Reliable data transmission with reduced bit error rate

1. A data transmission system comprising:

a sender that is configured to send data frames to at least one transmission line, wherein the sender comprises a sender check sum calculation unit configured to calculate a sender check sum based on the data frames sent to the at least one transmission line, wherein the calculated sender check sum is continuously updated each time a data frame is sent to the at least one transmission line, and wherein the calculated sender check sum depends on all data frames that have been sent to the at least one transmission line after a reset of the sender check sum calculation unit;

a recipient that is configured to receive the data frames from the at least one transmission line, wherein the sender and the recipient are both configured to determine a check sum based on a plurality of corresponding data frames that are sent to and, respectively, received from the at least one transmission line, wherein the recipient comprises a recipient check sum calculation unit configured to calculate a recipient check sum based on the data frames received from the at least one transmission line, wherein the calculated recipient check sum is continuously updated each time a data frame is received, and wherein the calculated recipient check sum depends on all data frames that have been received after a reset of the recipient check sum calculation unit;

a check sum comparing unit configured to receive and to compare the sender check sum determined by the sender and the corresponding recipient check sum determined by the recipient, the check sum comparing unit being further configured to signal a transmission error or initiate a safety function when the sender check sum is not equal to the recipient check sum;

a switch coupled to an output of the recipient and coupled to be activated upon receipt of a signal; and

a safety circuit coupled to the check sum comparing unit, wherein the safety circuit is configured to transmit a deactivation signal configured to prevent the switch from conducting a ON current if the check sums compared are not equal.

2. The data transmission system of claim 1 , wherein the check sum comparing unit is included in the sender, or in the recipient, or in a transmission line monitoring unit arranged separately from the sender and the recipient.

3. The data transmission system of claim 2 , wherein the check sum comparing unit is included in the sender and wherein the recipient check sum determined by the recipient is sent to the check sum comparing unit via the at least one transmission line.

4. The data transmission system of claim 2 , wherein the check sum comparing unit is included in the recipient and wherein the sender check sum determined by the sender is sent to the check sum comparing unit via the at least one transmission line.

5. The data transmission system of claim 2 , wherein the check sum comparing unit is included in the transmission line monitoring unit and wherein the sender check sum determined by the sender and the recipient check sum determined by the recipient are sent to the check sum comparing unit via the at least one transmission line.

6. The data transmission system of claim 1 , wherein the sender and the recipient check sum is a polynomial code check sum generated by a cyclic redundancy check (CRC).

7. The data transmission system of claim 6 , wherein each individual data frame includes a further check sum depending only on information included in the respective data frame.

8. The data transmission system of claim 7 , wherein the further check sum is a polynomial code check sum generated by a cyclic redundancy check, whereby the order of the further check sum is lower than the order of the check sums which are based on a plurality of corresponding data frames.

9. The data transmission system of claim 1 , wherein the sender operates as bus slave and the recipient operates as bus master.

10. The data transmission system of claim 1 , further comprising:

a serial peripheral interface (SPI) slave unit comprising the sender, the SPI slave unit configured to be coupled to a plurality of external sensors; and

a SPI master unit comprising the recipient, wherein the switch is configured to be coupled to a squib upon activation, and wherein the SPI slave unit, the SPI master unit, the switch, and the safety circuit are part of an electronic control unit system for air bag deployment.

11. A bus system comprising:

a sender that is configured to send data frames to at least one bus line;

a recipient that is configured to receive the data frames from the at least one bus line, wherein the sender and the recipient are both configured to determine a check sum based on a plurality of corresponding data frames which are sent to and, respectively, received from the at least one bus line; and

a check sum comparing unit configured to receive and to compare the check sum determined by the sender and the corresponding check sum determined by the recipient, the check sum comparing unit being further configured to signal a transmission error or to initiate a safety function when the check sums compared are not equal, wherein the sender and the recipient both comprise a check sum calculation unit that calculates a check sum based on the data frames that are sent to or, respectively, received from the at least one bus line, wherein the calculated check sums is updated each time a data frame is sent or, respectively, received, and wherein the calculated check sums depend on all data frames that have been sent or, respectively, received after a reset of the check sum calculation units;

a switch coupled to an output of the recipient and coupled to be activated upon receipt of a signal; and

a safety circuit coupled to the check sum comparing unit, wherein the safety circuit is configured to transmit a deactivation signal configured to prevent the switch from conducting a ON current if the check sums compared are not equal.

