ADUC816 Analog Devices, ADUC816 Datasheet - Page 66

• Manufacturer Part Number: ADUC816
• Description: Precision Analog Microcontroller: 1MIPS 8052 MCU + 8kB Flash + Dual 16-Bit ADC + 12-Bit DAC
• Manufacturer: Analog Devices

Specifications of ADUC816

• Mcu Core: 8052
• Mcu Speed (mips): 1.3
• Sram (bytes): 256Bytes
• Gpio Pins: 34
• Adc # Channels: 4

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.
DVDD
RTD
5.6k
510
R1
R2
V
CC
200 A/400 A
EXCITATION
CURRENT
ADM810
GND
V
V
A
A
REF
REF
IN
IN
AV
C1+
V+
C1–
C2+
C2–
V–
T2OUT
R2IN
+
–
RST
DD
+
–
ADM202
R1OUT
R2OUT
T1OUT
GND
R1IN
T1IN
T2IN
V
CC
P1.2IEXC1/DAC
AV
AGND
REFIN–
REFIN+
P1.4/AIN1
P1.5/AIN2
52
DD
DV
51
DD
50
49
DV
48
ADuC816
DD
DV
47
DD
46
9-PIN D-SUB
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.
FEMALE
45
DOWNLOAD/DEBUG
(NORMALLY OPEN)
1
3
4
6
7
8
2
5
9
ENABLE JUMPER
44
1k
43
42
NOT CONNECTED IN THIS EXAMPLE
41
XTAL2
XTAL1
DGND
DV
40
1k
DD
DV
39
38
37
36
35
34
33
32
30
29
28
27
31
DD
32.766kHz
DV
DD
2-PIN HEADER FOR
EMULATION ACCESS
(NORMALLY OPEN)
REV. A