Datasheet

DS2408
36 of 39
Control/Status register,
Source is Activity Latch ⇒ PLS = 1
Term is OR ⇒ CT = 0
RSTZ = inactive (input) ⇒ ROS = 0
Clear Power-On Reset Latch ⇒ PORL = 0
The resulting setup data for the Control/Status Register is 01h.
For each DS2408 in the application, perform the following initialization:
MASTER MODE
DATA (LSB FIRST)
COMMENTS
Step 1 TX (Reset) Reset pulse
RX
(Presence)
Presence pulse
TX
55h
Issue Match ROM command
TX <8 byte ROM ID> Send ROM ID of the device to be accessed
TX CCh
Issue Write Conditional Search Register
command
TX 8Bh TA1, target address = 8Bh
TX 00h TA2, target address = 008Bh
TX FFh Write Channel Selection Mask
TX FFh Write Channel Polarity Selection
TX 01h Write Control/Status Register
TX (Reset) Reset pulse
RX (Presence) Presence pulse
TX A5h Issue Resume command
TX F0h Issue Read PIO Registers command
TX 8Bh TA1, target address = 8Bh
TX 00h TA2, target address = 008Bh
RX <FFh, FFh, 81h> Read Registers and verify
TX (Reset) Reset pulse
RX (Presence) Presence pulse
Step 2 TX A5h Issue Resume command
TX 5Ah Issue Channel-access Write command
TX FFh Write byte to PIO
TX 00h Write inverted byte to PIO
(—) (—)
DS2408 switches off all channel output
transistors if transmission was OK
RX AAh Read for verification (AAh = success)
RX
FFh
Read PIO pin status and verify; FFh = OK
TX
(Reset)
Reset pulse
RX (Presence) Presence pulse
Step 3 TX
A5h
Issue Resume command
TX
C3
Issue Reset Activity Latch command
RX AAh Read for verification (AAh = success)
TX (Reset) Reset pulse
RX
(Presence)
Presence pulse