PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
5.10
PSoC 3/PSoC 5LP
Features
SMBus/PMBus Slave mode
SMBALERT# pin support
25 ms Timeout
Configurable SMBus/PMBus commands
Packet Error Checking (PEC) support
PSoC 4
General Description
The System Management Bus (SMBus) and Power Management Bus (PMBus) Slave
component provides a simple way to add a well-known communications method to a PSoC 3-,
PSoC 4-, or PSoC 5LP-based design.
SMBus is a two-wire interface that is often used to interconnect a variety of system management
chips to one or more host systems. It uses I2C with some extensions as the physical layer. There
is also a protocol layer, which defines classes of data and how that data is structured. Both the
physical layer and protocol layer add a level of robustness not originally embodied in the I2C
specification. The SMBus Slave component supports most of the SMBus version 2.0 Slave
device specifications with numerous configurable options.
PMBus is an extension to the more generic SMBus protocol with specific focus on power
conversion and power management systems. With some slight modifications to the SMBus
protocol, the PMBus specifies application layer commands, which are not defined in the SMBus.
The PMBus component presents all possible PMBus revision 1.2 commands and allows you to
select which commands are relevant to an application.
When to Use an SMBus and PMBus Slave
This component can be used in a design that requires an SMBus or PMBus slave
communication interface. The component handles most of the physical layer requirements in the
hardware. The rest of the work, including the protocol and memory management, is handled in
firmware.
Cypress Semiconductor Corporation
Document Number: 002-03684 Rev. **
•
198 Champion Court
•
San Jose, CA 95134-1709 • 408-943-2600
Revised December 17, 2015
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
Input/Output Connections
This section describes the various input and output connections of the SMBus and PMBus
Slave. An asterisk (*) in the list of I/Os indicates that the I/O may be hidden on the symbol under
the conditions listed in the description of that I/O.
clock – Input *
This is the clock that operates this block. On PSoC 3 and PSoC 5LP, this terminal is displayed
when the I2C Implementation parameter is set to Universal Digital Block (UDB) and the UDB
clock source parameter is set to External clock. The clock provided must be 16 times the desired
data rate as shown in the following table.
Data Rate
Clock
10 kbps
160 kHz
50 kbps
800 kHz
100 kbps
1.6 MHz
400 kbps
6.4 MHz
For PSoC 4, the terminal is visible if the Clock from terminal parameter is selected on I2C
Configuration tab. The following table shows the valid ranges for the component clock for each
data rate. You must ensure that the provided clock is within these ranges.
Data Rate
Clock Min
Clock Max
≤ 100 kbps
1.55 MHz
12.8 MHz
400 kbps
7.82 MHz
15.38 MHz
Note When setting the data rate or external clock frequency value, make sure that PSoC Creator
can provide this value using the current system clock frequency. Otherwise, a warning about the
clock accuracy range is generated while building the project. This warning contains the actual
clock value set by PSoC Creator. Choose whether the system clock or component clock should
be changed to fit the clocking system requirements and achieve an optimal value.
reset – Input *
This is the hardware reset for the UDB I2C implementation, and it applies to PSoC 3 and
PSoC 5LP only. If the active-high reset pin is held to logic high, the I2C block is held in reset and
communication over I2C stops. SDA and SCL are forced to high. This is a hardware reset only.
Software must be independently reset using the Stop() and Start() APIs. The reset input may be
left floating with no external connection. If nothing is connected to the reset line, the component
will assign it a constant logic 0.
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PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
sda (SMBDAT) – Input/Output *
This is the serial data input/output. It is a bidirectional data signal used to transmit or receive all
bus data. The pin connected to sda should be configured to have the Drive Mode parameter set
to “Open Drain, Drives Low”.
If you select the External IO buffer option on this component, the single sda bidirectional signal is
replaced by a separate input and output (sda_o and sda_i). This is necessary to enable the
multiplexing of multiple I2C buses required by certain applications.
Note The pin is buried inside the component on PSoC 4. The External IO buffer option is not
supported on PSoC 4.
scl (SMBCLK) – Input/Output *
This is the serial clock input/output. Although the slave never generates the clock signal, it may
hold the clock low, stalling the bus until it is ready to send data or ACK/NACK the latest data or
address. The pin connected to scl should be configured to have Drive Mode parameter set to
“Open Drain, Drives Low”.
If you select the External IO buffer option on this component, the single scl bidirectional signal is
replaced by a separate input and output (scl_o and scl_i). This is necessary to enable the
multiplexing of multiple I2C busses required by certain applications.
Note The pin is buried inside the component on PSoC 4. The External IO buffer option is not
supported on PSoC 4.
smbalert (SMBALERT#) – Output *
This is an optional SMBus alert signal. It displays when the Enable SMBALERT# pin option is
checked. The alert pin may be asserted/de-asserted via APIs described later. The pin connected
to smbalert should be configured as “Open Drain, Drives Low”.
Note The pin is buried inside the component on PSoC 4.
scl_timeout – Input *
This is the serial clock (scl) low timeout detection.
The PSoC 4 implementation requires a dedicated device pin for scl low timeout detection. The
pin must be connected to the SMBCLK line of the bus external to the PSoC device.
On PSoC 3 and PSoC 5LP, the component monitors the scl signal internally and does not use
this input signal.
Document Number: 002-03684 Rev. **
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SMBus and PMBus Slave
PSoC® Creator™ Component Datasheet
Schematic Macro Information
For PSoC 3 and PSoC 5LP, the PSoC Creator Component Catalog contains two schematic
macro implementations. These macros contain either the SMBus Slave or PMBus Slave
component, already connected to digital pins and a clock. The components are configured in
SMBus Slave or PMBus Slave mode respectively, and use UDB-based I2C implementations.
The pins connected to scl, sda and smbalert terminals are configured with the Drive Mode
parameter set to “Open Drain, Drives Low”. The clock frequency is set for 100 kbps data rate.
SMBus Slave Macro
PMBus Slave Macro
Component Parameters
Drag an SMBus/PMBus Slave component onto your design and double click it to open the
Configure dialog. This dialog has the following tabs with different parameters.
General Tab
The General tab provides options to configure the general settings of the SMBus/PMBus.
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PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
Load configuration
This button restores all settings, including tables, from an external file.
Keyboard shortcut – [Ctrl] [L].
Save configuration
This button saves all settings, including tables, in an external file. Keyboard shortcut – [Ctrl] [S].
Mode
This parameter specifies the mode in which the component operates: SMBus Slave (default) or
PMBus Slave. This parameter also determines the available data rate.
In PMBus Slave mode there are two options: 100 and 400 kbps.
In SMBus Slave mode there are additional 10 kbps and 50 kbps options.
Data rate
This parameter specifies the data transfer rate. The available options are dependent on the
SMBus/PMBus Mode selection. The PMBus Slave mode allows data rate values of 100 kbps
and 400 kbps. The SMBus Slave mode provides options for 10kbps, 50 kbps, 100 kbps, and 400
kbps. The default setting is 100 kbps.
Note For PSoC 4, the attainable data rate always displays the maximum value for the provided clock
source. For example, 100 kbps will be displayed for 10, 50, and 100 kbps data rate since all these
data rates have the same clock requirements. Refer to the clock input section for more information
on clock requirements.
Slave address
This parameter determines the primary address (7-bit format) of the device. The value can be
entered either in decimal or in hexadecimal (if preceded by "0x"). The customizer validates the
address to ensure that it does not conflict with any of the SMBus Slave reserved addresses.
(Default = 0x20).
Enable packet error checking
This parameter enables/disables support for SMBus packet error checking (PEC).
If selected, the component will perform the slave transfer with or without PEC, verify the
correctness of the PEC if present, and only process the message if PEC is correct. If the
received and calculated PEC bytes do not match, the component will respond as
described in Corrupted Data section later in this document.
If not selected (default), it is the host responsibility to know that PEC is not supported and
to not send a PEC byte.
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SMBus and PMBus Slave
PSoC® Creator™ Component Datasheet
Enable SMBALERT# pin
This parameter allows you to configure the optional SMBALERT# output pin for host notification.
If this option is selected, the pin becomes visible as an output on the component symbol.
The Auto mode/Manual mode options determine whether the SMBALERT# pin will
automatically de-assert after the host queries the device at the Alert Response Address. See
Appendix A of the SMBus specification for details. The SMBALERT# pin is enabled and set to
Auto mode by default. The option can be changed by the SetSmbAlertMode() API call.
In Auto mode, SMBALERT# is automatically de-asserted once the bus master successfully
reads the Alert Response Address performing a modified Receive Byte operation. It is “modified”
because the host accesses the Alert Response Address and the device responds with its
primary address; refer to the SMBus specification for more information.
In Manual mode, the component will call the HandleSmbAlertResponse() API, where user code
(in a callback function) is responsible for de-asserting SMBALERT#.
Note The Auto mode option is not recommended for multi-slave applications. The component
has no arbitration capability to determine that the highest priority (lowest address) device wins
communication rights in the case where more than one device that pulled SMBALERT# low
responds to the Alert Response address. This case results in de-asserting SMBALERT# by all
devices that pulled the pin low. The preferred method in this case is to handle SMBALERT# in
an application layer and de-assert the pin calling SetSmbAlert() API after a host reads the device
fault status for example.
The arbitration on the I2C bus relies on the wired AND connection of all devices to the I2C bus. If
more than one device tries to put information onto the bus, zero is transmitted if at least one
device sends zero onto the bus. This constrains the slave address selection for the application.
That is, the lowest address should not have ones in the address bits where higher addresses
have zeros. For example, if two 7-bit slave addresses are 0100000 and 1000000, and both
devices try to put their addresses onto the bus, the value 0000000 will be received by the host.
Paged commands array size
Determines the array size for paged commands. All paged commands share this array size.
