dm00054618

TN0897
Technical note
ST SPI protocol
Introduction
The document describes a standardized SPI protocol. It defines a common structure of the
communication frames and defines specific addresses for product and status information.
September 2013
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www.st.com
Contents
TN0897
Contents
1
2
General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.1
Feature list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2
Signal description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
SPI communication flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1
General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2
Command byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2.1
2.3
Global status register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.3.1
2.4
3
4
5
6
7
2/28
Operating code definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Global error flag definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Configuration register (optional) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Address mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.1
RAM address range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.2
ROM address range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Write operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1
Write command format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.2
Format of data shifted out at SDO during write cycle . . . . . . . . . . . . . . . . 18
Read operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.1
Read command format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.2
Format of data shifted out at SDO during Read cycle . . . . . . . . . . . . . . . 20
Read and clear status operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6.1
Read and clear status command format . . . . . . . . . . . . . . . . . . . . . . . . . 21
6.2
Format of data shifted out at SDO during read and clear status operation 22
Read device information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
7.1
ID-Header . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
7.2
Silicon version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7.3
Product code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7.4
SPI-Frame-ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
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TN0897
Contents
Appendix A Reference documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Appendix B Product code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
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List of tables
TN0897
List of tables
Table 1.
Table 2.
Table 3.
Table 4.
Table 5.
Table 6.
Table 7.
Table 8.
Table 9.
Table 10.
Table 11.
Table 12.
Table 13.
Table 14.
Table 15.
Table 16.
Table 17.
Table 18.
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Command byte (8 bit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Operating code definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Global Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Definition of Global Status bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Configuration register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
RAM operation code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
RAM address range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
ROM operation code. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
ROM address range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Device information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
ID-Header . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Product family . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Silicon version. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Silicon version coding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
SPI-frame-ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Frame width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Product code. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
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TN0897
List of figures
List of figures
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Figure 10.
Figure 11.
Figure 12.
Figure 13.
ST SPI signal description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
SPI signal description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Communication principle of the ST SPI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Global error flag definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Write command format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
SDO Frame composition during WRITE operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Write operation - 16 bit frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Read command format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
SDO Frame composition during READ operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Read operation - 16 bit frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Read and clear status command format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
SDO Frame composition during READ and CLEAR operation. . . . . . . . . . . . . . . . . . . . . . 22
Read and clear status operation - 16 bit frame. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
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General description
TN0897
1
General description
1.1
Feature list
●
Standardized communication frame structure
●
Variable frame width
●
Global status information available in every communication frame
●
In-frame response
●
Pre-defined address assignment
●
Fail-safe concept
●
●
1.2
–
Robust communication protocol
–
Bus fault detection
–
Global failure Indication
Product information
–
Product name and family
–
Silicon version
Plug & play concept (standardized access to product information)
Signal description
Serial Clock (SCK): this input signal provides the timing of the serial interface. Data present
at Serial Data Input (SDI) is latched on the rising edge of Serial Clock (SCK). Data on Serial
Data Out (SDO) is shifted out at the falling edge of Serial Clock (SCK).
Serial Data Input (SDI): this input is used to transfer data serially into the device. It receives
the data to be written. Values are latched on the rising edge of Serial Clock (SCK).
Serial Data Output (SDO): this output signal is used to transfer data serially out of the
device. Data is shifted out on the falling edge of Serial Clock (SCK).
SDO also reflects the status of the <Global Error Flag> (Bit 7 of the <Global Status
Register>) while CSN is low and no clock signal is present
Chip Select Not (CSN): when this input signal is High, the device is not selected and Serial
Data Output (SDO) is high impedance. Driving this input Low enables the communication.
The communication must start and stop on a Low level of Serial Clock (SCK).
Failure Status (FSTAT) (optional): the <FSTAT> pin reflects the status of the <Global Error
Flag> (Bit 7 of the <Global Status Register>). It is an open-drain output signal so that
<FSTAT> pins of several devices can be connected to a common pull-up resistor and one
microcontroller I/O port in order to indicate a failure in the system.
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TN0897
General description
Figure 1.
ST SPI signal description
SCK
SDI
SDO
CSN
FSTAT
optional
The SPI can be driven by a microcontroller with its SPI peripheral running in following mode:
CPOL = 0 and CPHA = 0.
Figure 2.
