Datasheet
12Maxim Integrated
DS2465
DeepCover Secure Authenticator with
SHA-256 Coprocessor and 1-Wire Master Function
ABRIDGED DATA SHEET
1-Wire Port Configurations
The DS2465 allows adapting several timing parameters and the pullup resistor to the application’s needs. Each of these
parameters has its own 1-Wire Port Configuration register, located in the address range from 68h to 6Dh (Table 5). For
t
RSTL
, t
MSP
and t
W0L
the values for standard and overdrive speed can be adjusted independently. The lower nibble applies
to standard speed, the upper nibble to overdrive speed. The t
REC0
and R
WPU
settings apply at both 1-Wire speeds. The
parameter t
W1L
can be adjusted for overdrive speed only; the standard speed value us fixed. For t
REC0
, R
WPU
and t
W1L
the upper nibble has no function. See Table 6 for the conversion between binary code and parameter value.
After a device reset (power-up cycle, a low pulse at SLPZ, or initiated by the 1-Wire Master Reset command), the 1-Wire
Port Configuration registers are initialized to their default values. To change a port configuration, access the respective
register in I
2
C write mode and provide the new code as data byte. Starting at address 68h all port configurations can
be adjusted in a single write access. The new setting applies on the rising SCL edge of the data byte acknowledge bit,
provided that the 1-Wire line is not busy (1WB = 0). The upper 4 bits of the registers at 6Bh to 6Dh are not used. They
can be written, byte their value has no effect on the device operation.
Figure 4. Rising Edge Pullup During a Time Slot
Table 5. 1-Wire Port Configuration Address Details
ADDRESS BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
68h t
RSTL
Overdrive Speed (OD) t
RSTL
Standard Speed (STD)
69h t
MSP
Overdrive Speed (OD) t
MSP
Standard Speed (STD)
6Ah t
W0L
Overdrive Speed (OD) t
W0L
Standard Speed (STD)
6Bh (not used, default 0000b) t
REC0
(speed independent)
6Ch (not used, default 0000b) R
WPU
(speed independent)
6Dh (not used, default 0000b) t
W1L
Overdrive Speed (OD)
APU = 0
APU = 1
V
CC
0V
1-Wire LINE IS
DISCHARGED
t
1
t
2
t
3
V
IAPO
V
IL1MAX
t
REC0