Range=1-64. (Default=8).
SMBus Box
The SMBus box configures the optional SMBus features. It is present only in SMBus Slave
Mode.
The Enable receive byte protocol check box enables/disables support for the SMBus
Receive Byte protocol defined in the SMBus specification. If unchecked, any Receive Byte
transaction is treated as a bus error. If checked, the component calls the
GetReceiveByteResponse() API to determine the response byte for Receive Byte
requests.
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PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
The Support PAGE Command check box allows you to have access to the PAGE
command while in SMBus Slave mode.
The Support QUERY Command checkbox allows you to have access to the QUERY
command while in SMBus Slave mode.
If either the PAGE or QUERY commands are enabled, then these commands are added to the
command list on the Custom Commands tab. The properties for these commands are based on
the PMBus specification, but a customization of the command codes is also possible.
The default values for this box are: Enable receives byte protocol unchecked, Support PAGE
Command enabled, Command Code=0x00, Support QUERY command enabled, Command
Code=0x1A.
PMBus Commands Tab
This tab is available when the PMBus Slave option is selected for the Mode parameter. It
presents the entire list of defined commands from the PMBus specification. The pre-filled
information includes the command name, numeric code, and command type. You may select the
commands to be supported by selecting/unselecting an Enable check box associated with each
command. Command name, Code, and Type are read-only fields.
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SMBus and PMBus Slave
PSoC® Creator™ Component Datasheet
Toolbar
Copy/Paste – These commands allow you to copy selected table rows and paste them to
the Custom Commands tab.
Note The Paste function cannot be used on any other tab.
Import/Export table – These options allow you to save and restore the settings to/from
an external file. This allows for easy loading of preset profiles and retention of custom
settings.
Hide disabled commands – This option allows you to hide commands that are not
enabled.
Import all/Export all – These commands allow you to save and restore the settings for
both PMBus Commands and Custom Commands tables to an external file.
Format
This parameter specifies the data format for this command. This format is used by the
component in formulating the response to the QUERY command. The possible format values
available in the QUERY command are Non-numeric, Linear, Signed, Direct, Unsigned, VID Mode
and Manufacturer. This field is only used for purposes of the QUERY command, as the
component does not perform any actual numeric conversion. The default setting is Non-numeric.
Size
For Block and Process Call type commands, you may edit the Size field to specify the size of the
data element. This size does not include the size/count byte that the SMBus protocol appends to
the beginning of block transfers. This field can only be edited for Block or Process Call
commands. For all other types, the Size field comes from the PMBus specification. The default
value is 16.
Paged
This parameter indicates whether this command is Paged (i.e., indexed) or not. For commands
that are paged, the component automatically generates an array for that command in the register
store. The size of the array is determined by the Paged command’s array size parameter. For
Auto Read/Write config, the component automatically indexes to the correct array element of a
Paged parameter based on the current PMBus page (as selected by the last Page command).
Read/Write config
For each command, select whether that command is readable and/or writeable via the Read
config and Write config parameters. For each, select None, Auto, or Manual (default).
None indicates the action is disabled (that is, set Write config to None for read-only).
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PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
Auto indicates that commands are handled entirely by the component without user
firmware intervention or notification. In the case of Auto write, the component
automatically copies the command data from the transfer buffer to the appropriate
variable in the Operating register store for the command. In the case of Auto read, the
component automatically copies the data for the command from the Operating register
store to the transfer buffer and completes the transaction.
Manual indicates that commands must be handled by the user main program context out
of the component ISR context. When a manual command arrives, the component will add
it to the transaction queue and disable the interrupt. The component provides the
following APIs to process the manual commands from the main program:
GetTransactionCount(), GetNextTransaction() and CompleteTransaction(). Refer to the
Application Programming Interface section for a detailed description of each API.
Note Because of the possible asymmetry between writes and reads and the complex nature of
Process Call protocol, Auto may not be selected for commands that use that protocol.
It is more likely to enable Auto mode for a read than a write. The reason for this is that reads are
less likely to require additional actions outside of the component, where writes often will do. For
example, the PMBus over-voltage threshold command (VOUT_OV_FAULT_THRESHOLD)
would have Read config set to Auto and Write config set to Manual in most systems.
User firmware would need to take action on the write of this parameter to set up hardware for the
new threshold. However, if the PMBus host just wanted to read the currently configured value
there is no need for user firmware to get involved. An example of a Read command that might
not be configured in Auto mode would be the PMBus command READ_VOUT, which returns the
measured voltage of an output rail. User firmware would need to take a voltage measurement,
perform the unit translation and Operating register store update.
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SMBus and PMBus Slave
PSoC® Creator™ Component Datasheet
Custom Commands Tab
This tab allows you to enter all SMBus commands and any manufacturer-specific PMBus
commands.
Toolbar
Copy/Paste – These commands allow you to copy selected table rows and paste them
within the Custom Commands tab.
Note The Paste function cannot be used on any other tab.
Import/Export table – These options allow you to save and restore settings to an
external file. This allows for easy loading of preset profiles and retention of custom
settings.
Command name
The user specified name for the command. Allowed characters are A-Z (all caps), 0-9, and the
underscore "_". The maximum length is 24 characters. The first character may not be a number.
Command name duplicates are not allowed (including custom command names that duplicate
standard PMBus command names). The Command Name is blank by default.
Command code
The numeric code for this command. It is a hexadecimal value, limited to two characters.
Duplicate command codes are not allowed. This includes command codes that conflict with
enabled PMBus commands. The Command Code is left blank by default.
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PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
Type
This parameter specifies the SMBus transfer protocol/data-size used for this command. The
possible values are Send Byte, Read/Write Byte, Read/Write Word, Read/Write Block, Process
Call, and Block Process Call. It is set to Read/Write Byte as default.
Format
This parameter specifies the numeric format for this command. This format is used by the
component in formulating the response to the QUERY command. The possible format values
available in the QUERY command are Non-numeric, Linear, Signed, Direct, Unsigned, VID Mode
and Manufacturer. This field is only used for purposes of the QUERY command, as the
component does not perform any actual numeric conversion. The default setting is Non-numeric.
Size
For Block and Process Call type commands, you may edit the Size field to specify the size of the
data element. This size does not include the size/count byte that the SMBus protocol appends to
the beginning of block transfers. This field can only be edited for Block or Process Call
commands. For all other types, the Size field comes from the PMBus Specification. The default
value is 16.
Paged
This parameter indicates whether this command is paged (i.e., indexed) or not. For commands
that are paged, the component automatically generates an array for that command in the register
store. The size of the array is determined by the Paged command’s array size parameter. For
Auto Read/Write config, the component automatically indexes to the correct array element of a
Paged parameter based on the current PMBus page (as selected by the last Page command).
Num pages
The number of pages parameter will default to the total number of pages specified on the
General tab. That is, when you add a new command, the number of pages for that command will
be equal to the Paged commands array size value on the General tab. However changing the
value of the Paged commands array size parameter will not change the number of pages set for
already entered custom commands. You may elect to reduce this parameter as it applies to this
particular command. Minimum setting is 1. Maximum setting is the total number of pages
selected on the General tab. This parameter is grayed out when the Paged check box is unchecked.
Read/Write Config
For each command, select whether that command is readable and/or writeable via the Read
Config and Write Config parameters. For each, select None, Auto, or Manual (default). Refer to
Read/Write config parameter description on PMBus Commands tab for details.
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SMBus and PMBus Slave
PSoC® Creator™ Component Datasheet
I2C Configuration Tab (PSoC 3 / PSoC 5LP)
This tab allows you to configure the I2C hardware.
Implementation
This parameter determines whether the I2C hardware is implemented using Fixed Function or
UDB. The default mode is set to UDB. Refer to the Resources section later in this document for
details on device resources utilization.
Address decode
This parameter allows you to choose between software and hardware address decoding. For
most applications where only one slave address is required, hardware address decoding is
preferred. If hardware address decode is enabled, the block automatically NACKs addresses
that are not its own without CPU intervention. It automatically interrupts the CPU on correct
address reception, and holds the scl line low until CPU intervention.
Software address detection allows the component to respond to multiple addresses. That is, the
software address detection must be used to support Alert Response Address and General Call
Address. (Default = Software).
Pins
This parameter determines which type of pins to use for sda and scl signal connections. The
setting is available for the Fixed function I2C implementation only. Options: Any, I2C0, and I2C1.
(Default = Any). "Any" means general-purpose I/O (GPIO or SIO).
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PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
UDB clock source
This parameter allows you to choose between an internally configured clock and an externally
configured clock for data rate generation. When set to Internal Clock, PSoC Creator calculates
and configures the required clock frequency based on the Data rate parameter, taking into
account 16 times oversampling. In External clock mode, the component does not control the
data rate but displays the actual data rate based on the user-connected clock source.
If this parameter is set to Internal clock then the clock input is not visible on the symbol. You can
enter the desired tolerance values for the internal clock. PSoC Creator will ensure that the
accuracy of the resulting clock falls within the given tolerance range or produce a warning if the
desired clock is not achievable. Clock tolerances are specified as a percentage. The valid range
is -5% to +50%.
Enable UDB slave fixed placement
This parameter allows you to choose a fixed component placement that improves the component
performance over unconstrained placement. If this parameter is set, all of the component
resources are fixed in the top right corner of the device. This parameter controls the assignment
of pins connected to the component. The choice of pin assignment is not a determining factor for
component performance. This option is only valid if the Implementation parameter is set to UDB.
The fixed placement aspect of the component removes the routing variability. It also allows the
fixed placement to continue to operate the same as a non-fixed placed design would in a fairly
empty design.
