L99ASC03 datasheet(47/73 Pages) STMICROELECTRONICS

Part #	L99ASC03

Description	Brushless / sensorless 3-phase motor pre-driver for automotive applications

PDF	73 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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L99ASC03

ST-SPI Protocol

Figure 22. SPI signal description

The communication frame starts with the falling edge of the CSN (Communication Start).

SCK has to be low.

The SDI data is then latched at all following rising SCK edges into the internal shift registers.

After Communication Start the SDO will leave tristate mode and present the MSB of the data

shifted out to SDO. At all following falling SCK edges data is shifted out through the internal

shift registers to SDO.

The communication frame is finished with the rising edge of CSN. If a valid communication

took place (e.g. correct number of SCK cycles), the requested operation by the OpCode will

be performed (Write or Clear operation).

4.2

Protocol

4.2.1

SDI frame

The Data-In Frame consist of 16 bits (OpCode+Address+Data).

The first two transmitted bits (MSB, MSB-1) contain the Operation Code, which represents

the instruction which will be performed. The following 6 bits (MSB-2 to MSB-7) represent the

address on which the operation will be performed.

The subsequent byte contains the payload data.

L99ASC03 Datasheet(PDF) 47 Page - STMicroelectronics