DS2482-100 Dallas Semiconducotr, DS2482-100 Datasheet - Page 11

• Manufacturer Part Number: DS2482-100
• Description: Single-Channel 1-Wire Master
• Manufacturer: Dallas Semiconducotr

Figure 5. 1-Wire Reset/Presence Detect Cycle
1-Wire Single Bit
Bit Allocation in the Bit Byte
Command Code
Command Parameter
Description
Typical Use
Restriction
Error Response
Command Duration
1-Wire Activity
Read Pointer Position
Status Bits Affected
Configuration Bits Affected
bit 7
x = don’t care
V
bit 6
x
V
V
V
0V
IH1
CC
IL1
bit 5
t
F1
x
Pull-up
For presence pulse masking and pull-up details see Figure 3.
bit 4
x
RESET PULSE
87h
Bit Byte
Generates a single 1-Wire time slot with a bit value ‘V’ as specified by the
bit byte at the 1-Wire line. A ‘V’ value of 0b generates a write-zero time
slot (Figure 6), a value of 1b generates a write-one slot, which also
functions as a read-data time slot (Figure 7). In either case the logic level
at the 1-Wire line is tested at t
To perform single bit writes or reads at the 1-Wire line when single bit
communication is necessary (the exception).
1-Wire activity must have ended before the DS2482 can process this
command.
Command code and bit byte are not acknowledged if 1WB = 1 at the time
the command code is received and the command is ignored.
t
bit (MS bit) of the bit byte.
Begins maximum 262.5ns after the falling SCL edge of the MS bit of the
bit byte.
Status register (for busy polling and data reading)
1WB (set to 1 for t
SBR is updated at t
DIR (may change its state)
1WS, APU, SPU apply
bit 3
SLOT
x
t
RSTL
+ maximum 262.5ns, counted from the falling SCL edge of the first
bit 2
x
bit 1
11 of 21
SLOT
x
MSR
DS2482 pull-down
)
t
bit 0
PRESENCE/SHORT DETECT
SI
x
MSR
and SBR is updated.
t
RSTH
t
MSP
1-W Slave pull down