External IO buffer
This parameter allows internal I2C bus multiplexing. The internal OE buffer is removed and
bidirectional scl and sda terminals are replaced with separate inputs (sda_i and scl_i) and
outputs (sda_o and scl_o). For more information on I2C bus multiplexing implementation, refer to
the PSoC Creator I2C Component Datasheet.
I2C Configuration Tab (PSoC 4)
This tab allows you to configure the I2C hardware.
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PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
Clock from terminal
This parameter allows choosing between an internally configured clock and an externally
configured clock for data rate generation. When the option is enabled, the component does not
control the data rate, but displays the actual data rate based on the user-connected clock source
frequency. When this option is not enabled, PSoC Creator configures the required clock source.
The clock source frequency is calculated by the component based on the Data rate parameter.
Application Programming Interface
Application Programming Interface (API) routines allow you to configure the component using
software at runtime. The following table lists and describes the interface to each function. The
subsequent sections cover each function in more detail.
By default, PSoC Creator assigns the instance name "SMBusSlave_1" to the first instance of a
component in a given design. You can rename it to any unique value that follows the syntactic
rules for identifiers. The instance name becomes the prefix of every global function name,
variable, and constant symbol. For readability, the instance name used in the following table is
"SMBusSlave."
Note Some of the component API functions are used in component ISRs and, therefore, when
building with the Keil compiler may provoke a compiler warning. To avoid this, include these
functions in the ".cyre" file.
Functions
Function
Description
SMBusSlave_Start()
Initializes and enables the SMBus component. The I2C interrupt is
enabled, and the component can respond to the SMBus traffic.
SMBusSlave_Stop()
Stops responding to the SMBus traffic. Also disables the interrupt.
SMBusSlave_Init()
This function initializes or restores the component according to the
customizer Configure dialog settings.
SMBusSlave_Enable()
Activates the hardware and begins component operation.
SMBusSlave_EnableInt()
Enables the component interrupt.
SMBusSlave_DisableInt()
Disables the interrupt.
SMBusSlave_SetAddress()
Sets the primary address.
SMBusSlave_SetAlertResponseAddress()
Sets the Alert Response Address.
SMBusSlave_SetSmbAlert()
Sets the value passed to the SMBALERT# pin.
SMBusSlave_SetSmbAlertMode()
Determines how the component responds to an SMBus master read
at the Alert Response Address.
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PSoC® Creator™ Component Datasheet
Function
SMBus and PMBus Slave
Description
SMBusSlave_HandleSmbAlertResponse()
Called by the component when it responds to the Alert Response
Address issued by the host and the SMBALERT Mode is set to
MANUAL_MODE.
SMBusSlave_GetNextTransaction()
Returns a pointer to the next transaction record in the transaction
queue. If the queue is empty, the function returns NULL.
SMBusSlave_GetTransactionCount()
Returns the number of transaction records in the transaction queue.
SMBusSlave_CompleteTransaction()
Causes the component to complete the currently pending transaction
at the head of the queue.
SMBusSlave_GetReceiveByteResponse()
Returns the byte to respond to a "Receive Byte" protocol request.
SMBusSlave_HandleBusError()
Called by the component whenever a bus protocol error occurs.
SMBusSlave_StoreUserAll()
Saves the Operating register store in RAM to the User register store
in Flash.
SMBusSlave_RestoreUserAll()
Verifies the CRC field of the User register store and then copies the
contents of the User register store to the Operating register store.
SMBusSlave_EraseUserAll()
Erase the User register store in Flash.
SMBusSlave_RestoreDefaultAll()
Verifies the signature field of the Default register store and then
copies the contents of the Default register store to the Operating
register store.
SMBusSlave_StoreComponentAll()
Update the parameters of other components in the system with the
current PMBus settings.
SMBusSlave_RestoreComponentAll()
Updates the PMBus Operating register store with the current
configuration parameters of other components in the system.
SMBusSlave_Lin11ToFloat()
Converts the argument "linear11" to floating point and returns it.
SMBusSlave_FloatToLin11()
Takes the argument "floatvar" (a floating point number) and converts
it to a 16-bit LINEAR11 value (11-bit mantissa + 5-bit exponent),
which it returns.
SMBusSlave_Lin16ToFloat()
Converts the argument "linear16" to floating point and returns it.
SMBusSlave_FloatToLin16()
Takes the argument "floatvar" (a floating point number) and converts
it to a 16-bit LINEAR16 value (16-bit mantissa), which it returns.
void SMBusSlave_Start(void)
Description:
This is the preferred method to begin component operation. SMBusSlave_Start() calls the
SMBusSlave_Init() function, and then calls the SMBusSlave_Enable() function.
Parameters:
None
Return Value:
None
Side Effects:
None
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SMBus and PMBus Slave
PSoC® Creator™ Component Datasheet
void SMBusSlave_Stop(void)
Description:
This function stops the component and disables the interrupt. It releases the bus if it was
locked up by the device and sets it to the idle state.
Parameters:
None
Return Value:
None
Side Effects:
None
void SMBusSlave_Init(void)
Description:
This function initializes or restores the component according to the customizer Configure
dialog settings. It is not necessary to call SMBusSlave_Init() because the
SMBusSlave_Start() API calls this function, which is the preferred method to begin
component operation.
Parameters:
None
Return Value:
None
Side Effects:
All registers will be set to values according to the customizer Configure dialog.
void SMBusSlave_Enable(void)
Description:
This function activates the hardware and calls EnableInt() to begin component operation. It
is not necessary to call SMBusSlave_Enable() because the SMBusSlave_Start() API calls
this function, which is the preferred method to begin component operation. If this API is
called, SMBusSlave_Start() or SMBusSlave_Init() must be called first.
Parameters:
None
Return Value:
None
Side Effects:
None
void SMBusSlave_EnableInt(void)
Description:
This function enables the component interrupt. It is not required to call this API to begin the
component operation since it is called in SMBusSlave_Enable().
Parameters:
None
Return Value:
None
Side Effects:
None
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PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
void SMBusSlave_DisableInt(void)
Description:
This function disables the component interrupt. This function is not normally required
because the I2C_Stop() function disables the interrupt. The component does not operate
when the interrupt is disabled.
Parameters:
None
Return Value:
None
Side Effects:
If the interrupt is disabled while the component is still running, it can cause the bus to lock
up.
void SMBusSlave_SetAddress(uint8 address)
Description:
This function sets the primary slave address of the device.
Parameters:
uint8 address: primary device address. This value can be any address between 0 and 127
(0x00 to 0x7F) except reserved SMBus addresses. The address is the 7-bit right-justified
slave address and does not include the R/W bit.
Return Value:
None
Side Effects:
None
void SMBusSlave_SetAlertResponseAddress(uint8 address)
Description:
This function sets the Alert Response Address.
Parameters:
uint8 address: Alert Response Address. This value can be any address between 0 and 127
(0x00 to 0x7F). The address is the 7-bit right-justified slave address and does not include
the R/W bit. By default the address is set to 0xC0 to correspond with the SMBus
specification.
Return Value:
None
Side Effects:
None
void SMBusSlave_SetSmbAlert(uint8 assert)
Description:
This function sets the value to the SMBALERT# pin. As long as SMBALERT# is asserted,
the component will respond to master read’s to the Alert Response Address. The response
will be the device’s primary slave address. Depending on the mode setting, the component
will automatically de-assert SMBALERT#, call the
SMBusSlave_HandleSmbAlertResponse() API, or do nothing.
Parameters:
uint8: value to set; options 0 or 1;
Return Value:
None
Side Effects:
None
Document Number: 002-03684 Rev. **
Page 17 of 47
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
void SMBusSlave_SetSmbAlertMode(uint8 alertMode)
Description:
This function determines how the component responds to an SMBus master read at the
Alert Response Address. When SMBALERT# is asserted, the SMBus master may
broadcast a read to the global Alert Response Address to determine which SMBus device
on the shared bus has asserted SMBALERT#.
In Auto mode, SMBALERT# is automatically de-asserted once the component
acknowledges the Alert Response Address.
In Manual mode, the component will call the API
SMBusSlave_HandleSmbAlertResponse() where user code (in a callback function) is
responsible for de-asserting SMBALERT#.
In DO_NOTHING mode, the component will take no action.
Parameters:
uint8: alertMode a byte that defines SMBALERT pin mode.
Value
Description
SMBusSlave_DO_NOTHING
Do nothing with SMBALERT# pin
SMBusSlave_AUTO_MODE
Automatically deassert SMBALERT# pin
SMBusSlave_MANUAL_MODE
User code is responsible for deasserting
SMBALERT# pin
Return Value:
None
Side Effects:
None
void SMBusSlave_HandleSmbAlertResponse(void)
Description:
This function is called by the component when it responds to the Alert Response Address
and the SMBALERT Mode is set to MANUAL_MODE. This function defines a callback
function where the user inserts code to run after the component has responded. For
example, the user might update a status register and de-assert the SMBALERT# pin.
Parameters:
None
Return Value:
None
Side Effects:
None
Page 18 of 47
Document Number: 002-03684 Rev. **
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
TRANSACTION_STRUCT* SMBusSlave_GetNextTransaction(void)
Description:
This function returns a pointer to the next transaction record in the transaction queue. If the
queue is empty, the function returns NULL. Only Manual Reads and Writes will be returned
by this function, as the component will handle any Auto transactions on the queue. In the
case of Writes, it is the responsibility of the user firmware servicing the Transaction Queue
to copy the "payload" to the register store. In the case of Reads, it is the responsibility of
user firmware to update the contents of the variable for this command in the register store.
For both, call SMBusSlave_CompleteTransaction() to free the transaction record.
Note that for Read transactions, the length and payload fields are not used for most
transaction types. The exception to this is Process Call and Block Process Call, where the
block of data from the write phase will be stored in the payload field.
