READ/WRITE TIMING DIAGRAM (cont’d) Figure 6
Write-zero Time Slot
DS2401
Read-data Time Slot
60µs ≤ tLOW0 < tSLOT < 120µs
1µs ≤ tREC < ∞
RESISTOR
MASTER
DS2401
60µs ≤ tSLOT < 120µs
1µs ≤ tLOWR < 15µs
0 ≤ tRELEASE < 45µs
1µs ≤ tREC < ∞
tRDV = 15µs
tSU < 1µs
CRC GENERATION
To validate the data transmitted from the DS2401, the bus master may generate a C RC value from the
data as it is received. This generated value is compared to the value stored in the last 8 bi ts of the
DS2401. If the two CRC values match, the transmission is error-free.
The equivalent polynomial function of this CRC is: CRC = x8 + x5 + x4 + 1. Additional information about
the Maxim 1-Wire CRC is available in Application Note 27.
CUSTOM DS2401
Customization of a portion of the unique 48-bit serial number by the customer is available. Maxim will
register and assign a specific customer ID in the 12 most significant bits of the 48-bit field. The next most
significant bits are selectable by the customer as a starting value, and the least significant bits are non-
selectable and will be automatically incremented by one. Certain quantities and conditions apply for these
custom parts. Contact your Maxim sales representative for more information.
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