Datasheet

DocID028475 Rev 7 39/114

LSM6DSL Digital interfaces

114

The slave address is completed with a Read/Write bit. If the bit is ‘1’ (Read), a repeated

START (SR) condition must be issued after the two sub-address bytes; if the bit is ‘0’ (Write)

the master will transmit to the slave with direction unchanged. Table 12 explains how the

SAD+Read/Write bit pattern is composed, listing all the possible configurations.

Table 13. SAD+Read/Write patterns

Data are transmitted in byte format (DATA). Each data transfer contains 8 bits. The number

of bytes transferred per transfer is unlimited. Data is transferred with the Most Significant bit

(MSb) first. If a receiver can’t receive another complete byte of data until it has performed

some other function, it can hold the clock line, SCL LOW to force the transmitter into a wait

state. Data transfer only continues when the receiver is ready for another byte and releases

the data line. If a slave receiver doesn’t acknowledge the slave address (i.e. it is not able to

receive because it is performing some real-time function) the data line must be left HIGH by

the slave. The master can then abort the transfer. A LOW to HIGH transition on the SDA line

while the SCL line is HIGH is defined as a STOP condition. Each data transfer must be

terminated by the generation of a STOP (SP) condition.

In the presented communication format MAK is Master acknowledge and NMAK is No

Master Acknowledge.

Command SAD[6:1] SAD[0] = SA0 R/W SAD+R/W

Read

110101

0 1 11010101 (D5h)

Write

110101

0 0 11010100 (D4h)

Read

110101

1 1 11010111 (D7h)

Write

110101

1 0 11010110 (D6h)

Table 14. Transfer when master is writing one byte to slave

Master ST SAD + W SUB DATA SP

Slave SAK SAK SAK

Table 15. Transfer when master is writing multiple bytes to slave

Master ST SAD + W SUB DATA DATA SP

Slave SAK SAK SAK SAK

Table 16. Transfer when master is receiving (reading) one byte of data from slave

Master ST SAD + W SUB SR SAD + R NMAK SP

Slave SAK SAK SAK DATA

Table 17. Transfer when master is receiving (reading) multiple bytes of data from slave

Master ST SAD+W SUB SR SAD+R MAK MAK NMAK SP

Slave SAK SAK SAK DATA

DAT

DATA