ADXL180
Rev. 0 | Page 17 of 56
V
BP
DEVICE 1
V
BN
V
BN
V
BC
Synchronous Single Device Point-to-Point Topology
A single device is wired in the point-to-point configuration as
shown in Figure 13. The standard use of this configuration is
with no delay devices. It is possible to use this topology with
fixed delay devices as well, such as if line noise reduction after a
sync pulse transmission is desired.
CENTER
MODULE
NC
NC
07
54
4
-03
1
Figure 13. Single Device—Synchronous Communication
SYNCHRONOUS COMMUNICATION MODE—DUAL
DEVICE
The ADXL180 can be used in a dual device synchronous
communication mode. This mode allows a maximum of two
ADXL180 devices to share a single pair of wires from the
control module for power and communications. This is
accomplished using time division multiplexing where each
device transmits its data during a known time slot. The time
slot used by each device is determined by the delay time from
detection of a synchronization pulse to the beginning of data
transmission. The data transmission delay time is selectable in
the configuration registers. The following discussion uses the
convention that the first time slot is named Time Slot A and the
second time slot is named Time Slot B (see Figure 14). The two
ADXL180 devices can be wired in either a parallel or series
mode as described in the following sections. If a synchronization
pulse is not detected, no data is sent. This is true for all initiali-
zation phases and normal run-time operation. Note that the
minimum synchronization pulse period is
t
SPD
+
t
DLY
+
t
M
+
t
B
