ADUC843 Analog Devices, ADUC843 Datasheet - Page 76

• Manufacturer Part Number: ADUC843
• Description: Precision Analog Microcontroller: 16MIPS 8052 Flash MCU + 8-Ch 12-Bit ADC
• Manufacturer: Analog Devices

Specifications of ADUC843

• Mcu Core: 8052
• Mcu Speed (mips): 16
• Sram (bytes): 2304Bytes
• Gpio Pins: 34
• Adc # Channels: 8
• Other: PWM

ADuC841/ADuC842/ADuC843
OTHER HARDWARE CONSIDERATIONS
To facilitate in-circuit programming, plus in-circuit debug and
emulation options, users will want to implement some simple
connection points in their hardware to allow easy access to
download, debug, and emulation modes.
In-Circuit Serial Download Access
Nearly all ADuC841/ADuC842/ADuC843 designs want to take
advantage of the in-circuit reprogrammability of the chip. This
is accomplished by a connection to the ADuC841/ADuC842/
ADuC843’s UART, which requires an external RS-232 chip for
level translation if downloading code from a PC. Basic configura-
tion of an RS-232 connection is illustrated in Figure 85 with a
simple ADM202 based circuit. If users would rather not design
an RS-232 chip onto a board, refer to Application Note uC006, A
4-Wire UART-to-PC Interface, (at www.analog.com/microconverter)
VREF OUTPUT
DAC OUTPUT
ANALOG INPUT
C1+
V+
C1–
C2+
C2–
V–
T2OUT
R2IN
AV
ADM202
Figure 85. Example System (PQFP Package), DACs Not Present on ADuC843
DD
R1OUT
R2OUT
T1OUT
GND
R1IN
T1IN
T2IN
V
CC
ADC0
AV
AGND
C
V
DAC0
DAC1
52
REF
REF
DD
DV
51
DD
ADuC841/ADuC842/ADuC843
50
49
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DV
48
DD
DV
47
DD
46
9-PIN D-SUB
FEMALE
45
DOWNLOAD/DEBUG
(NORMALLY OPEN)
1
2
3
4
5
6
7
8
9
ENABLE JUMPER
44
for a simple (and zero-cost-per-board) method of gaining in-
circuit serial download access to the part.
In addition to the basic UART connections, users also need a
way to trigger the chip into download mode. This is accom-
plished via a 1 k
the PSEN pin, as shown in Figure 85. To get the part into download
mode, simply connect this jumper and power-cycle the device
(or manually reset the device, if a manual reset button is available),
and it will be ready to serially receive a new program. With the
jumper removed, the device comes up in normal mode (and
runs the program) whenever power is cycled or RESET is toggled.
1kΩ
43
42
NOT CONNECTED IN THIS EXAMPLE
41
XTAL2
XTAL1
DGND
DV
40
DD
1kΩ
DV
39
38
37
36
35
34
33
32
31
30
29
28
27
DD
Ω
pull-down resistor that can be jumpered onto
DV
DD
2-PIN HEADER FOR
EMULATION ACCESS
(NORMALLY OPEN)
11.0592MHz (ADuC841)
32.768kHz (ADuC842/ADuC843)