Parameters:
None
Return Value:
Pointer the next transaction record
Side Effects:
None
uint8 SMBusSlave_GetTransactionCount(void)
Description:
This function returns the number of transaction records in the transaction queue.
Parameters:
None
Return Value:
uint8: Number of records in the transaction queue. The count will only be 0 or 1.
Side Effects:
None
void SMBusSlave_CompleteTransaction(void)
Description:
This function causes the component to complete the currently pending transaction at the
head of the queue. The user firmware transaction handler calls this function after
processing a transaction. This alerts the component code to copy the register variable
associated with the pending read transaction from the register store to the data transfer
buffer so that the transfer may complete. It also advances the queue. Must be called for
reads and writes.
Parameters:
None
Return Value:
None
Side Effects:
None
Document Number: 002-03684 Rev. **
Page 19 of 47
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
uint8 SMBusSlave_GetReceiveByteResponse(void)
Description:
This function is called by the component ISR to determine the response byte when it
detects a "Receive Byte" protocol request. This function invokes a callback function where
the user may insert their code to override the default return value of this function – which is
0xFF. This function will be called in ISR context. Therefore, user code must be fast, nonblocking, and may only call re-entrant functions.
Parameters:
None
Return Value:
uint8: User-specified status byte
Value
SMBusSlave_RET_UNDEFINED
Side Effects:
Description
Default return status
None
void SMBusSlave_HandleBusError(uint8 errorCode)
Description:
This function is called by the component whenever a bus protocol error occurs. Examples
of bus errors would be: invalid command, data underflow, and clock stretch violation. This
function is only responsible for the aftermath of an error since the component will already
handle errors in a deterministic manner. This function is primarily for the purpose of
notifying user firmware that an error has occurred. For example, in a PMBus device this
would give user firmware an opportunity to set the appropriate error bit in the
STATUS_CML register.
Parameters:
uint8 errorCode:
Value
Description
SMBusSlave_ERR_READ_FLAG
Read Flag was incorrectly set
SMBusSlave_ERR_RD_TOO_MANY_BYTES
Host attempts to read too many bytes
SMBusSlave_ERR_WR_TOO_MANY_BYTES Host attempts to write too many bytes
SMBusSlave_ERR_UNSUPPORTED_CMD
Received command is unsupported
SMBusSlave_ERR_INVALID_DATA
Received data is invalid
SMBusSlave_ERR_TIMEOUT
Bus reset timeout occured
SMBusSlave_ERR_CORRUPTED_DATA
Received PEC does not match
Return Value:
None
Side Effects:
None
Page 20 of 47
Document Number: 002-03684 Rev. **
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
uint8 SMBusSlave_StoreUserAll(const uint8 * flashRegs)
Description:
This function saves the Operating register store to the User register store in Flash. The
CRC field in the register store data structure is recalculated and updated prior to the save.
This function does not perform storing anything to Flash by default. Instead it executes a
user callback function where the user can implement an algorithm for storing Operating
register store to Flash.
Parameters:
flashRegs: A pointer to a location in Flash where Operating register store (RAM) should be
stored.
Return Value:
uint8: status
Value
Side Effects:
Description
CYRET_SUCCESS
Action completed successfully
CYRET_BAD_PARAM
Invalid parameter value
None
uint8 SMBusSlave_RestoreUserAll(const uint8 * flashRegs)
Description:
This function verifies the CRC field of the User register store and then copies the contents
of this register store to the Operating register store in RAM.
Parameters:
flashRegs: A pointer to the User register store location in Flash.
Return Value:
uint8: status
Value
Side Effects:
Description
CYRET_SUCCESS
CRC matches and Operating register store was updated from
the User register store (Flash)
CYRET_BAD_PARAM
Invalid parameter value
CYRET_BAD_DATA
Data is bad. CRC doesn’t match
None
uint8 SMBusSlave_EraseUserAll(void)
Description:
This function erases the User register store in Flash. The API does not erase the Flash by
default. Instead it contains a call to the callback routinewhere the user can implement an
algorithm to erase the contents of the User register store in Flash.
Parameters:
None
Return Value:
uint8: status
Value
CYRET_SUCCESS
Description
Action completed successfully
Or other user-determined non-SUCCESS status
Side Effects:
None
Document Number: 002-03684 Rev. **
Page 21 of 47
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
uint8 SMBusSlave_RestoreDefaultAll(void)
Description:
This function verifies the signature field of the Default register store and then copies the
contents of the Default register store to the Operating register store in RAM.
Parameters:
None
Return Value:
uint8: One of following standard return statuses.
Value
Side Effects:
Description
CYRET_SUCCESS
Action completed successfully
CYRET_BAD_DATA
Data is bad. CRC does not match
None
uint8 SMBusSlave_StoreComponentAll(void)
Description:
This function updates the parameters of other components in the system with the current
PMBus settings. Because this action is very application specific, this function merely calls a
user provided callback function. The only component provided firmware is a return value
variable (retval) which is initialized to CYRET_SUCCESS and returned at the end of the
function. The rest of the function must be user provided.
Parameters:
None
Return Value:
uint8: One of following standard return statuses.
Value
CYRET_SUCCESS
Description
Action completed successfully
Or other user-determined non-SUCCESS status.
Side Effects:
None
uint8 SMBusSlave_RestoreComponentAll(void)
Description:
This function updates the PMBus Operating register store with the current configuration
parameters of other components in the system. Because this action is very application
specific, this function merely calls a user provided callback function. The only component
provided firmware is a return value variable (retval) which is initialized to
CYRET_SUCCESS and returned at the end of the function. The rest of the function must
be user provided.
Parameters:
None
Return Value:
uint8: One of following standard return statuses.
Value
CYRET_SUCCESS
Description
Action completed successfully
Or other user-determined non-SUCCESS status.
Side Effects:
Page 22 of 47
None
Document Number: 002-03684 Rev. **
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
float SMBusSlave_Lin11ToFloat (uint16 linear11)
Description:
This function converts the argument "linear11" to floating point and returns it.
Parameters:
uint16 linear11: A number in LINEAR11 format.
Return Value:
float: The linear11 parameter converted to floating point
Side Effects:
None
uint16 SMBusSlave_FloatToLin11 (float floatvar)
Description:
This function takes the argument "floatvar" (a floating point number) and converts it to a 16bit LINEAR11 value (11-bit mantissa + 5-bit exponent), which it returns.
Parameters:
float floatvar: A floating point number
Return Value:
uint16: floatvar converted to LINEAR11
Side Effects:
None
float SMBusSlave_Lin16ToFloat(uint16 linear16, int8 inExponent)
Description:
This function converts the argument "linear16" to floating point and returns it. The argument
Linear16 contains the mantissa. The argument inExponent is the 5-bit 2’s complement
exponent to use in the conversion.
Parameters:
uint16 linear16: The 16-bit mantissa of a LINEAR16 number.
int8inExponent: The 5-bit exponent of a LINEAR16 number. Packed in the lower 5 bits. 2’s
Complement.
Return Value:
float: The parameters converted to floating point
Side Effects:
None
uint16 SMBus_FloatToLin16(float floatvar, int8 outExponent)
Description:
This function takes the argument "floatvar" (a floating point number) and converts it to a 16bit LINEAR16 value (16-bit mantissa), which it returns. The argument outExponent is the 5bit 2’s complement exponent to use in the conversion.
Parameters:
floatfloatvar: A floating point number to be converted to LINEAR16.
int8outExponent: User provided 5-bit exponent to use in the conversion.
Return Value:
uint16: The parameters converted to LINEAR16.
Side Effects:
None
Document Number: 002-03684 Rev. **
Page 23 of 47
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
Global Variables
Function
SMBusSlave_initVar
Description
The initVar variable is used to indicate initial configuration of this component.
This variable is prepended with the component name, in this case, SMBusSlave.
The SMBusSlave_initVar variable is initialized to zero and set to 1 the first time
SMBusSlaveStart() is called. This allows for component initialization without
reinitialization in all subsequent calls to the SMBusSlave Start() routine.
If it is necessary to reinitialize the component, then the SMBusSlave_Init()
function can be called before the SMBusSlave_Start() or SMBusSlave_Enable()
function.
SMBusSlave_regs
Refer to Operating Register Store section of this document for a detailed
description.
SMBusSlave_regsDefault
Refer to Default Register Store section of this document for a detailed
description.
SMBusSlave_transactionData[]
Transaction queue structure. Refer to Transaction Queue section of this
document for a detailed description.
Bootloader Support
The SMBus and PMBus Slave component can be used as a communication component for the
Bootloader. For more information about the Bootloader, refer to the Bootloader component
datasheet.
Note In order to communicate with a PSoC device using the SMBus communication interface for
the Bootloader, an SMBus Bootloader Host is required. The Bootloader Host application
provided with PSoC Creator does not support SMBus protocol.
The component provides a set of API functions for Bootloader use.
Function
Description
SMBusSlave_CyBtldrCommStart
Starts the SMBus and PMBus Slave component and enables its interrupt.
SMBusSlave_CyBtldrCommStop
Disables the SMBus and PMBus Slave component and disables its
interrupt.
SMBusSlave_CyBtldrCommReset
Sets read and write I2C buffers to the initial state and resets the slave
status.
SMBusSlave_CyBtldrCommWrite
Allows the caller to write data to the bootloader host. This function
manages polling to allow a block of data to be completely sent to the host
device.
SMBusSlave_CyBtldrCommRead
Allows the caller to read data from the bootloader host. This function
manages polling to allow a block of data to be completely received from
the host device.
Page 24 of 47
Document Number: 002-03684 Rev. **
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
void SMBusSlave_CyBtldrCommStart(void)
Description:
Starts the communication component and enables the interrupt. The read buffer initial
state is full and the read always is 0xFFu. The write buffer is clear and ready to receive a
command.
