TLE8080EM Datasheet, PDF (25/39 Pages) Infineon Technologies AG – Engine Management IC for Small Engines

TLE8080EM
Serial Peripheral Interface (SPI)
There are four ways of valid access:
• Write access to the command register: the answer is 1 for the R/W bit, 00 for the address and the content of
the register
• Read access to the command register: the answer is 0 for the R/W bit, 00 for the address and the content of
the register
• Read access to the diagnosis register: the answer is 0 for the R/W bit, 01 for the address and the content of
the register
• Read access to the status register: the answer is 0 for the R/W bit, 10 for the address and the content of the
register
Any other access is recognized as an invalid message.
Status Flag Indication: after the falling edge of CSN and before the first rising edge of SCLK, the level of the SO
indicates the status of the diagnosis register:
• SO = “0”: no error condition detected; all diagnosis register bits are “0”
• SO = “1”: one or more error conditions are detected; one or more diagnosis register bits are “1”
With this feature during every SPI communication a check of the diagnosis status can be done without additional
read access of the diagnosis register.
CSN
time
SCLK
don’t care
* clock )
1
c l oc k
2
c l oc k
3
c l oc k
15
clock
16
don’t care
time
SI
don’t care
Bit 15
MSB
Bit 14
Bit 13
Bit 1
Bit 0
LSB
don’t care
time
SO
tri s tate
Status
Flag
Bit 15
MSB
Bit 14
Bit 13
Bit 1
Bit 0
LSB
*^{) active clock edge for reading data at SI}
tri s tate
time
Figure 13 SPI Protocol
SPI Answers:
• during power on reset: SPI commands are ignored, SO is always low
• after power on reset: the content of the command register is transmitted with the next SPI transmission
• during watchdog reset: SPI commands are ignored, SO has the value of the status flag
• after watchdog overflow: the content of the status register is transmitted with the first SPI transmission after
the low to high transition of NRO
• after a read or write command: the content of the selected register is transmitted with the next SPI transmission
• after an invalid communication: the content of the diagnosis register is transmitted with the next SPI
transmission
Data Sheet
25
Rev. 1.1, 2012-10-19