Figure 2. 1-wire crc generator, Figure 4. bus master circuit, A) open drain b) ds2480b serial bridge – Rainbow Electronics DS2411 User Manual
Page 5
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DS2411
5 of 11
Figure 2. 1-WIRE CRC GENERATOR
X
0
X
1
X
2
X
3
X
4
X
5
X
6
X
7
X
8
POLYNOMIAL = X
8
+ X
5
+ X
4
+ 1
1st
STAGE
2nd
STAGE
3rd
STAGE
4th
STAGE
6th
STAGE
5th
STAGE
7th
STAGE
8th
STAGE
INPUT DATA
Figure 3. DS2411 EQUIVALENT CIRCUIT
100 Ω
MOSFET
Rx
Tx
V
CC
I/O
-1mA £ I
L
£ 1mA
GROUND
Figure 4. BUS MASTER CIRCUIT
a) Open Drain
b) DS2480B Serial Bridge
OPEN-DRAIN
PORT PIN
BUS MASTER
DS5000 OR 8051
EQUIVALENT
V
CC
to DS2411
Rx
Tx
R
PUP
I/O to DS2411
Ground to DS2411
R
PUP
must be between 0.3 kW and 2.2 kW. The optimal
value depends on the 1-Wire communication speed and
the bus load characteristics.
SIN (RxD)
SOUT (TxD)
UART
OR µC
START
STOP
1
0
L
M
* ONLY ONE DS9502 ESD PROTECTION DIODE WITH 5V
5V
5V OPERATION ONLY
GND
1-W
POL
V
DD
V
PP
RxD
TxD
DS2480
*
V
cc
I/O
GND
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