BQ2023_16 Datasheet, PDF (11/32 Pages) Texas Instruments – SINGLE-WIRE ADVANCED BATTERY MONITOR IC

Not Recommended for New Designs
bq2023
SINGLEĆWIRE ADVANCED BATTERY MONITOR IC
FOR CELLULAR AND PDA APPLICATIONS
SLUS480B – MAY 2001
APPLICATION INFORMATION
functional description (continued)
memory
ID ROM
The bq2023 has 64 bits of ID ROM as shown in Table 5. Forty-eight bits of this data field and the family code
can be factory programmed with a unique and secure product serialization. Contact Texas Instruments for
details.
Table 5. 64-Bit ID ROM
8-BIT CRC CODE
MSB
LSB
48-BIT SERIAL NUMBER
MSB
LSB
8-BIT FAMILY CODE
MSB
LSB
flash
Table 6 shows the memory map of the 224 x 8-bit flash section of the bq2023. The flash memory is configured
into seven 32-byte pages. To modify the flash, data are first written to the communication buffer with the write
data-memory command and then verified by reading an 8-bit CRC (cyclic redundancy check) from the bq2023
that confirms proper receipt of the data. These are then programmed into flash by issuing the programming
verification code. For further details on reading and programming the flash, refer to the memory function
commands section of this data sheet.
Table 6. 224 Bytes Flash Data Memory Map
ADDRESS (HEX)
00C0–00DF
00A0–00BF
0080–009F
0060–007F
0040–005F
0020–003F
0000–001F
PAGE
Page 6
Page 5
Page 4
Page 3
Page 2
Page 1
Page 0
pack removal detection
The PDET input pin can detect removal of the battery pack from the device it is powering. Also, it can ensure
that external devices driven by the STAT output are not active after a battery pack is removed. When the PDET
input is low, the bq2023 immediately enters sleep mode and turns off the open-drain output of the STAT pin.
SDQ serial communication
The host reads memory or registers, and programs the bq2023 through a hierarchical command structure.
Figure 8 illustrates this command structure and shows that ROM function commands select the bq2023 before
the registers or memory can be read or modified. A successful completion of the command selects or activates
the bq2023, allowing it to respond to further commands. All bytes sent and received by the bq2023 are
transmitted least significant bit first.
To validate the data transmitted from the bq2023, the host may generate a CRC value from the data as they
are received. This generated value is compared to the CRC value transmitted by the bq2023. If the two CRC
values match, the transmission is error-free. The equivalent polynomial function of this CRC is X⁸ + X⁵ + X⁴ +
1. For more details, see the CRC generation section of this data sheet.
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