Parameters:
None
Return Value:
None
Side Effects:
This function enables the component interrupt. If I2C is enabled without the interrupt
enabled, it could lock up the bus.
void SMBusSlave_CyBtldrCommStop(void)
Description:
Disables the communication component and disables the interrupt.
Parameters:
None
Return Value:
None
Side Effects:
None
void SMBusSlave_CyBtldrCommReset(void)
Description:
Sets buffers to the initial state and reset the statuses. The read buffer initial state is full and
the read always is 0xFFu. The write buffer is clear and ready to receive a command.
Parameters:
None
Return Value:
None
Side Effects:
None
Document Number: 002-03684 Rev. **
Page 25 of 47
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
cystatus SMBusSlave_CyBtldrCommRead(uint8 * pData, uint16 size, uint16 * count, uint8
timeOut)
Description:
Requests that the provided size number of bytes are read from the host device and stored
in the provided data buffer. Once the write is done count is updated with the number of
bytes written. The timeOut parameter is used to provide an upper bound on the time that
the function is allowed to operate. The host issues BOOTLOAD_WRITE command to
transfer the block of data to the PSoC device.
Parameters:
uint8 *pData: Pointer to storage for the block of data to be read from the bootloader host
uint16 size: Number of bytes to be read
uint16 *count: Pointer to the variable to write the number of bytes actually read
uint8 timeOut: Number of units in tens of milliseconds to wait before returning because of
a timeout
Return Value:
cystatus: Returns CYRET_SUCCESS if no problem was encountered or returns the value
that best describes the problem. For more information, see the "Return Codes" section of
the System Reference Guide.
Side Effects:
None
cystatus SMBusSlave_CyBtldrCommWrite(const uint8 * pData, uint16 size, uint16 * count,
uint8 timeOut)
Description:
Requests that the provided size number of bytes is written from the provided data buffer to
the host device. Once the write is done count is updated with the number of bytes written.
The timeOut parameter is used to provide an upper bound on the time that the function is
allowed to operate. The host issues BOOTLOAD_READ command to read the block of
data from the PSoC device.
Parameters:
const uint8 *pData: Pointer to the block of data to be written to the bootloader host
uint16 size: Number of bytes to be written
uint16 *count: Pointer to the variable to write the number of bytes actually written
uint8 timeOut: Number of units in tens of milliseconds to wait before returning because of
a timeout
Return Value:
cystatus: Returns CYRET_SUCCESS if no problem was encountered or returns the value
that best describes the problem. For more information see the "Return Codes" section of
the System Reference Guide.
Side Effects:
Temporarily disables the component interrupt when writing a block of data from the
bootloader to the component transfer buffer. The communication is not running during this
period of time
Macros
Macro
Description
SMBusSlave_FL_ADDR_TO_ROW(addr)
Extracts Flash row number from specified address
SMBusSlave_FL_ADDR_TO_ARRAYID(addr)
Extracts Flash array ID from specified address
Page 26 of 47
Document Number: 002-03684 Rev. **
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
Macro
Description
SMBusSlave_SIZE_TO_ROW(size)
Calculates and returns the number of Flash rows required to
store the number of data defined by size
SMBusSlave_MAX_PAGES
Specifies the maximum number of pages for paged commands
SMBusSlave_NUM_COMMANDS
Total number of supported commands
Sample Firmware Source Code
PSoC Creator provides numerous example projects that include schematics and example code
in the Find Example Project dialog. For component-specific examples, open the dialog from the
Component Catalog or an instance of the component in a schematic. For general examples,
open the dialog from the Start Page or File menu. As needed, use the Filter Options in the dialog
to narrow the list of projects available to select.
Refer to the "Find Example Project" topic in the PSoC Creator Help for more information.
MISRA Compliance
This section describes the MISRA-C:2004 compliance and deviations for the component. There
are two types of deviations defined:
project deviations – deviations that are applicable for all PSoC Creator components
specific deviations – deviations that are applicable only for this component
This section provides information on component-specific deviations. Project deviations are
described in the MISRA Compliance section of the System Reference Guide along with
information on the MISRA compliance verification environment.
The SMBus Slave component has the following specific deviations:
MISRAC:2004
Rule
11.4
Rule Class
(Required/
Advisory)
A
Rule Description
A cast should not be performed between
a pointer to object type and a different
pointer to object type.
Description of Deviation(s)
Violated for the following reasons:
To access a floating point variable as raw
32-bit value in FloatToLin11() and
FloatToLin16() unit conversion APIs
For byte access to/from 16-bit command
fields of the register store data structure.
For byte access to the register store
structure when the CRC field of the
register store is computed.
Document Number: 002-03684 Rev. **
Page 27 of 47
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
MISRAC:2004
Rule
Rule Class
(Required/
Advisory)
Rule Description
Description of Deviation(s)
11.5
R
A cast shall not be performed that
removes any const or volatile qualification
from the type addressed by a pointer.
A cast is performed when a pointer to
const is passed as the source buffer to
memcpy() c51 library routine which
expects void * type for this parameter.
17.4
R
Array indexing shall be the only allowed
form of pointer arithmetic.
The component applies array subscripting
to an object of pointer type to access
command fields of the register store
structure.
19.7
A
A function should be used in preference to Deviated for more efficient code.
a function-like macro.
This component has the following embedded components: Clock, I2C, Pin, TCPWM. Refer to the
corresponding component datasheets for information on their MISRA compliance and specific
deviations.
API Memory Usage
The component memory usage varies significantly depending on the compiler, device, number of
APIs used and component configuration.
Furthermore, the memory usage is dependent on the number of commands, the number of
pages, and the features enabled. Additional commands consume SRAM for the runtime register
store and Flash for the default register store and command lookup table. That is, the memory
usage is expressed as the size of base component code and the memory usage for additional
commands.
The following table provides the memory usage for all APIs available in the given component
configuration. The usage for each individual feature is presented as the additional memory space
required when the feature is enabled.
The measurements have been done with an associated compiler configured in Release mode
with optimization set for Size. For a specific design, the map file generated by the compiler can
be analyzed to determine the memory usage.
PSoC 3 (Keil_PK51)
Configuration
PSoC 4 (GCC)
PSoC 5LP (GCC)
Flash
SRAM
Flash
SRAM
Flash
SRAM
Bytes
Bytes
Bytes
Bytes
Bytes
Bytes
3340 +
CMDFLS
185 +
CMDRAM
2595 +
CMDFLS
195 +
CMDRAM
2400 +
CMDFLS
185 +
CMDRAM
SMBALERT# support
+102
+2
+140
+2
+110
+2
PEC support
+391
+1
+320
+1
+316
+1
Bootloader support
+376
+131
+326
+131
+318
+131
SMBus/PMBus core
Page 28 of 47
Document Number: 002-03684 Rev. **
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
N
CMDRAM REGS_SIZE cmd_sizei page_numi
i1
where:
REGS_SIZE is the size of the Register Store
N is the number of commands
cmd_size is the size of command in bytes
page_num is the number of pages for this command. For non-paged commands
page_num is 1.
Command size is dependent on the command type as follows:
Command type
Command size
Send Byte
0
Read/Write Byte
1
Read/Write Word, Process Call
2
Block Write/Read, Block Process Call
size from customizer + 1
CDMFLS REGS_SIZE CMD_LUT
where:
REGS_SIZE is the size of Register Store and is calculated as for SRAM usage
CMD_LUT is command lookup table size and is calculated as follows:
□
CMD_LUT = LUT_ENTRY * N
where:
LUT_ENTRY = 6 bytes for Keil_PK51 and 7 bytes for GCC 4.7.3
Document Number: 002-03684 Rev. **
Page 29 of 47
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
Functional Description
The theory of operation of this component is very similar to an I2C Slave component. All
references the SMBus specification refer to the SMBus specification version 2.0. Key
functionalities of the component are highlighted in this section.
I2C Physical Layer
The physical layer of the SMBus/PMBus slave component is based on the I2C protocol. The
three main differences that impact this component are:
The SMBus specification mandates that the component must reset and release the SCL and
SDA lines if the SCL signal is detected stuck low for 25 ms. This is described in more detail in
the DC and AC Electrical Characteristics section later in this document.
The SMBus Specification mandates that the component must not stretch the clock more than 25
ms (cumulative) in any given transfer. The slave is allowed to delay transfers when it is busy by
pulling SCL low (clock stretching) provided that the cumulative stretch time in any transaction
does not exceed 25 ms.
Addition of an SMBALERT# pin to notify the host that the device needs attention.
SMBus/PMBus Addressing
Every SMBus/PMBus slave device has an I2C address. The following addresses are reserved for
specific SMBus usage and must not be used as the generic slave address for an SMBus/PMBus
slave.
Slave Address (Bits 7:1)
R/W# bit (Bit 0)
Comment
0000 000
0
General Call Address
0000 000
1
START byte
0000 001
X
CBUS address
0000 010
X
Reserved for different bus format
0000 011
X
Reserved for future use
0000 1XX
X
Reserved for future use
0101 000
X
Reserved for ACCESS bus host
0110 111
X
Reserved for ACCESS bus default address
1111 0XX
X
Reserved for 10-bit slave addressing
1111 1XX
X
Reserved for future use
0001 000
X
Reserved for SMBus Host
0001 100
X
SMBus Alert Response Address
1100 001
X
SMBus Device Default Address
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PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
General Call Address
The general call address is for addressing every device connected to the bus. The component
responds to the General Call Address (00h) as well as its own physical address.
Note On PSoC 3 and PSoC 5LP, the Address decode parameter must be set to Software for the
component response to the General Call Address.
SMBus Alert Response Address
The component responds to its primary address and the SMBus Alert Response Address if the
SMBALERT# pin option is enabled.
SMBus Device Default Address
The SMBus Device Default Address is reserved for use by the SMBus Address Resolution
Protocol, which is not supported by the component.
