DS2413Q+T&R Maxim Integrated Products, DS2413Q+T&R Datasheet - Page 5

• Manufacturer Part Number: DS2413Q+T&R
• Description: IC SWITCH 2CH ADDRESS 6-TDFN
• Manufacturer: Maxim Integrated Products

Specifications of DS2413Q+T&R

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

64-BIT LASERED ROM
Each DS2413 has a unique ROM Registration Number that is 64 bits long, as shown in Figure 3. The first eight bits
are a 1-Wire family code. The next 48 bits are a unique serial number. The last eight bits are a CRC (Cyclic
Redundancy Check) of the first 56 bits. The 1-Wire CRC is generated using a polynomial generator consisting of a
shift register and XOR gates as shown in Figure 4. The polynomial is X
the Dallas 1-Wire CRC is available in Application Note 27. The shift register bits are initialized to zero. Then
starting with the LSB of the family code, one bit at a time is shifted in. After the 8th bit of the family code has been
entered, then the serial number is entered. After the 48th bit of the serial number has been entered, the shift
register contains the CRC value. Shifting in the eight bits of CRC should return the shift register to all zeros.
Figure 2. Hierarchical Structure for 1-Wire Protocol
Figure 3. 64-Bit LASERED ROM
Figure 4. 1-Wire CRC Generator
X
0
STAGE
1
st
MSB
MSB
Command
Level:
X
8-Bit CRC Code
Commands (see Figure 10)
1
PIO Function Commands
STAGE
1-Wire ROM Function
2
nd
DS2413-specific
(see Figure 6)
X
2
STAGE
3
LSB
rd
X
3
MSB
STAGE
4
th
Polynomial = X
DS2413
Available
Commands:
Read ROM
Match ROM
Search ROM
Skip ROM
Resume
Overdrive Skip
Overdrive Match
PIO Access Read
PIO Access Write
48-Bit Serial Number
5 of 18
X
8
4
+ X
STAGE
5
5
th
+ X
Command
Codes:
33h
55h
F0h
CCh
A5h
3Ch
69h
F5h
5Ah
4
+ 1
8
+ X
LSB
5
X
+ X
5
MSB
STAGE
Data Field
Affected:
64-bit Reg. #, RC-Flag
64-bit Reg. #, RC-Flag
64-bit Reg. #, RC-Flag
RC-Flag
RC-Flag
RC-Flag, OD-Flag
64-bit Reg. #, RC-Flag,
PIO Pins
PIO Pins
8-Bit Family Code (3Ah)
4
6
+ 1. Additional information about
th
OD-Flag
INPUT DATA
X
6
STAGE
7
th
X
7
STAGE
LSB
LSB
8
th
X
8