sca3000-e05pwb VTI Hamlin, sca3000-e05pwb Datasheet - Page 24

• Manufacturer Part Number: sca3000-e05pwb
• Description: Sca3000 Series 3-axis Accelerometer
• Manufacturer: VTI Hamlin

4
4.1 SPI Interface
4.1.1
VTI Technologies Oy
www.vti.fi
Serial Interfaces
SPI frame format
Communication between the SCA3000 sensor and master controller is based on serial data
transfer and a dedicated interrupt line (INT-pin). Two different serial interfaces are available for the
SCA3000 sensor: SPI and I
enabled by pre-programming in the factory. The SCA3000 acts as a slave on both the SPI and I
bus.
SPI bus is a full duplex synchronous 4-wire serial interface. It consists of one master device and
one or more slave devices. The master is defined as a micro controller providing the SPI clock, and
the slave as any integrated circuit receiving the SPI clock from the master. The SCA3000 sensor
always operates as a slave device in master-slave operation mode. A typical SPI connection is
presented in Figure 5.
Figure 5. Typical SPI connection.
The data transfer uses the following 4-wire interface:
SCA3000 SPI frame format and transfer protocol is presented in Figure 6.
Figure 6. SPI frame format.
Each communication frame contains 16 bits. The first 8 bits in MOSI line contains info about the
operation (read/write) and the register address being accessed. The first 6 bits define the 6 bit
MICROCONTROLLER
SERIAL CLOCK (SCK)
MOSI
MISO
SCK
CSB
DATA OUT (MOSI)
DATA IN (MISO)
MASTER
Doc.Nr. 8257300A.07
SS0
SS1
SS2
SS3
master out slave in
master in slave out
serial clock
chip select (low active)
2
C (Phillips specification V2.1). However, only one per product is
SI
SO
SCK
CS
SI
SO
SCK
CS
SI
SO
SCK
CS
SI
SO
SCK
CS
SLAVE
SCA3000 → µC
µC → SCA3000
µC → SCA3000
µC → SCA3000
SCA3000 Series
Rev.A.07
24/ 43
2
C