BTS5482SF Datasheet, PDF (46/57 Pages) Infineon Technologies AG – SPI Power Controller

SPOC - BTS5482SF
Serial Peripheral Interface (SPI)
CS Low to High transition:
• Command decoding is only done, when after the falling edge of CS exactly a multiple (1, 2, 3, …) of eight SCLK
signals have been detected. In case of faulty transmission, the transmission error flag (TER) is set and the
command is ignored.
• Data from shift register is transferred into the addressed register.
SCLK - Serial Clock:
This input pin clocks the internal shift register. The serial input (SI) transfers data into the shift register on the falling
edge of SCLK while the serial output (SO) shifts diagnostic information out on the rising edge of the serial clock.
It is essential that the SCLK pin is in low state whenever chip select CS makes any transition.
SI - Serial Input:
Serial input data bits are shift-in at this pin, the most significant bit first. SI information is read on the falling edge
of SCLK. The input data consists of two parts, control bits followed by data bits. Please refer to Section 9.5 for
further information.
SO Serial Output:
Data is shifted out serially at this pin, the most significant bit first. SO is in high impedance state until the CS pin
goes to low state. New data will appear at the SO pin following the rising edge of SCLK. Please refer to Section 9.5
for further information.
9.2
Daisy Chain Capability
The SPI of SPOC - BTS5482SF provides daisy chain capability. In this configuration several devices are activated
by the same CS signal MCS. The SI line of one device is connected with the SO line of another device (see
Figure 28), in order to build a chain. The ends of the chain are connected with the output and input of the master
device, MO and MI respectively. The master device provides the master clock MCLK which is connected to the
SCLK line of each device in the chain.
device 1
device 2
device 3
SI
SO SI
SO SI
SO
MO
SPI
SPI
SPI
MI
MCS
MCLK
Figure 28 Daisy Chain Configuration
SPI_DaisyChain .emf
Data Sheet
46
Rev. 1.0, 2013-06-05