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PROGRAM PROFILE BYTE

Other

Command

Codes

bq2022 Transmits

MasterIssuesReset

N

Y

bq2022A

isin

ResetState

FromROM

Command

Program

ProfileCommand?

99h

55h

SDQ SIGNALING

RESET AND PRESENCE PULSE

RESET

(SentbyHost)

PresencePulse

(Sentbybq2022A)

WRITE

bq2022A

SLUS724 – SEPTEMBER 2006

The PROGRAM PROFILE byte is read to determine the WRITE MEMORY programming sequence required by

a specific manufacturer. After issuing a ROM command, the host issues the PROGRAM PROFILE BYTE

command, 99h. Figure 12 shows the the bq2022A responds with 55h. This informs the host that the WRITE

MEMORY programming sequence is the one described in the WRITE MEMORY command section of this data

sheet.

Figure 12. PROGRAM PROFILE Command Flow

All SDQ signaling begins with initializing the device, followed by the host driving the bus low to write a 1 or 0, or

to begin the start frame for a bit read. Figure 13 shows the initialization timing, whereas Figure 14 and Figure 15

is initiated, either the host continues controlling the bus during a WRITE, or the bq2022A responds during a

READ.

If the DATA bus is driven low for more than 120

µs, the bq2022A may be reset. Figure 13 shows that if the

DATA bus is driven low for more than 480

µs, the bq2022A resets and indicates that it is ready by responding

with a PRESENCE PULSE.

Figure 13. Reset Timing Diagram

portion of the bit and then either driving the DATA bus low for a WRITE 0, or releasing the DATA bus for a

WRITE 1.

13

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