SMBus/PMBus Protocols
Nine different protocols are defined in the SMBus Specification. A summary of these protocols
and their support statuses are shown below. Refer to section 5.5 “Bus Protocols” of the SMBus
specification for a detailed description of each protocol format.
Protocol
Support Status
Quick Command
Not Supported
Send Byte
Supported
Receive Byte
Supported (SMBus mode)
Write Byte/Word
Supported
Read Byte/Word
Supported
Process Call
Supported
Block Write/Read
Supported
Block Write/Block Read Process Call
Supported
SMBus Host Notify Protocol
Not Supported
The component also supports the Group Command Protocol as defined in PMBus Specification
Part I, section 5.2.3. The Group Command Protocol is used to send commands to multiple
devices in a single continuous transaction. It is not required that all devices receive the same
command. However, no more than one command can be sent to any one device in transaction.
The component executes the command received through the Group Command Protocol only
when the terminating STOP condition is detected.
The group command must only be used with write commands.
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Page 31 of 47
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
Key concepts that characterize the SMBus/PMBus component are as follows.
Neither the SMBus nor PMBus use the concept of a sub-address or an I2C register map. All
transfers are command based. Immediately following the slave device address is a command
code. Commands can be write-only, read-only or read/write. The SMBus specification does not
define any of the command codes and their read/write restrictions; they are up to the user to
define. However, the PMBus Specification Part II, Appendix I does define all 256 possible
command codes; 46 of these are up to the user to define (called manufacturer-specific
commands).
SMBus and PMBus are little-endian protocols (i.e., the least significant byte of a multi-byte datatype is transmitted first on the bus).
Register Stores Concept
According to the PMBus Specification II 5.4.2 – "Every Parameter That Can Be Written Must Be
Readable". In general, any command that accepts a value for writing must also return that value
when read. For this purpose, a concept of Register Stores is used.
Figure 1. Register Stores Concept
User Register Store
(Flash)
RESTORE_USER_ALL
SMBus_RestoreUserAll()
RESTORE_DEFAULT_ALL
SMBus_RestoreDefaultAll()
Default Register Store
(Flash)
SMBusSlave_Defaults.c
SMBus_RestoreComponenttAll()
STORE_USER_ALL
SMBus_StoreUserAll()
Operating Register
Store
(RAM)
SMBus_StoreComponenttAll()
Component Register
Store
(Component API’s)
SMBus/PMBus
Host
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PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
Operating Register Store
This is the RAM version of the register store. Runtime SMBus/PMBus commands modify this
version of the register store. Since this register store is located in RAM, its contents are assumed
to be invalid at reset.
Default Register Store
This is the Flash version of the register store, containing default values for all of the
SMBus/PMBus parameters. The parameter values in the Default register store are fixed at
compile/link time, but the user is responsible for providing the default values. Open the
SMBusSlave_Defaults.c file, copy the parameters from the comment block and paste them into
the cyapicallbacks.h or any header file included from cyapicallbacks.h. This will be store the
default values in SMBusSlave_regsDefault and the Operating register store will be initialized with
these parameters at every startup. The Operating register store can be initialized with default
values during component operation using SMBus_RestoreDefaultAll() API. This function can be
used in user handler for RESTORE_DEFAULT_ALL (0x12) PMBus command.
User Register Store
This is another Flash version of the register store. Unlike the Default register store, which is
essentially read-only, the User register store can be updated based on the current contents of
the Operating register store. Two API functions, SMBusSlave_StoreUserAll() and
SMBusSlave_RestoreUserAll(), are provided to work with this register store. These functions
perform CRC calculations that are used to check data validity at store/restore.
As storing data into Flash is very implementation specific, the default component does not
provide the code to storing anything into Flash. SMBusSlave_StoreUserAll() defines a callback
function to execute user-provided code that implements a method of storing data into Flash.
To design your own method of storing data into Flash, refer to the System Reference Guide.
Chapter 9 has basic information, various functions, and a set of macros for working with Flash.
Component Register Store
The primary motivation for the component register store is to allow PMBus to extract parameters
from and configure standard PSoC Creator components (thus, the name – Component register
store). Creator components have their own configuration parameters, which are usually set up
with the component customizer. These parameters are accessed at runtime via component
specific SMBusSlave_StoreComponentAll()/SMBusSlave_RestoreComponentAll() APIs. The
component parameters accessible via the API’s comprise the component register store. At
startup, user PMBus firmware may want to:
Update the other component settings based on PMBus parameters stored in User or
Default register stores, or
Update the PMBus Operating register store based on the component settings.
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Page 33 of 47
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
Transaction Queue
Any SMBus/PMBus commands not designated as AUTO must be handled in your main program
context in a timely manner. To accomplish this, the component will maintain a transaction queue
so your code may process bus transactions out of buried component ISR context.
Wherever the command of type “Manual” is detected, it is recorded in the Transaction Queue
and should be handled by user code. The Transaction Queue record has the following structure:
typedef struct
{
uint8 read;
uint8 commandCode;
uint8 page;
uint8 length;
uint8 payload[65];
} TRANSACTION_STRUCT
/*
/*
/*
/*
/*
r/w flag – 1=read 0=write */
SMBus/PMBus command code */
SMBus/PMBus page */
bytes transferred */
payload for the transaction */
The following are descriptions for the fields:
“read” is a flag that indicates the type of command received either Read or Write
“commandCode” is a 1-byte command code of the currently received command
“page” is a page number for the currently received command
It is only applicable for Paged commands. For Common commands this field is zero.
"length"
□
For the Write command, “length” specifies data length in bytes for the currently
received command.
□
For the Read command, “length” specifies the number of bytes to be sent.
□
For block commands, "length" includes the "byte count" byte.
"payload"
□
For Write commands, “payload” contains the received data for the current
command. User code is responsible for updating the Operating register store and
then calling SMBusSlave_CompleteTransaction().
□
For Read commands, "payload" isn't used. User code is responsible for updating
the variable for this command in the Operating register store and then calling
SMBusSlave_CompleteTransaction().
Each time a manual command is received, the component will stretch the clock until the pending
transaction is handled and SMBusSlave_CompleteTransaction() is called. For the Read
command, the clock stretching begins after repeated starts, waiting for the user code to provide
the response for the external host. For the Write command, the clock stretching begins after the
data for current command is received. When the clock stretching begins, the internal timer starts
to count the 25 ms timeout. If the SMBusSlave_CompleteTransaction() is not called before the
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PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
timeout occurrence, the component will reset the bus. The remaining record in the Transaction
Queue will be invalidated.
PAGE command
The PMBus PAGE (Code 0x00) command (PMBus Part II – Section 11.10) allows the access of
multiple logical PMBus devices at the same PMBus slave device address. For example, a
PMBus power supervisor that controls multiple power rails could provide access to the
commands/parameters for each rail on its own page. The component has built-in support for the
PAGE command. The page can be thought of as an index into an array of commands/registers.
Once the page is set via the PAGE command, the page setting is persistent until set again by
another PAGE command.
When Read/Write config for PAGE command is set to Auto (default), the component
automatically validates the command value. If the page setting exceeds the valid range, the
component will ignore the received PAGE command code. When the Read/Write config for
PAGE command is set to Manual, you have to provide the page value validation in your custom
command handler. The following code excerpt shows how to perform the bounds checking. The
example assumes the component instance name is "SMBusSlave."
/* PAGE should only be stored if it is not greater than MAX PAGES
* or equal to ALL PAGES.
*/
if((page < SMBusSlave_MAX_PAGES)||(page == SMBusSlave_CMD_ALL_PAGES))
{
SMBusSlave_regs.PAGE = page;
}
Valid PAGE command values are between 0 and the Max Page setting, determined by the user.
The exception is the "All Pages" wild card setting, which is 0xFF.
The "All Pages" wild card setting is only valid for write transactions, and must always be handled
in manual mode. If the PAGE is set to 0xFF, the following transactions are treated as errors:
An attempt to Read from a Paged command
An attempt to Write to a Paged command that is configured as Auto
Even in a PMBus device with multiple pages, some commands are not-dependent on the current
page and are always handled in the same way regardless of the PAGE setting. For example, the
PMBUS_REVISION command, which returns the PMBus version that the device supports, is
common to all pages. Thus, there is a concept of Page commands and Common commands. For
each SMBus/PMBus command, the customizer allows the user to specify whether the command
is Paged or Common. When a command is marked as Paged, the component defines an array in
the Register Store for that command.
Bootloader Commands
When the component is placed in a "Bootloader" project, two additional commands become
available in the Configure dialog on the Custom Commands tab. These commands are
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SMBus and PMBus Slave
PSoC® Creator™ Component Datasheet
BOOTLOAD_READ and BOOTLOAD_WRITE with default command codes of 0xFD and 0xFC,
respectively. They add a capability to the component to act as a communication component for
the Bootloader component.
These two commands interact with the bootloader component placed on a design schematic.
After placing the bootloader component, select "Custom interface" in the bootloader component
Configure dialog.
Note The bootloader commands use Block write/read bus protocol as defined in the SMBus
specification. According to the specification, a Block Read or Write is allowed to transfer a
maximum of 32 data bytes, when the component allows transferring a maximum of 64 data bytes
in one bootloader command. This does not prevent the component operation with legacy SMBus
host devices and adds more flexibility to a design. In general any packet length of up to 64 bytes
is supported for the bootloader commands. 64 bytes does not include a byte count for data bytes
transferred in a packet.