12. The bus system of claim 11 , wherein the bus system is compliant with the SPI bus standard.

13. The bus system of claim 11 ,

wherein the sender operates as bus slave and the recipient operates as bus master, and

wherein the check sum comparing unit is included in the bus master, or in the bus slave, or in a bus monitoring unit arranged separately from the bus master and the bus slave.

14. The bus system of claim 13 , wherein the check sum comparing unit is included in the bus master and wherein the bus master requests the bus slave to send the current check sum via the at least one bus line.

15. The bus system of claim 13 , wherein the check sum comparing unit is included in the bus slave and wherein the bus master sends to the bus slave the current check sum via the at least one bus line.

16. The bus system of claim 13 , wherein the check sum comparing unit is included in the bus monitoring unit, wherein the bus master requests the bus slave to send the current check sum via the at least one bus line, and wherein the bus master sends to the bus monitoring unit both check sums via the at least one bus line.

17. The bus system of claim 11 , further comprising:

a serial peripheral interface (SPI) slave unit comprising the sender, the SPI slave unit configured to be coupled to a plurality of external sensors; and

a SPI master unit comprising the recipient, wherein the switch is configured to be coupled to a squib upon activation, and wherein the SPI slave unit, the SPI master unit, the switch, and the safety circuit are part of an electronic control unit system for air bag deployment.

18. A method for transmitting data frames from a sender to a recipient over a transmission channel, the method comprising:

receiving, from the sender's end, a sender check sum based on a plurality of data frames which are sent, wherein the sender check sum is continuously updated each time a data frame is sent from the sender, and wherein the sender check sum depends on all data frames that have been sent after a reset of a sender check sum calculation unit;

receiving, from the recipient's end, a recipient check sum based on a plurality of corresponding data frames which have been received, wherein the recipient check sum is continuously updated each time a data frame is received at the recipient, and wherein the recipient check sum depends on all data frames that have been received at the recipient after a reset of a recipient check sum calculation unit;

comparing the sender check sum received from the sender's end and the corresponding recipient check sum received from the recipient's end; and

transmitting a deactivation signal configured to prevent a switch, coupled to an output of the recipient and configured to be activated upon receipt of a signal, from conducting a ON current if

the sender check sum is not equal to the recipient check sum.

19. A system comprising:

a sender that is configured to send data frames to at least one transmission line;

a recipient that is configured to receive the data frames from the at least one transmission line, wherein the sender and the recipient are both configured to determine a check sum based on a plurality of corresponding data frames that are sent to and, respectively, received from the at least one transmission line;

a check sum comparing unit configured to receive and to compare the check sum determined by the sender and the corresponding check sum determined by the recipient;

a switch coupled to an output of the recipient and coupled to be activated upon receipt of a signal; and

a safety circuit coupled to the check sum comparing unit, wherein the safety circuit is configured to transmit a deactivation signal configured to prevent the switch from conducting a ON current if the check sums compared are not equal.

20. The system of claim 19 , wherein the safety circuit is configured to transmit the deactivation signal at the same time the recipient sends the signal for activating the switch.

21. The system of claim 19 , wherein the sender is configured to send the determined check sum only when the sender receives the signal for activating the switch to be transmitted to the receiver.

22. The system of claim 19 , further comprising:

a serial peripheral interface (SPI) slave unit comprising the sender, the SPI slave unit configured to be coupled to a plurality of external sensors; and

a SPI master unit comprising the recipient, wherein the switch is configured to be coupled to a squib upon activation, and wherein the SPI slave unit, the SPI master unit, the switch, and the safety circuit are part of an electronic control unit system for air bag deployment.

23. The system of claim 19 ,

wherein the sender comprises a sender check sum calculation unit configured to calculate a sender check sum based on the data frames sent to the at least one transmission line, wherein the calculated sender check sum is continuously updated each time a data frame is sent to the at least one transmission line, and wherein the calculated sender check sum depends on all data frames that have been sent to the at least one transmission line after a reset of the sender check sum calculation unit,

wherein the recipient comprises a recipient check sum calculation unit configured to calculate a recipient check sum based on the data frames received from the at least one transmission line, wherein the calculated recipient check sum is continuously updated each time a data frame is received, and wherein the calculated recipient check sum depends on all data frames that have been received after a reset of the recipient check sum calculation unit,

wherein the check sum comparing unit is further configured to signal a transmission error or initiate a safety function when the sender check sum is not equal to the recipient check sum.