DS2408 Maxim, DS2408 Datasheet - Page 36

• Manufacturer Part Number: DS2408
• Description: The DS2408 is an 8-channel, programmable I/O 1-Wire® chip
• Manufacturer: Maxim

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