Figure 11. Data format (write)

As data are received by the target, they are written bit by bit to a serial/parallel register. After each data byte has

been received by the target, an acknowledge is generated, the data are then stored in the internal register

addressed by the current index.

During a read message, the contents of the register addressed by the current index is read out in the byte

following the device address byte. The contents of this register are parallel loaded into the serial/parallel register

and clocked out of the device by the falling edge of SCL.

Figure 12. Data format (read)

S

As

ADDRESS[7:0]

INDEX[7:0]

As P

0x52 (write)

S

As

ADDRESS[7:0]

Am

DATA[7:0]

P

0x53 (read)

INDEX[15:8]

As

At the end of each byte, in both read and write message sequences, an acknowledge is issued by the receiving

device (that is, the VL53L4ED for a write, and the host for a read).

A message can only be terminated by the bus controller, either by issuing a stop condition or by a negative

acknowledge (that is, not pulling the SDA line low) after reading a complete byte during a read operation.

The interface also supports auto increment indexing. After the first data byte has been transferred, the index is

automatically incremented by 1. The controller can therefore send data bytes continuously to the target until the

target fails to provide an acknowledge, or the controller terminates the write communication with a stop condition.

If the auto increment feature is used, the controller does not have to send address indexes to accompany the data

bytes.

Figure 13. Data format (sequential write)

VL53L4ED

Control interface

DS14256 - Rev 3

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