DS2409

102199

5 of 18

STATUS CONTROL BYTE Table 1

7

6

5

4

3

2

1

0

DATA

X

CNTR.

SEL.

MODE

X

X

X

0-2

X

don’t care

3-4

Write control: both bits must be 0 to change the status.

5

MODE

control output mode selection: 0 = auto-control mode (default), 1 = manual mode

6

CNTR.

SEL.

control output association (auto-control mode): 0 = main (default), 1 = auxiliary

7

DATA

X

Value to be written to control output (manual mode only): don’t care otherwise

STATUS INFO BYTE Table 2

7

6

5

4

3

2

1

0

MODE

CNTR.

STAT

EVNT

AUX.

EVNT

MAIN

AUX.

LEVL

AUX.

STAT

MAIN

LEVL

MAIN

STAT

0

MAIN

STAT

status of main output: 0 = active (connected to bus master), 1 = inactive

1

MAIN

LEVL

voltage sensed at main output: 0 = low, 1 = high (see note)

2

AUX.

STAT

status of auxiliary output: 0 = active (connected to bus master), 1 = inactive

3

AUX.

LEVL

voltage sensed at auxiliary output: 0 = low, 1 = high (see note)

4

EVNT

MAIN

event flag for main output: 0 = no event, 1 = negative edge sensed since inactive

5

EVNT

AUX.

event flag for aux. Output: 0 = no event, 1 = negative edge sensed since inactive

6

CNTR.

STAT

if auto-control mode: control output association, 0 = main, 1 = auxiliary

if manual mode: 0 = output transistor off, 1 = output transistor on

7

MODE

control output mode: 0 = auto-control mode, 1 = manual mode

Note: Data is valid only if the output is decoupled from the 1-Wire input.

ALL LINES OFF [66h]

This command is used to deactivate the currently active 1-Wire output and to clear both event flags or to

end a discharge cycle initiated by the Discharge Lines command. Before issuing this command, one

should read the status and check the event flags of both, the main and the auxiliary output. Otherwise one

might inadvertently clear the event flag without having taken appropriate action. If the DS2409 is in auto-

control mode, the transistor at the control output will be switched off (non-conducting). At power-on, the

device will automatically perform the All Lines Off command. In contrast to a power-on cycle, the All

Lines Off command does not clear the Mode and Control Select bits.