SPI signal description
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The communication starts at the CSN transition from High to Low. SCK is initially Low.
Data at SDI must be stable at the first SCK transition from Low to High.
Data at SDO is shifted at the first falling edge of SCK.
CSN transition Low to High must occur after the specified number of clock cycles (rising and
falling edges of SCK are counted).
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SPI communication flow
TN0897
2
SPI communication flow
2.1
General description
The proposed SPI communication is based on a standard SPI interface structure using CSN
(Chip Select Not), SDI (Serial Data In), SDO (Serial Data Out/Error) and SCK (Serial Clock)
signal lines.
At device start-up the master reads the <SPI-frame-ID> register (ROM address 3EH) of the
slave device. This 8-bit register indicates the SPI frame length (16, 24, or 32 bit) and the
availability of additional features.
Each communication frame consists of an instruction byte which is followed by 1, 2 or 3 data
bytes.
The data returned on SDO within the same frame always starts with the <Global Status>
register. It provides general status information about the device. It is followed by 1, 2 or 3
data bytes (i. e. ‘In-frame-response’).
For write cycles the <Global Status> register is followed by the previous content of the
addressed register.
For read cycles the <Global Status> register is followed by the content of the addressed
register.
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SPI communication flow
Figure 3.
Communication principle of the ST SPI
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2.2
Command byte
Each communication frame starts with a command byte. It consists of an operating code
which specifies the type of operation (<Write>, <Read>, <Read and Clear>, <Read Device
Information>) and a 6 bit address. If less than 6 address bits are required, the remaining bits
are unused but are reserved.
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SPI communication flow
Table 1.
TN0897
Command byte (8 bit)
Operating code
Address
MSB
LSB
OC1
OC0
A5
A4
A3
A2
A1
A0
OCx: operating code
Ax: address
2.2.1
Operating code definition
Table 2.
Operating code definition
OC1
OC0
Meaning
0
0
<Write mode>
0
1
<Read mode>
1
0
<Read and clear status>
1
1
<Read device information>
The <Write Mode>, <Read Mode> and <Read and Clear Status> operations allow access to
the RAM of the device, i. e. to write to control registers or read status information.
<Read Device Information> allows access to the ROM area which contains device related
information such as the product family, product name, silicon version, register width and
availability of a watchdog.
Example 1
For 16-bit frames
Command Byte: 0000 1000
Data Byte: 1111 1111
Write FFH at RAM address 08H
Example 2
For 16-bit frames
Command Byte: 0111 1110
Data Byte: 0000 0000
Read register at RAM address 3EH
Example 3
For 16-bit frames
Command Byte: 1011 1110
Data Byte: 0000 0000
Read register at RAM address 3EH and clear its content at CSN low to high transition
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SPI communication flow
Example 4
For 16-bit frames
Command Byte: 1111 1110
Data Byte: 0000 0000
Read register at ROM address 3EH (i. e. <SPI-frame-ID>)
2.3
Global status register
Table 3.
Global Status Register
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Global Error
Not (Chip Reset TSD / chip Tframe / Temp
Comm Error
Flag (GEF)
OR Comm Error) overload
prewarning
Table 4.
Bit
Bit 1
Device Device
specific specific
Bit 0
Fail
Safe
Definition of Global Status bits
Description
Optional
feature
Polarity
Comment
0
Fail Safe
X
Indicates that the device is in Fail Safe Mode (1).
Active high The bit is defined as ‘0’ if no fail-safe functionality is
present in the device
1
Device specific
X
Active high See product datasheet(2)
2
Device specific
X
Active high See product datasheet(2)
3
Temp pre-warning
X
Active high
The bit is defined as ‘0’ if feature is not present.
See product datasheet
4
Thermal
Shutdown / Chip
Overload
X
Active high
The bit is defined as ‘0’ if feature is not present.
See product datasheet
5
Not (Chip Reset
OR
Communication
Error)
Chip Reset: registers have been set to default
Communication Error: see bit 6
Active low The bit is cleared automatically after a valid
communication with any register
After Power-On the bit is ‘0’ and is set to ‘1’ by a
valid SPI communication
6
Communication
Error
Bit is set if the number of clock cycles during
CSN = low does not match with the specified frame
Active high width or if any other device specific communication
error occurs.
