Datasheet
ADuC814
Rev. A | Page 63 of 72
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ADuC814
ADM202
DGND
DLOAD
RXD
TXD
RESET
ADC0
10nF
AV
DD
AV
DD
DV
DD
AGND
DAC1
OUTPUT
DAC0
OUTPUT
0.1
µ
F
0.1
µ
F
32.766kHz
0.1
µ
F
R2IN
T2OUT
V–
C2–
C2+
C1–
V1+
C1+
1
2
3
4
5
6
7
8
9
DV
DD
DV
DD
DV
DD
DV
DD
XTAL2
XTAL1
2-PIN HEADER FOR
EMULATION ACCESS
(NORMALLY OPEN)
DOWN LOAD/DEBUG
ENABLE JUMPER
(NORMALLY OPEN)
ANALOG
INPUT
V
REF
V
REF
OUTPUT
V
CC
GND
T1OUT
R1IN
R1OUT
T1IN
R2OUT
T2IN
C
REF
AGND
DAC0
DAC1
1k
Ω
10
Ω
02748-A-065
Figure 59. Typical ADuC814 System Connection Diagram
Single-Pin Emulation Mode
Also built into the ADuC814 is a dedicated controller for single-
pin in-circuit emulation (ICE) using standard production
ADuC814 devices. In this mode, emulation access is gained by
connection to a single pin, again the DLOAD pin is used for this
function. As described previously, this pin is either high to
enable entry into serial download and serial debug modes or
low to select normal code execution. To enable single-pin
emulation mode, however, users need to pull the DLOAD pin
high through a 1 kΩ resistor. The emulator then connects to the
2-pin header. To be compatible with the standard connector
that 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. 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).