DS1961S-F3 Maxim Integrated Products, DS1961S-F3 Datasheet - Page 31

• Manufacturer Part Number: DS1961S-F3
• Description: IBUTTON EEPROM 1KBit SHA-1 2CAN
• Manufacturer: Maxim Integrated Products
• Series: iButton®r

Specifications of DS1961S-F3

• Rohs Information: IButton RoHS Compliance Plan
• Memory Size: 128B
• Memory Type: EEPROM
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Read-/Write-Time Slots
Data communication with the DS1961S takes place in time slots that carry a single bit each. Write-time
slots transport data from bus master to slave. Read-time slots transfer data from slave to master. The
definitions of the write- and read-time slots are illustrated in Figure 11.
All communication begins with the master pulling the data line low. As the voltage on the 1-Wire line
falls below the threshold V
base creates a slave-sampling window that stretches from t
at the sampling point determines whether the DS1961S decodes the time slot as 1 or 0. For reliable
communication the voltage has to be either below the V
the entire sampling window.
Master-to-Slave
For a write-one time slot, the master pulldown time (t
the voltage on the 1-Wire line to reach V
latest sampling point (t
For a write-zero time slot, the master pulldown time (t
voltage on the data line below V
the next time slot can start, the voltage on the data line first needs to rise above V
until the recovery time t
Slave-to-Master
A read-data time slot is very similar to a write-one time slot. The master begins a read-data time slot with
pulling the data line low. As the voltage on the 1-Wire line falls below the threshold V
starts its internal time base. The master pulldown time (t
setup time t
DS1961S holds the data line low for t
low at all.
The master samples the data line at t
time (d) on one side and t
later than t
t
communication, the master pulldown time should be as short as possible, maximizing the time for the
data line to reach V
the data line must have risen above V
MSR
. This condition determines the maximum duration of the master pulldown time. For reliable
SPDMIN
SU
, after which the DS1961S delivers a bit to its 1-Wire port. When transmitting a 0, the
. In case of a read-one, the voltage on the 1-Wire line must be able to reach V
IHMIN
SLSMAX
REC
. Before the next time slot can start, t
SPDMIN
TL
is expired.
) there needs to be a recovery time (t
, the DS1961S starts its internal time base. The tolerance of the slave time
ILMAX
on the other side. The optimum sample point for a read-zero case is no
MSR
TH
at the sampling point of a slow DS1961S, which is t
SPD
, inside a window that is determined by the sum of t
and remained there until the recovery time t
TH
. If the data bit is a 1, the DS1961S does not hold the data line
at t
SLSMIN
31 of 36
, the earliest sampling point of a DS1961S. After the
MPD1
MPD0
MPDR
ILMAX
SLSMIN
= t
= t
= t
SPDMAX
W1L
W0L
or above the maximum V
RL
to t
REC
-e + t
+ t
+ t
) before the next time slot can start.
SLSMAX
F
needs to be over and the voltage on
F
) must be long enough to cover the
) must be long enough to keep the
F
) must be short enough to allow
. The voltage on the data line
REC
TH
is expired.
and remain there
TL
TH
, the DS1961S
SLSMAX
RL
value during
and the rise
IHMASTER
. Before
at