The following pause pulse modes are available:

•

no additional pause pulse

•

additional pause pulse of minimum 12 UT generated to guarantee minimum firmware execution time between

two protocol frames

•

additional pause pulse of minimum 12 UT generated for an overall fixed frame length of 312 UT for all frame

formats

5.2.3

SPC Interface

The sensor supports a SPC (Short PWM Code) interface according to version 1.0 with additional enhancements.

 

SPC interface description

The Short PWM Code (SPC) is a synchronized data transmission based on the SENT protocol (Single Edge Nibble

Transmission) defined by SAE J2716. As opposed to SENT, which implies a continuous transmission of data, the SPC

protocol transmits data only after receiving a specific trigger pulse from the microcontroller. The required length of

the trigger pulse depends on the sensor number, which is configurable. SPC allows the operation of up to four sensors

on one bus line.

For the SPC interface the push-pull setting with controlled slopes is used (the push-pull mode is only active during the

slope controlled mode). In this configuration, the sensor has controlled rising and falling slopes. Between the slope

controlled transitions the HIGH level is maintained by the external pull-up resistor. Once the SPC protocol telegram is

sent, the sensor goes in to receiving mode (OUT Pin in Tri-sate mode) and waits until a valid trigger signal is received.

The sensor is available for the next sample after the falling edge of the end pulse. The sensor’s sampling time is at the

beginning of the synchronization period, i.e. when a correct trigger is received.

As in SENT, the time between two consecutive falling edges defines the value of a 4-bit nibble representing numbers

between 0 and 15. The transmission time therefore depends on the transmitted data values. All values are defined

using a unit time frame concept.

 

SPC frame

The protocol consists of the following nibbles:

•

A trigger pulse from the master (microcontroller), which initiates the data transmission

•

A synchronization period of 56 UT

•

A status nibble of 12-27 UT, with optional short serial message transmission

•

3 or 4 data nibbles of 12-27 UT, transmitting the angle value or the angle speed (configurable in EEPROM)

•

Optional 2 temperature nibbles of 12-27 UT each (configurable in EEPROM)

•

Optional 1 nibble (4 bit) rolling counter of 12-27 UT

•

A CRC nibble of 12-27 UT (configurable in EEPROM)

•

An end pulse to terminate the SPC transmission (12 UT)

Synchronisation

Frame

Trigger Nibble

µC Activity

Sensor Activity

90 UT

56 UT

12 … 27 UT

12 … 27 UT

12 … 27 UT

12 … 27 UT

12 … 27 UT

12 UT

Status Nibble

Data Nibble 1

Data Nibble 3

Data Nibble 2

CRC

End

pulse

Figure 13

SPC frame with 3 data nibbles

TLE49SR

Datasheet

5  Specific module descriptions

Datasheet

24

Rev. 1.1.1

2024-03-13