metaice.com). No special hardware support for these
emulators needs to be designed onto the board since these are
“pod-style” emulators where users must replace the chip on
their board with a header device that the emulator pod plugs
into. The only hardware concern is then one of determining if
adequate space is available for the emulator pod to fit into the
system enclosure.
Typical System Configuration
A typical ADuC816 configuration is shown in Figure 52. It sum-
marizes some of the hardware considerations discussed in the
previous paragraphs.
Figure 52 also includes connections for a typical analog measure-
ment application of the ADuC816, namely an interface to an
RTD (Resistive Temperature Device). The arrangement shown
is commonly referred to as a 4-wire RTD configuration.
Here, the on-chip excitation current sources are enabled to excite
the sensor. An external differential reference voltage is generated
by the current sourced through resistor R1. This current also flows
directly through the RTD, which generates a differential voltage
directly proportional to temperature. This differential voltage is
routed directly to the positive and negative inputs of the primary
ADC (AIN1, AIN2 respectively). A second external resistor, R2, is
used to ensure that absolute analog input voltage on the negative
input to the primary ADC stays within that specified for the
ADuC816, i.e., AGND + 100 mV.
C1+
V+
C1–
C2+
C2–
V–
T2OUT
R2IN
V
CC
GND
T1OUT
R1IN
R1OUT
T1IN
T2IN
R2OUT
ADM202
DV
DD
39
40
47
46
44
43
42
41
52
51
50
49
48
45
DV
DD
1k
DV
DD
1k
2-PIN HEADER FOR
EMULATION ACCESS
(NORMALLY OPEN)
DOWNLOAD/DEBUG
ENABLE JUMPER
(NORMALLY OPEN)
32.766kHz
DV
DD
1
9-PIN D-SUB
FEMALE
2
3
4
5
6
7
8
9
AV
DD
V
REF
+
V
REF
–
A
IN
+
A
IN
–
200A/400A
EXCITATION
CURRENT
R2
510
RTD
R1
5.6k
AV
DD
AGND
P1.2IEXC1/DAC
REFIN–
REFIN+
P1.4/AIN1
P1.5/AIN2
DV
DD
DGND
PSEN
EA
DGND
DV
DD
XTAL2
XTAL1
RESET
RXD
TXD
DV
DD
DGND
ADM810
V
CC
RST
GND
DVDD
NOT CONNECTED IN THIS EXAMPLE
DV
DD
ADuC816
27
34
33
31
30
29
28
38
37
36
35
32
Figure 52. Typical System Configuration
REV. A