DS2413: 1-Wire Dual Channel Addressable Switch
PIO ACCESS READ EXAMPLE
Read the state of the PIOs 3 times.
With only a single DS2413 connected to the bus master, the communication looks like this:
MASTER MODE
DATA (LSB FIRST)
(Reset)
COMMENTS
TX
RX
TX
TX
RX
TX
RX
Reset pulse
(Presence)
CCh
Presence pulse
Issue “Skip ROM” command
Issue “PIO Access Read” command
Read 3 PIO samples
Reset pulse
F5h
<3 data bytes>
(Reset)
(Presence)
Presence pulse
PIO ACCESS WRITE EXAMPLE
Set both PIOs to 0 and then set PIOA to 1. Both PIOs are pulled high to VCC or VPUP by a resistor.
With only a single DS2413 connected to the bus master, the communication looks like this:
MASTER MODE
DATA (LSB FIRST)
COMMENTS
TX
RX
TX
TX
TX
TX
RX
RX
TX
TX
RX
RX
TX
RX
(Reset)
(Presence)
CCh
Reset pulse
Presence pulse
Issue “Skip ROM” command
Issue “PIO Access Write” command
Write new PIO output state
Write inverted new PIO output state
Read confirmation byte
Read new PIO pin status
Write new PIO output state
Write inverted new PIO output state
Read confirmation byte
5Ah
FCh
03h
AAh
F0h
FDh
02h
AAh
C3h
Read new PIO pin status
Reset pulse
(Reset)
(Presence)
Presence pulse
Note: Usually, the PIO pin state and PIO Output Latch State are the same. To read from a PIO, the PIO Output
Latch must be 1. If the PIO pin is then pulled low by a switch or external circuitry, the output latch state and pin
state are different.
PACKAGE INFORMATION
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to
www.maxim-ic.com/DallasPackInfo.)
Maxim/Dallas Semiconductor cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim/Dallas Semiconductor
product. No circuit patent licenses are implied. Maxim/Dallas Semiconductor reserves the right to change the circuitry and specifications without notice at any
time.
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© 2005 Maxim Integrated Products S Printed USA
MAXIM is a registered trademark of Maxim Integrated Products, Inc. DALLAS is a registered trademark of Dallas Semiconductor
Corporation
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