L9663 datasheet(26/104 Pages) STMICROELECTRONICS

26 / 104 page

Satellite interface

L9663

26/104

DocID028693 Rev 1

3.2

Manchester decoder and error detection

Basic features:



Detection of start bits "00"



Synchronization with sensor to ECU frame



Manchester decoding according to PSI5 specification (v 1.3 or v 2.x, depending on the

chosen configuration)

The Manchester decoder takes the bit stream which the receiver has as its output and

decodes the incoming data frames from this bit stream.

It can be programmed to measure the period of start bits sent by the sensors and double-

check the timing of the following data bits with respect to the synchronization given by the

start bits or to validate the data bits according to the PSI5 protocol baud rate configured by

the microcontroller. The tolerance for timing checks is 20%: in case of timing error a

Manchester error is reported.

A Manchester Decoder Error occurs if one or more of the following are true:



Start bit error outside of selected operating range



Data length error or stop bit error



Bit time error (a data bit edge is not received inside the expected time window)



Timing violation on slot when standard timeslot monitor is enabled

In case a Manchester error is detected the corresponding error code is set [v. Error codes

table, Section 3.3.2].

3.3

Receive block

This block includes the buffer for incoming sensor data and diagnostic results. It includes:



PSI5 receive registers



Sensor data buffer



Interrupt generation for the microcontroller

L9663 Datasheet(PDF) 26 Page - STMicroelectronics