Data Transmission and Content Faults
The component responds to the transmission and content faults defined in the PMBus
Specification in a deterministic manner and after that calls the HandleBusError() function to notify
the user firmware. This would give user firmware an opportunity to set the appropriate error bit in
the STATUS_CML register. The following bus errors are reported by the component:
Corrupted Data
Corrupted data can only be detected if Packet Error Checking (PEC) is enabled in the
customizer (Disabled by default). Whenever the component detects that the received and
calculated PEC bytes do not match, it will respond as follows:
NACK the PEC byte
Not respond to or act upon the received command
Ignore the received command code and any received data
Call HandleBusError(ERR_CORRUPTED_DATA) to notify the user firmware
Host Sends or Reads Too Few Bytes
For each supported command, the component expects a fixed number of bytes to be written. If
the host transmits fewer bytes than expected, the component completely ignores the command
and takes no action.
Host Sends Too Many Bytes
For each supported command, the component expects a fixed number of bytes to be written. If
the host sends more bytes than expected, this is a data transmission fault.
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PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
Sending a PEC byte to the component if the Packet error checking is disabled is included in this
fault.
When the component detects this fault, it will respond as follows:
NACK all of the unexpected bytes as they are received (until the next STOP condition is
received)
Ignore the received command code and any received data
Call HandleBusError(ERR_WR_TOO_MANY_BYTES) to notify the user firmware
Reading Too Many Bytes
For each supported command, the component expects a fixed number of bytes to be read. If
while reading from the component, the host tries to read more bytes than the component is
expecting to send, this is a data transmission fault.
Trying to read a PEC byte if the Packet error checking is disabled is included in this fault.
When the component detects this fault, it will respond as follows:
Send all ones (FFh) as long as the host keeps clocking and acknowledging
Call HandleBusError(ERR_RD_TOO_MANY_BYTES) to notify the user firmware
Improperly Set Read Bit in the Address Byte
This error occurs when the Read bit is set on the first Address after the START. This is illegal for
PMBus since all transactions begin with a Write. However, if the component is in SMBus mode,
this is a valid “Receive Byte” protocol transaction. When the component detects this fault, it will
respond as follows:
ACK the address byte as all SMBus devices must ACK their own address
Send all ones (FFh) as long as the host keeps clocking and acknowledging
Call HandleBusError(ERR_READ_FLAG) to notify the user firmware
Unsupported Command Code
If the component receives a command that it does not support, it will respond as follows:
NACK the unsupported command code and all data bytes received before the next STOP
condition
Ignore the received command code and any received data
Call HandleBusError(ERR_UNSUPPORTED_CMD) to notify the user firmware
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SMBus and PMBus Slave
PSoC® Creator™ Component Datasheet
Host Reads from a Write Only Command
When the host tries to read from a write only command, this is a data content fault. The
component will respond as follows:
Send all ones (FFh) as long as the host keeps clocking and acknowledging
Call HandleBusError(ERR_INVALID_DATA) to notify the user firmware
Host Writes to a Read Only Command
When the host tries to write to a read only command, this is a data content fault. The component
will respond as follows:
Ignore the received command code and any received data
Call HandleBusError(ERR_INVALID_DATA) to notify the user firmware
Host Reads from a Paged Command if the PAGE is 0xFF
An attempt to read from a paged command if the page is set to “All pages” wildcard (0xFF) is a
data content fault. The component will respond as follows:
Send all ones (FFh) as long as the host keeps clocking and acknowledging
Call HandleBusError(ERR_INVALID_DATA) to notify the user firmware
Host Writes to a Paged Command if the PAGE is 0xFF
An attempt to write to a paged command if the page is set to “All pages” wildcard (0xFF) is
considered as a data content fault if the command is configured for Auto Write mode. The
component will respond as follows:
Ignore the received command code and any received data
Call HandleBusError(ERR_INVALID_DATA) to notify the user firmware
SMBus Timeout
When the component detects any single clock held low longer than the timeout period
(tTIMEOUT = 25 ms), the component resets its communication and releases the bus. The
component notifies the user firmware by calling HandleBusError(ERR_INVALID_DATA) API prior
re-enabling its communication interface.
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Document Number: 002-03684 Rev. **
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
User Provided Code Sections
Several component functions should take very application-specific actions, for example:
storing/restoring the content of the Operating register store to/from the User register store
in Flash
providing the initial values for the Default register store parameters
setting the appropriate error bit in the STATUS_CML register as response to data
transmission and content faults
additional actions during a data transmission in the component ISR
Therefore these functions must be user-provided. To accomplish this goal, the API files that are
automatically generated by PSoC Creator provide the concept of callback functions to execute
the custom code. Refer to the PSoC Creator Help and Component Author Guide for the more
details.
In order to add code to the macro callback present in the component’s generated source files,
perform the following:
Define a macro to signal the presence of a callback (in cyapicallbacks.h). This will
“uncomment” the function call from the component’s source code.
Write the function/macro declaration (in cyapicallbacks.h). This will make this function
visible by all the project files.
Write the function implementation (in any user file).
All of these callbacks can be found in the SMBusSlave.c, SMBusSlave_Defaults.c, and
SMBusSlave_INT.c API source code files, located in the Generated_Source/<Device> [1]/
SMBusSlave folder in the Workspace Explorer window. Note that the file name and folder
name examples assume that the instance name of the component is set to SMBusSlave.
The following are summaries of files with the callbacks.
SMBusSlave.c
Function
SMBusSlave_HandleSmbAlertResponse()
1.
User code purpose
The aftermath of a component response to the Alert Response
Address. For example, update of the STATUS_CML register and deassert the SMBALERT# pin.
These are shown as “PSoC3”, “PSoC4”, or “PSoC5” depending on the device family targeted.
Document Number: 002-03684 Rev. **
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SMBus and PMBus Slave
PSoC® Creator™ Component Datasheet
Function
User code purpose
SMBusSlave_GetReceiveByteResponse()
Providing a data byte to respond to a "Receive Byte" protocol request.
SMBusSlave_HandleBusError()
The aftermath of a data transmission and content fault, e.g. setting an
error bit in the STATUS_CML register for a PMBus device.
SMBusSlave_StoreUserAll()
Storing the Operating register store to the User register store in Flash.
SMBusSlave_EraseUserAll()
Erasing the User register store in Flash.
SMBusSlave_StoreComponentAll()
Updating the parameters of other components in the system
according to the content of the Operating register store.
SMBusSlave_RestoreComponentAll()
Updating the content of the Operating register store according to the
parameters of other components in the system.
To design your own method of storing data into Flash, refer to the System Reference Guide.
Chapter 9 has basic information and descriptions of functions that work with Flash.
SMBusSlave_Defaults.c
There is a macro for providing the initial parameter values in the Default register store that are
fixed at compile/link time. Refer to Default Register Store section for details.
SMBusSlave_INT.c
As with the SMBusSlave.c file, there are three callbacks in the interrupt service routine. One
section is just after interrupt entry, another where the received address and the device address
match and the last is situated just before exit from the interrupt service routine.
References
System Management Bus (SMBus) Specification (Version 2.0)
PMBusTM Power System Management Protocol Specification Part I – General
Requirements, Transport and Electrical Interface (Revision 1.2)
PMBusTM Power System Management Protocol Specification Part II – Command
Language (Revision 1.2)
Page 40 of 47
Document Number: 002-03684 Rev. **
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
Resources
On PSoC 3 and PSoC 5LP, the SMBus/PMBus component resource usage is mostly dependent
on the implementation type of the I2C interface. That is, the I2C can either be implemented in the
UDB array or use the dedicated I2C Fixed Function (FF) block. On PSoC 3 and PSoC 5LP the
component utilizes the following resources.
Resource Type
Configuration
Datapath
Cells
Macrocells
Status
Cells
Control
Cells
I2C Fixed
Blocks
Interrupts
SMBus / PMBus (UDB)
2
29
3
4
-
2
SMBus / PMBus (FF)
1
5
1
2
1
2
On PSoC 4 there are no options for the implementation type of the I2C interface. The component
utilizes a Serial Communication Block (SCB), a Timer/Counter/PWM Block (TCPWM) and two
Interrupts.
DC and AC Electrical Characteristics
Specifications are valid for –40 °C ≤ TA ≤ 85 °C and TJ ≤ 100 °C, except where noted.
Specifications are valid for 1.71 V to 5.5 V, except where noted.
Note The data for the PSoC 4200L device is preliminary. Final data will be delivered in an
upcoming Component Pack.
DC Characteristics
Parameter
Description
Min
Typ
Max
Unit
1.71
–
5.5
V
VDD
Nominal bus voltage [2]
VIH
Input high voltage (CMOS Input)
0.7 x VDD
–
–
V
VIL
Input low voltage (CMOS Input)
–
–
0.3 x VDD
V
VIH
Input high voltage (LVTTL Input, VDD < 2.7 V)
0.7 x VDD
–
–
V
VIH
Input high voltage (LVTTL Input, VDD ≥ 2.7 V)
2.0
–
–
V
VIL
Input low voltage (LVTTL Input, VDD < 2.7 V)
–
–
0.3 x VDD
V
VIL
Input low voltage (LVTTL Input, VDD ≥ 2.7 V)
–
–
0.8
V
VOL
Output low voltage
(IOL = 8 mA at 3 V VDD)
–
–
0.6
V
(IOL = 3 mA at 3 V VDD)
–
–
0.4
V
2.
VDD is listed as VDDIO for PSoC 3 / PSoC 5LP and VDDD for PSoC 4.