See product datasheet(2)
7
Global Error Flag
(GEF)
Logic OR combination of all failures in the <Global
Active high Status register> and additional device specific
failures
1. Fail-safe Mode is an operating mode where the device enters a safe state. The precise definition is device
specific and is defined in the product datasheet.
2. See Appendix A: Reference documents.
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SPI communication flow
2.3.1
TN0897
Global error flag definition
The <Global Error Flag> (GEF) is a diagnosis information which is transmitted with every
communication frame. It indicates that a failure condition has been detected which can be
identified in the Status Registers.
The GEF is composed by a logical OR combination of failures notified in the <Global
Status> register and in device specific Status Registers.
Bits 1, 2 and 3 of the <Global Status> register may be maskable in the <Configuration>
register, i.e. these bits may be excluded from the GEF composition.
The clock monitor counts the number of clock pulses during a communication frame (while
CSN is low). If the number of SCK pulses does not correspond with the frame width
indicated in the <SPI-frame-ID> (ROM address 3EH) the frame is ignored and the
<Communication Error> bit in the <Global Status> register is set.
This safety function is implemented to avoid an unwanted activation of output stages by a
wrong communication frame.
If a communication error is detected during a read operation, the <Communication Error> bit
in the <Global Status> register is set, but the register read is transferred to the SDO pin. If
the number of clock cycles is smaller than the frame width, the data at SDO is truncated. If
the number of clock cycles is larger than the frame width, the data at SDO is filled with ‘0’.
If the frame width is greater than 16 bits, initial Read of <SPI-frame-ID> using a 16 bits
communication sets the <Communication Error> bit of the <Global Status> register. A
subsequent correct length transaction is necessary to correct this bit.
Due to this safety functionality a daisy chaining of SPI is not possible. Instead, a parallel
operation of the SPI bus by controlling the CSN signal of the connected ICs is
recommended.
The SPI Failure Detection identifies a short circuit condition at SDI if all bits within a received
frame are ‘0’ (short to GND) or ‘1’ (short to Vdd).
In this case the communication frame is ignored, the device enters the <Fail-Safe Mode>
and the <Fail-Safe> bit in the <Global Status> register is set.
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SPI communication flow
Figure 4.
Global error flag definition
Watchdog Trigger
Signal
Watchdog Trigger Bit:
Configuration Register
(RAM: 3FH; Bit 0)
Watchdog Failure
Watchdog
SDI
SCK
CSN
Fail Safe Events
SDI failure
detection
(device specific)
Communication
Error
Clock
Monitor
OR
SDO / Err
FSTAT
optional
Fail
Safe
GEF
Global Status Register
OR
Status Registers
(device specific)
GAPGCFT00721
The open-drain <FSTAT> pin is an optional feature which reflects the status of the <Global
Error Flag> (Bit 7 of the <Global Status> register). Several <FSTAT> pins in a system can be
connected to one microcontroller I/O port in order to indicate an error in the system. The
faulty device can then be identified by reading the <Global Error Flag> bits of all devices.
The <Global Error Flag> is also available on the SDO pin while CSN is low and the clock
signal is stable (high or low). The flag at SDO remains as long as CSN is low. This operation
does not set the <communication error> bit in the <Global Status Register>. The refreshprocedure of the GEF at SDO is device specific.
A status change during an SPI communication can cause an inconsistency in the <Global
Status> register and other Status Registers. For devices intended for safety critical
applications, precautions must be taken to avoid such inconsistencies.
2.4
Configuration register (optional)
The <Configuration> register is optional. When available, it is always accessible at RAM
address 3FH.
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SPI communication flow
Table 5.
TN0897
Configuration register
Bit 7
Bit 6
Device
specific
fault mask
Device
specific
fault mask
Bit 5
Bit 4
Device
Device
specific
specific
fault mask fault mask
Bit 3
Bit 2
Bit 1
Bit 0
Masking
Bit 3 of
<Global
Status>
register
Masking
Bit 2 of
<Global
Status>
register
Masking
Bit 1 of
<Global
Status>
register
WD
Trigger
<WD Trigger>: this Bit is reserved to trigger the watchdog. The precise procedure required
to serve the watchdog is device specific and defined in the product datasheet. The bit is
reserved if the device has no watchdog.
<Masking>: bits 1, 2 and 3 allow masking of the corresponding bit in the <Global Status>
register. If a Status Bit is masked, it is excluded from the <Global Error Flag> composition,
i. e. the information is still indicated in the <Global Status> register but it is not contributing
to the <Global Error Flag> (Bit 7 of the <Global Status> register).
