DS2437

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REGISTER COMMANDS

INSTRUCTION

DESCRIPTION

PROTOCOL

1-WIRE BUS

MASTER

STATUS AFTER

ISSUING

PROTOCOL

1-WIRE BUS DATA

AFTER ISSUING

PROTOCOL

Convert T

Initiates temperature

conversion

44h

Idle or Rx of

TB bit

{TB bit in Status

Register = 1 until

conversion complete}

Convert V

Initiates voltage A/D

conversion

B4h

Idle or Rx of

ADB bit

{ADB bit in Status

Register = 1 until

conversion complete}

NOTES:

1. Temperature conversion takes up to 1 second.

2. A/D conversion takes up to 2 ms.

3. EEPROM write takes up to 50 ms.

Sample Command Sequence Table 7

Example: Bus Master enables the ICA, CCA, and DCA on a single DS2437 and configures it such that

the CCA/DCA information is shadowed to EEPROM. The voltage A/D is configured such that the

DS2437 will perform voltage measurements on the battery (VDD) voltage.

MASTER MODE

DATA (LSB FIRST)

COMMENTS

TX

Reset

Reset Pulse

RX

Presence

Presence Pulse

TX

CCh

Skip ROM

TX

4Eh00h

Issue Write SP 00h Command

TX

0Fh

Sets ICA, CA, E2?, AD Bits Active

TX

Reset

Reset Pulse

RX

Presence

Presence Pulse

TX

CCh

Skip ROM

TX

BEh00h

Issue Read SP 00h Command

RX

<9 data bytes>

Read Scratchpad Data and CRC

TX

Reset

Reset Pulse

RX

Presence

Presence Pulse

TX

CCh

Skip ROM

TX

48h00h

Issue Copy SP 00h Command

RX

Read Slots

DS2437 returns a 1 when Copy SP is complete

TX

Reset

Reset Pulse

RX

Presence

Presence Pulse, done