Document Number: 002-03684 Rev. **
Page 41 of 47
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
Parameter
Description
Min
Typ
Max
Unit
ILEAK-PIN
Input Leakage per device pin
–
–
2
nA
IPULLUP
Current sinking
(VOL = 0.6V at 3 V VDD)
8
–
–
mA
(VOL = 0.4V at 3 V VDD)
3
–
–
mA
–
–
7
pF
FF I2C at 100 kHz
–
620
–
μA
FF I2C at 400 kHz
–
860
–
μA
UDB I2C at 100 kHz
–
440
–
μA
UDB I2C at 400 kHz
–
720
–
μA
SCB I2C at 100 kHz
–
100
–
μA
SCB I2C at 400 kHz
–
300
–
μA
Ci
Input Capacitance
IDD [3]
Component current consumption
PSoC 3/5LP
PSoC 4
AC Characteristics
Parameter
Description
Min
Typ
Max
Unit
SMBus Mode
fSMB
SMBus operating frequency
10
–
100
kHz
tBUF
Bus free time between a stop and start condition
4.7
–
–
μs
tHD_STA
Hold time after a (Repeated) start condition
4.0
–
−
μs
tSU_STA
Setup time for a repeated start condition
4.7
–
−
μs
tSU_STO
Setup time for stop condition
4.0
–
−
μs
tHD_DAT
Data hold time
300
–
−
ns
tSU_DAT
Data setup time
250
–
−
ns
tLOW
Low period of the SCL clock
4.7
–
−
μs
tHIGH
High period of the SCL clock
4.0
–
−
μs
fPMB
PMBus operating frequency
100
–
400
kHz
tBUF
Bus free time between a stop and start condition
1.3
–
–
μs
tHD_STA
Hold time after a (Repeated) start condition
0.6
–
−
μs
PMBus Mode
3.
Device IO and clock distribution current are not included. The values are at 25 °C. Data was measured at
BUS_CLK set to 24 MHz
Page 42 of 47
Document Number: 002-03684 Rev. **
PSoC® Creator™ Component Datasheet
Parameter
SMBus and PMBus Slave
Description
Min
Typ
Max
Unit
tSU_STA
Setup time for a repeated start condition
0.6
–
−
μs
tSU_STO
Setup time for stop condition
0.6
–
−
μs
tHD_DAT
Data hold time
300
–
−
ns
tSU_DAT
Data setup time
100
–
−
ns
tLOW
Low period of the SCL clock
1.3
–
−
μs
tHIGH
High period of the SCL clock
0.6
–
−
μs
−
16 × data rate
−
kHz
Common Parameters
fCLOCK
Component input clock frequency
PSoC 3 / 5LP
All data rates
PSoC 4
Data rate ≤ 100 kbps
1.55
−
12.8
MHz
Data rate = 400 kbps
7.82
−
15.38
MHz
tTIMEOUT
Detect clock low timeout
25
–
35
ms
tLOW_SEXT
Cumulative clock low extend time
–
−
25
ms
tF
Clock/Data Fall Time (3.3V VDDIO CLOAD = 25 pF)
–
−
12
ns
tR
Clock/Data Rise Time (3.3V VDDIO CLOAD = 25 pF)
–
−
12
ns
tPOR [4]
Time in which a device must be operational after
power-on reset
–
−
200
μs
tRESET
Reset pulse width
−
2
−
1/fCLOCK
Figure 2. Data Transition Timing Diagram
SDA
tf
tLOW
tr
tSU;DAT
tf
tHD;STA
tr
tBUF
SCL
tHD;STA tHD;DAT
S
4.
tHIGH
tSU;STA
tSU;STO
SR
P
S
Based on device characterization (Not production tested). The measurement was done with the sole
SMBusSlave component in a design and includes the time from VDDD/VDDA/VCCD/VCCA ≥ PRES to the
component is in operational state (no PLL used, slow IMO boot mode at 12 MHz).
Document Number: 002-03684 Rev. **
Page 43 of 47
SMBus and PMBus Slave
PSoC® Creator™ Component Datasheet
Component Changes
This section lists the major changes in the component from the previous version.
Version
5.10
5.0.a
5.0
4.0
Description of Changes
Reason for Changes / Impact
Added PSoC 4200L device support.
New device support.
Consolidated current consumption numbers for
PSoC 4 in the DC Characteristics section.
The numbers are same across most PSoC 4
families.
Updated User Provided Code Sections with
information on macro callbacks.
Added support for the macros callbacks.
Enabled component to be nested into other
components.
Support for hierarchical component design.
Updated versions of the embedded
components to the most current version.
Keeping the embedded component versions up to
date.
Corrected a defect with SCL timeout detection
when the fixed function I2C is selected.
SCL timeout was not detected when the fixed
function I2C implementation was selected on the I2C
Configuration Tab for PSoC 3 / PSoC 5LP devices.
Corrected a defect when all subsequent reads
from a paged command failed after a write to a
paged command with a page set to all pages
(0xFFh).
When a page was set to all pages (0xFF), a write
transaction to a paged command caused component
to fail on all subsequent reads from a paged
command.
The component sends FFh when the host tries
to read an unsupported command.
Improved error detection and reporting.
Edited the datasheet.
Updated DC and AC Electrical Characteristics
section with PSoC 4100M/PSoC 4200M data.
Added support for Bluetooth Low Energy
devices.
New device support.
Changed clock requirements for PSoC 4
component version.
PSoC 4 implementation of the SMBus and PMBus
Slave component v4.0 is built on top of the SCB I2C
Slave v2.0. Thus it inherited functional changes of
Removed Oversampling factor and Median filter this SCB I2C version. Refer to the SCB I2C Slave
options from I2C Configuration Tab on
v2.0 datasheet for more information.
PSoC 4.
3.0
Added Manual Read/Write support for PAGE
command.
Enables custom page value processing in user’s
command handler. Auto Read/Write configs are not
affected.
Datasheet update and corrections.
To reflect all changes in version 4.0.
Added PSoC 4000 / PSoC 4100 / PSoC 4200
family support.
New device support.
Added Packed error checking support.
Improved reliability and communication robustness.
Code optimization and refactoring.
Improved code efficiency and reduced memory
footprint.
Page 44 of 47
Document Number: 002-03684 Rev. **
PSoC® Creator™ Component Datasheet
Version
2.20
Description of Changes
SMBus and PMBus Slave
Reason for Changes / Impact
Corrected a defect with processing of unpaged
commands when a page was set to all pages
(0xFF).
Component ignored the received command code and
any received data for unpaged commands when a
page was set to all pages (0xFF).
Corrected a defect with Process Call protocol
commands.
Component ignored the received data and incorrectly
generated Reading Too Many Byte fault condition for
this type of transactions. Problem solved.
Improved the mechanism of responses to data
transmission faults.
Improved the efficiency of responses to data
transmission faults.
Corrected a defect with incomplete block write
commands that may cause data corruption in
the register store.
For each supported command, the component
expects a fixed number of bytes to be written. If the
host transmits fewer bytes than expected, the
component completely ignores the command and
takes no action.
Added detection of Reading Too Many Bytes
fault for Receive Byte protocol.
Improved error detection and reporting.
Added detection of Reading Too Many Bytes
fault for Receive Byte protocol.
Improved error detection and reporting.
Corrected the number of bytes expected for
SMBALERT_MASK command to comply with
PMBus specification.
The number of bytes for SMBALERT_MASK did not
correspond to the command size specified in PMBus
specification.
Corrected a defect with de-assertion of
SMBALERT# pin in Auto mode.
SMBALERT# pin did not automatically de-assert
after the host queried the device at the Alert
Response Address.
Added support of the General Call address
(00h).
The component may respond to the General Call
address (00h) as well as its own physical address.
Added Manufacturer value to the command
Format parameter in the Configure dialog
Allows selection of the manufacturer-specific data
format value for a command.
Datasheet update and corrections.
To reflect all changes in version 3.0.
The issue that caused the component to
The issue was caused by incorrect condition of
transmit "junk" data (instead of FFs) while trying handling read part of a command inside component
to read write-only command was fixed.
ISR.
Support of PSoC 5 family devices was removed
from the component.
API Memory Usage table was updated with new
values.
The description of Transaction Queue was
added.
Information about the Transaction Queue is required
for handling of the Manual type commands.
Fixed the issue related to erroneous setting the
page number to maximum page number value.
Maximum page number should be maximum page
number value minus one as the page indexing starts
with zero.
Document Number: 002-03684 Rev. **
Page 45 of 47
SMBus and PMBus Slave
Version
Description of Changes
Erroneous presence of clock input was fixed.
PSoC® Creator™ Component Datasheet
Reason for Changes / Impact
When the Fixed Function implementation of I2C was
selected in the component customizer the
component must not expose the clock input on the
symbol as it can only use internal clock in this mode.
The label "Actual data rate" on the General tab
of the customizer was changed to "Attainable
data rate".
2.10
The issue related to inability of changing the
PAGE to 0xFF (“all pages” wildcard) was fixed.
2.0
The PMBus Register store was made to be
always declared using arrays for paged
commands even when the user selects only 1
page in the design.
This was an error that might lead to code
restructuring.
Added "Pages" column to the Custom
Commands table.
This is a new parameter that defines the page
number for specific custom command.
Fixed issue with incomplete block writes
transactions.
The code was changed to verify if the number of
bytes specified by "Byte count" field equals to
number of received data bytes. Previously code
verified if number of data equals to the "Size"
parameter for specific block command that is entered
by user in the component customizer.
Removed compilation error that is occurred in
case when SMBALERT pin was left
unconnected.
Fixed issue which caused erroneous generation
of bus error in while processing of page
indexed, manual command when page was set
to "all pages" wildcard.
Restricted slave address from using addresses
reserved for specific SMBus usage.
Component did not validate the address.
Fixed minor issues.
The new function was added SMBusSlave_EraseUserAll().
1.10
Added MISRA Compliance section.
The component was not verified for MISRA
compliance.
Updated SMBus and PMBus Slave with the
latest version of the I2C and Control Register
components.
1.0
First release
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Document Number: 002-03684 Rev. **
PSoC® Creator™ Component Datasheet
SMBus and PMBus Slave
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Document Number: 002-03684 Rev. **
Page 47 of 47