1 = corresponding bit is masked, 0 = corresponding bit is not masked
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Address mapping
3
Address mapping
3.1
RAM address range
Table 6.
RAM operation code
Op Code
Operation
OC1
OC0
0
0
<Write>
0
1
<Read>
1
0
<Read and Clear Status>
Table 7.
RAM address range
RAM Address
Description
Access
3FH
<Configuration> optional
R/W
...
R
Status Registers
R
...
R/W
Control Registers
R/W
...
Reserved(1)
00H
1. Address 00H is reserved. A Write operation to this address is recognized as a SDI failure (short to GND)
and causes the device to enter Fail-Safe Mode.
The RAM memory area contains the Control Registers (Read/Write) and Status Registers
(Read). The address assignment for these registers is device specific and defined in the
product datasheet.
The register width can be 8, 16 or 24 bit and is defined in the <SPI Frame ID>.
For the <Configuration> register the eight most significant bits of the memory cell are used.
All unused RAM addresses are read as ‘0’.
3.2
ROM address range
Table 8.
ROM operation code
Op Code
Operation
OC1
OC0
1
1
<Read Device Information>
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Address mapping
TN0897
Table 9.
ROM address range
ROM
Address
Device Information
Access
3FH
Reserved(1)
3EH
<SPI frame ID>
R
04H to 3DH
Product specific
See product datasheet
R
03H
<product code 2>
R
02H
<product code 1>
R
01H
<silicon version>
R
00H
<ID Header>
R
1. ROM address 3FH is unused. An attempt to access this address is recognized as a SDI failure (short to
VDD) and causes the device to enter Fail-Safe Mode.
The register width of the ROM area is 8 bit. For products with 16 or 24 bit register width, the
eight most significant bits of the memory cell are used.
All unused ROM addresses are read as ‘0’.
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4
Write operation
Write operation
The write operation starts with a Command Byte followed by 1, 2, or 3 data bytes
(depending on the register width of the device). The number of data bytes is specified in the
<SPI-frame-ID>.
4.1
Write command format
Figure 5.
Write command format
Command byte
MSB
LSB
Op Code
0
Address
0
A5
A4
A3
A2
A1
A0
Data byte 1
MSB
D7
LSB
D6
D5
D4
D3
D2
D1
D0
Data byte 2(1)
MSB
D7
LSB
D6
D5
D4
D3
D2
D1
D0
1. Only for 24-bit SPI frame width.
A0 to A5: address bits
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Write operation
4.2
TN0897
Format of data shifted out at SDO during write cycle
Figure 6.
SDO Frame composition during WRITE operation
Global status register
Bit 7
Bit 6
Bit 5
Bit 4
Global Error Comm Not (Chip Reset TSD / chip
Flag (GEF) Error OR Comm Error) overload
Bit 3
Bit 2
Bit 1
Bit 0
Tframe
Device
specific
Device
specific
Fail
Safe
Data byte 1 - previous content of addressed register
MSB
D7
LSB
D6
D5
D4
D3
D2
D1
D0
Data byte 2 - previous content of addressed register(1)
MSB
D7
LSB
D6
D5
D4
D3
D2
D1
D0
1. Only for 24-bit SPI frame width.
Failures are indicated by activating the corresponding bit of the <Global Status> register.
The returned data byte(s) represent(s) the previous content of the accessed register.
Figure 7.
Write operation - 16 bit frame
CSN
SDI
0
0 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0
Command
NOT
(Chip
SDO
GEF
Com Res
Error OR
Comm
Err)
TSD /
Dev Dev
Chip Tframe
spec spec
OVL
Data (8 bit)
Fail
Safe
D7 D6 D5 D4 D3 D2 D1 D0
Data
Global Status
(previous content of
the register)
GAPGCFT00722
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5
Read operation
Read operation
The Read operation starts with a Command Byte followed by 1, 2, or 3 data bytes. The
number of data bytes is specified in the <SPI-frame-ID>. The content of the data bytes is
‘don’t care’. The content of the addressed register is shifted out at SDO within the same
frame (‘in-frame response’).
5.1
Read command format
Figure 8.
