lis302dltr8 STMicroelectronics, lis302dltr8 Datasheet - Page 20

• Manufacturer Part Number: lis302dltr8
• Description: Mems Motion Sensor 3-axis - ??2g/??8g Smart Digital Output ??piccolo?? Accelerometer
• Manufacturer: STMicroelectronics

Digital interfaces
5.2
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Table 13.
Table 14.
Table 15.
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 order to read multiple bytes, it is necessary to assert the most significant bit of the sub-
address field. In other words, SUB(7) must be equal to 1 while SUB(6-0) represents the
address of first register to read.
In the presented communication format MAK is Master Acknowledge and NMAK is No
Master Acknowledge.
SPI bus interface
The LIS302DL SPI is a bus slave. The SPI allows to write and read the registers of the
device.
The Serial Interface interacts with the outside world with 4 wires: CS, SPC, SDI and SDO.
Figure 6.
Master
Master
Slave
Slave
Master
Slave
SDO
SPC
SDI
CS
ST
ST
Transfer when master is receiving (reading) one byte of data from slave
Transfer when master is receiving (reading)
Multiple bytes of data from slave
Read and write protocol
SAD + W
SAD + W
RW
MS
DATA
AD5 AD4 AD3 AD2 AD1 AD0
SAK
SAK
SUB
SUB
MAK
SAK
SAK
SR
DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0
DI7 DI6 DI5 DI4 DI3 DI2 DI1 DI0
SR
SAD + R
DATA
SAD + R
SAK
SAK
NMAK
DATA
DATA
NMAK
LIS302DL
SP
MAK
SP