TLE7233G Datasheet, PDF (24/32 Pages) Infineon Technologies AG – SPI Driver for Enhanced Relay Control

SPI Driver for Enhanced Relay Control
SPIDER - TLE7233G
Serial Peripheral Interface (SPI)
device 1
device 2
device 3
SI
SO SI
SO SI
SO
MO
SPI
SPI
SPI
MI
MCS
MCLK
SPI_DasyChain.emf
Figure 12 Daisy Chain Configuration
In the SPI block of each device, there is one shift register where one bit from SI line is shifted in each SCLK. The
bit shifted out can be seen at SO. After 8 SCLK cycles, the data transfer for one device has been finished. In single
chip configuration, the CS line must transit from low to high to make the device accept the transferred data. In
daisy chain configuration the data shifted out at device #1 has been shifted in to device #2. When using three
devices in daisy chain, three times 8 bits have to be shifted through the devices. After that, the MCS line must
transit from low to high (see Figure 13).
MI
MO
MCS
MCLK
time
SO device 3
SI device 3
SO device 2
SI device 2
Figure 13 Data Transfer in Daisy Chain Configuration
SO device 1
SI device 1
SPI_DasyChain2.emf
9.3
SPI Protocol
The SPI protocol of the TLE7233G provides two registers. The input register and the diagnosis register. The
diagnosis register contains four pairs of diagnosis flags, the input register contains the input multiplexer
configuration. After power-on reset, all register bits are cleared to 0.
SI
7
6
IN3
5
4
IN2
3
2
IN1
1
0
IN0
Datasheet
24
Rev. 1.0, 2008-02-28