BQ28Z560-R1_14 Datasheet, PDF (39/61 Pages) Texas Instruments – Single Cell Li-Ion Battery Gas Gauge

Not Recommended For New Designs
bq28z560-R1
www.ti.com
SLUSBD3 – APRIL 2013
As an example, the data flash location for Manufacturer Info Block B is defined as having a Subclass = 58 and
an Offset = 32 through 63 (32 byte block). The specification of Class = System Data is not needed to address
Manufacturer Info Block B, but is used instead for grouping purposes when viewing data flash info in the
bq28z560-R1 evaluation software.
When in SEALED mode or when 0x01 BlockDataControl() does not contain 0x00, data flash is no longer
available in the manner used in UNSEALED mode. Rather than issuing subclass information, a designated
Manufacturer Information Block is selected with the DataFlashBlock() command. Issuing a 0x01, 0x02, or 0x03
with this command causes the corresponding information block (A, B, or C, respectively) to be transferred to the
command space 0x40…0x5F for editing or reading by the system. Upon successful writing of checksum
information to BlockDataChecksum(), the modified block is returned to data flash.
NOTE
Manufacturer Info Block A is read-only when in SEALED mode.
ACCESS MODES
The bq28z560-R1 provides three security modes (FULL ACCESS, UNSEALED, and SEALED) that control data
flash access permissions according to Table 19. Data flash refers to those data flash locations specified in
Table 20, that are accessible to the user. Manufacturer Information refers to the three 32-byte blocks.
SECURITY MODE
FULL ACCESS
UNSEALED
SEALED
Table 19. Data Flash Access
DATA FLASH
R/W
R/W
None
MANUFACTURER INFORMATION
R/W
R/W
R (A); R/W (B,C)
Although FULL ACCESS and UNSEALED modes appear identical, only FULL ACCESS mode allows the
bq28z560-R1 to write access-mode transition keys.
SEALING/UNSEALING DATA FLASH
The bq28z560-R1 implements a key-access scheme to transition between SEALED, UNSEALED, and FULL
ACCESS modes. Each transition requires that a unique set of two keys be sent to the bq28z560-R1 via the
Control() command. The keys must be sent consecutively, with no other data being written to the Control register
in between. Note that to avoid conflict, the keys must be different from the codes presented in the CNTL DATA
column of Table 4 subcommands.
When in SEALED mode, the [SS] bit of CONTROL_STATUS is set; but when the UNSEAL keys are correctly
received by the bq28z560-R1, the [SS] bit is cleared. When the full-access keys are correctly received, the
CONTROL_STATUS [FAS] bit is cleared.
Both Unseal Key and Full-Access Key have two words and are stored in data flash. The first word is Key 0 and
the second word is Key 1. The order of the keys sent to bq28z560-R1 are Key 1 followed by Key 0. The order of
the bytes for each key entered through the Control() command is the reverse of what is read from the part. For
an example, if the Unseal Key is 0x56781234, key 1 is 0x1234 and key 0 is 0x5678. Then Control() should
supply 0x3412 and 0x7856 to unseal the part. The Unseal Key and the Full-Access Key can only be updated
when in FULL ACCESS mode.
Copyright © 2013, Texas Instruments Incorporated
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