Rainbow Electronics DS2482-800 - Manual (Page 11)

DS2482-800: Eight-Channel 1-Wire Master
11 of 22
Channel Select
Command Code C3h
Command Parameter Selection Code
Description
Sets the 1-Wire IO channel for subsequent 1-Wire communication
commands. NOTE: The selection code read back is different from the
code written. See the table below for the respective values.
Typical Use
Selecting a 1-Wire IO channel other that IO0; randomly selecting one of
the available 1-Wire IO channels.
Restriction
1-Wire activity must have ended before the DS2482 can process this
command.
Error Response
Command code and parameter will not be acknowledged if 1WB = 1 at the
time the command code is received and the command will be ignored.
If the selection code is not valid, the selection code will not be
acknowledged and the command will be ignored.
Command Duration
None; the channel selection register is updated on the rising SCL edge of
the selection code acknowledge bit.
1-Wire Activity None
Read Pointer Position Channel Selection Register (to verify write)
Status Bits Affected None
Configuration Bits Affected None
Valid Channel Selection Codes
Channel Selection Code (to be written) Code (read back)
Channel IO0 (default) F0h B8h
Channel IO1 E1h B1h
Channel IO2 D2h AAh
Channel IO3 C3h A3h
Channel IO4 B4h 9Ch
Channel IO5 A5h 95h
Channel IO6 96h 8Eh
Channel IO7 87h 87h
Figure 5. 1-Wire Reset/Presence Detect Cycle
Pullup DS2482 Pulldown 1-W Slave Pulldown
t
RSTL
t
RSTH
RESET PULSE PRESENCE/SHORT DETECT
V
CC
V
IH1
V
IL1
0V
t
F1
t
SI
t
MSP
For presence-pulse masking and pullup details see Figure 3.