Read command format
Command byte
MSB
LSB
Op Code
0
Address
1
A5
A4
A3
A2
A1
A0
Data byte 1
MSB
0
LSB
0
0
0
0
0
0
0
Data byte 2(1)
MSB
0
LSB
0
0
0
0
0
0
0
1. Only for 24-bit SPI frame width.
A0 to A5: address bits
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Read operation
5.2
TN0897
Format of data shifted out at SDO during Read cycle
Figure 9.
SDO Frame composition during READ operation
Global status register
Bit 7
Bit 6
Bit 5
Bit 4
Global Error Comm Not (Chip Reset TSD / chip
Flag (GEF) Error OR Comm Error) overload
Bit 3
Bit 2
Bit 1
Bit 0
Tframe
Device
specific
Device
specific
Fail
Safe
Data byte 1 - content of addressed register
MSB
D7
LSB
D6
D5
D4
D3
D2
D1
D0
Data byte 2 - content of addressed register(1)
MSB
D7
LSB
D6
D5
D4
D3
D2
D1
D0
1. Only for 24-bit SPI frame width.
Failures are indicated by activating the corresponding bit of the <Global Status> register.
The returned data byte(s) represent(s) the content of the register to be read.
Figure 10. Read operation - 16 bit frame
CSN
SDI
0
1 A5 A4 A3 A2 A1 A0 0
0
0
0
0
0
0
0
Command
NOT
(Chip
SDO
GEF
Com Res
Error OR
Comm
Err)
TSD /
Dev
Chip Tframe
spec
OVL
Dev Fail
spec Safe
D7 D6 D5 D4 D3 D2 D1 D0
Global Status
Data (8 bit)
GAPGCFT00723
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6
Read and clear status operation
Read and clear status operation
The <Read and Clear Status> operation starts with a Command Byte followed by 1, 2, or 3
data bytes. The number of data bytes is specified in the <SPI-frame-ID>. The content of the
data bytes is ‘don’t care’. The content of the addressed status register is transferred to SDO
within the same frame (‘in-frame response’) and is subsequently cleared.
A <Read and Clear Status> command addressed to the <Configuration> register
(RAM: 3FH) clears all status registers (incl. the <Global Status> register) simultaneously
and reads back the <Configuration> register.
6.1
Read and clear status command format
Figure 11. Read and clear status command format
Command byte
MSB
LSB
Op Code
1
Address
0
A5
A4
A3
A2
A1
A0
Data byte 1
MSB
0
LSB
0
0
0
0
0
0
0
Data byte 2(1)
MSB
0
LSB
0
0
0
0
0
0
0
1. Only for 24-bit SPI frame width.
A0 to A5: address bits
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Read and clear status operation
6.2
TN0897
Format of data shifted out at SDO during read and clear
status operation
Figure 12. SDO Frame composition during READ and CLEAR operation
Global status register
Bit 7
Bit 6
Bit 5
Bit 4
Global Error Comm Not (Chip Reset TSD / chip
Flag (GEF) Error OR Comm Error) overload
Bit 3
Bit 2
Bit 1
Bit 0
Tframe
Device
specific
Device
specific
Fail
Safe
Data byte 1 - content of addressed status register or configuration register
MSB
D7
LSB
D6
D5
D4
D3
D2
D1
D0
Data byte 2 - content of addressed status register(1)
MSB
D7
LSB
D6
D5
D4
D3
D2
D1
D0
1. Only for 24-bit SPI frame width.
Failures are indicated by activating the corresponding bit of the <Global Status> register.
The returned data byte(s) represent(s) the content of the register to be read.
Figure 13. Read and clear status operation - 16 bit frame
CSN
SDI
1
0 A5 A4 A3 A2 A1 A0 0
0
0
0
0
0
0
0
Command
NOT
(Chip
SDO
GEF
TSD /
Dev
Chip Tframe
spec
Comm OVL
Com Res
Error OR
Dev Fail
spec Safe
D7 D6 D5 D4 D3 D2 D1 D0
Err)
Global Status
Content of addressed status register
or ‚Configuration’ Register (8 bit)
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7
Read device information
Read device information
Product specific information is stored in the ROM area and can be read using a dedicated
operating code (<Read Device Information>).
Table 10.
Device information
Op Code
7.1
Address
Device Information
1
3FH
Reserved
1
1
3EH
<SPI-frame-ID>
1
1
04H to 3DH
Product specific
See product datasheet
1
1
03H
<Product Code 2>
1
1
02H
<Product Code 1>
1
1
01H
<Silicon Version>
1
1
00H
<ID-Header>
OC1
OC0
1
ID-Header
Table 11.
