ISL97698

FN8417 Rev.1.00

Page 11 of 21

Sep 7, 2017

Write Operation

Address Byte, a Data Byte, and a STOP condition. After each valid byte is sent, the ISL97698 (slave) responds with an ACK. When the

Write transaction is completed, the Master should generate a STOP condition. For sent data to be latched by the ISL97698, the STOP

condition should occur after a full byte (8-bits) is sent and ACK. If a STOP is generated in the middle of a byte transaction, the data will

Read Operation

A READ sequence requires the Master to first write to the ISL97698 to indicate the Register Address/pointer to read from. Send a

START condition, followed by a valid Device Address Byte with the R/W set to ‘0’, and then a valid Register Address Byte. Then the

Master generates either a Repeat START condition, or a STOP condition followed by a new START condition, and a valid Device Address

Byte with the R/W bit set to ‘1’. Then the ISL97698 is ready to send data to the Master from the requested Register Address.

The ISL97698 sends out the Data Byte by asserting control of the SDA pin while the Master generates clock pulses on the SCL pin.

When transmission of the desired data is complete, the Master generates a NACK condition followed by a STOP condition, and this

WRITE

DATA

SDA

(from Master)

SDA

(from Slave)

SCL

(from Master)

76 54 321 0

A

A 7 6 543 210

START

Device Address W

Register Pointer

7 6 543 210

A 765432 10 A

DATA

STOP

A

A

765432 10

76 54 321 0

Device Address = 27h

WRITE

REGISTER

POINTER

SDA

(from Master)

SDA

(from Slave)

SCL

(from Master)

76543210

A

7 6543 210

A

A

7 6543 210 A

READ

DATA

SDA

(from Master)

SDA

(from Slave)

SCL

(from Master)

76543210 A

START

Device Address R

START

Device Address W

Register Pointer

STOP

NOTE: First send register pointer to

indicate the READ-back starting location

A

This STOP condition is optional (not

required) to do READ-back. The device

also supports repeated STARTs.

76543 21 0 A

(No ACK)

DATA

STOP

7654 32 10

A

76 5432 10

Device Address = 27h

A

76543210

Device Address = 27h