DS2436 Dallas Semiconducotr, DS2436 Datasheet - Page 19

• Manufacturer Part Number: DS2436
• Description: Battery ID/Monitor Chip
• Manufacturer: Dallas Semiconducotr

12. The bus master reads the remainder of the ROM bits for ROM1 and communicates to the underlying
13. The bus master starts a new ROM search by repeating steps 1 through 3.
14. The bus master writes a 1-bit. This deselects ROM1 and ROM4 for the remainder of this search pass,
15. The bus master executes two read time slots and receives two 0s.
16. The bus master writes a 0-bit. This deselects ROM3, and leaving only ROM2.
17. The bus master reads the remainder of the ROM bits for ROM2 and communicates to the underlying
18. The bus master starts a new ROM search by repeating steps 13 through 15.
19. The bus master writes a 1-bit. This deselects ROM2, leaving only ROM3.
20. The bus master reads the remainder of the ROM bits for ROM3 and communicates to the underlying
Note the following:
The bus master learns the unique ID number (ROM data pattern) of one 1-Wire device on each ROM
Search operation. The time required to derive the part’s unique ROM code is:
The bus master is therefore capable of identifying 75 different 1-Wire devices per second.
MEMORY FUNCTION COMMANDS
The following command protocols are summarized in Table 3.
PAGE 1 THROUGH PAGE 3 COMMANDS
Read Scratchpad [11h]
This command reads the contents of the scratchpad RAM on the DS2436. This command is followed by a
start byte address. After issuing this command and providing the start address, the user may begin reading
the data. The user may read 32 bytes of data through the end of each scratchpad space, with any reserved
data bits reading all logic 1s. If reading occurs through the end of a page, the Bus Master may issue eight
additional read time slots and the DS2436 will respond with an 8-bit CRC of all data bytes read from the
initial starting byte through the last byte of the page. After the CRC is received by the Bus Master, any
subsequent read time slots will appear as logical 1s until a reset pulse is issued.
Write Scratchpad [17h]
This command writes to the scratchpad RAM on the DS2436. This command is followed by a start byte
address. After issuing this command and providing the start address, the user may begin writing data to
the DS2436 scratchpad at the starting byte address through the end of the 32-byte scratchpad space.
logic if desired. This completes the second ROM search pass, in which another of the ROMs was
found.
leaving only ROM2 and ROM3 coupled to the system.
logic if desired. This completes the third ROM search pass, in which another of the ROMs was found.
logic if desired. This completes the fourth ROM search pass, in which the last of the ROMs was
found.
960 s + (8 + 3 x 64) 61 s = 13.16 ms
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DS2436