ID-Header
Bit 7
Bit 6
Bit 5
Bit 4
Fam
Bit 3
Bit 2
Bit 1
Bit 0
ROM Address Range for <Device Information>
The <Address Range> specifies the highest ROM address which contains <Device
Information>.
The standard value if no additional information registers are present is 03H
( content of ID-Header is: XX00 0011)
The <Family Identifier> specifies the product family according to the following family codes:
Table 12.
Product family
Bit 7
Bit 6
Product family
0
0
VIPower
0
1
BCD
1
0
VIPower hybrid
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Read device information
7.2
TN0897
Silicon version
Table 13.
Bit 7
Silicon version
Bit 6
Bit 5
Bit 4
Bit 3
Reserved
Bit 2
Bit 1
Bit 0
Silicon Version
The <Silicon Version> provides information about the silicon version according to the
following table:
Table 14.
7.3
Silicon version coding
Bit3
Bit 2
Bit 1
Bit 0
Silicon version
0
0
0
0
First silicon
0
0
0
1
V2
Product code
<Product Code 1> and <Product Code 2> represent a unique set of codes to identify the
product. The code is specified in the datasheet (see Appendix B: Product code).
7.4
SPI-Frame-ID
The <SPI-frame-ID> provides information about the register width (1, 2, 3 bytes) and the
availability of additional features like <Burst Mode Read> and <watchdog>.
Table 15.
SPI-frame-ID
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
BR
WD
X
X
X
Bit 2
Bit 1
Bit 0
Frame width
BR: Burst-Mode Read (1 = Burst-Mode Read is supported)
WD: Watchdog (1 = available, 0 = not available)
Frame width: width of SPI frame (see Table 16)
Table 16.
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Frame width
Bit 2
Bit 1
Bit 0
Frame width
Command
Data
0
0
1
16 bit
8 bit
8 bit
0
1
0
24 bit
8 bit
16 bit
1
0
0
32 bit
8 bit
24 bit
Doc ID 023176 Rev 2
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Reference documents
Appendix A
Reference documents
1.
Power management IC with LIN transceiver (L99PM60J, Doc ID 18309)
2.
Power management IC with LIN and high speed CAN (L99PM62XP, Doc ID 16363)
3.
Power management IC with LIN and high speed CAN (L99PM62GXP, Doc ID 17639)
4.
Advanced power management system IC with embedded LIN and high speed CAN
transceiver supporting CAN Partial Networking (L99PM72PXP, Doc ID 022035)
5.
Door actuator driver (L99DZ80EP, Doc ID 18260)
6.
Door actuator driver (L99DZ81EP, Doc ID 022498)
7.
Octal half-bridge driver with SPI control for automotive application (L99MD01,
Doc ID 17242)
8.
Hexa half-bridge driver with SPI control for automotive applications (L99MD02,
Doc ID 16082)
9.
High efficiency constant current LED driver (L99LD01, Doc ID 18451)
10. Integrated microprocessor driven device intended for LIN controlled exterior mirrors
(L99MM70XP, Doc ID 022637)
11. SPI control diagnosis interface device for VIPower® M0-5 and M0-5E high side drivers
(L99PD08, Doc ID 15872)
12. Quad channel high-side driver VIPower® M0-6(VNQ6040S-E, Doc ID 18061)
13. Quad-channel high-side driver with 16-bit SPI interface VIPower® M0-6
(VNQ6004SA-E, Doc ID 22315)
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Product code
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Appendix B
Product code
Table 17.
Product code
Product code
Product
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PC1 hex
PC2 hex
L99PM60J
0C
4B
L99PM62XP
44
4E
L99PM62GXP
13
4B
L99PM72PXP
4B
27
L99DZ80
52
48
L99DZ81
01
55
L99MD01
3E
4E
L99MD02
3E
4E
L99LD01
31
51
L99MM70XP
48
48
L99PD08
25
50
VNQ6040S-E
1A
00
VNQ6004SA-E
1A
00
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Revision history
Revision history
Table 18.
Document revision history
Date
Revision
Changes
31-Oct-2012
1
Initial release.
23-Sep-2013
2
Updated Disclaimer.
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TN0897
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