TLE8080EM

Serial Peripheral Interface (SPI)

Data Sheet

25

Rev. 1.1, 2012-10-19

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.

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

Bit 15

MSB

Bit 0

LSB

don’t care

don’t care

clock

1

clock

2

clock

3

clock

15

clock

16

Bit 14

Bit 13

Bit 1

don’t care

Bit 0

LSB

Bit 15

MSB

Bit 14

tristate

tristate

time

time

time

time

don’t care

Bit 1

Bit 13

SCLK

SI

SO

CSN

Status

Flag