Microsemi SmartFusion2 MSS CAN Configuration User Guide

SmartFusion2 MSS
CAN Configuration

Introduction

The SmartFusion2 Microcontroller Subsystem (MSS) provides one CAN hard peripheral (APB_1 sub bus).
On the MSS Canvas, you must enable (default) or disable the CAN instance based on whether it is being used in your current application. When disabled, the CAN instance is held in reset (lowest power state).
By default, when enabled, the CAN ports are configured to connect to the device Multi Standard I/Os (MSIOs). Note that MSIOs allocated to the CAN instance are shared with other MSS peripherals. These shared I/Os are available to connect to MSS GPIOs and other peripherals when the CAN instance is disabled or if the CAN instance ports are connected to the FPGA fabric.
The functional behavior of the CAN instance must be defined at the application level using the SmartFusion2 MSS CAN Driver provided by Microsemi.
In this document, we describe how you can configure the MSS CAN instance and define how the peripheral signals are connected.
For more details about the MSS CAN hard peripheral, please refer to the SmartFusion2 User Guide.

Configuration Options

There are no hardware configuration options for the CAN peripheral.
Note: If the CAN instance is enabled, M3_CLK must be a multiple of 8MHz. This restriction will be enforced in the MSS CCC Configurator.

Peripheral Signals Assignment Table

The SmartFusion2 architecture provides a very flexible schema for connecting peripherals signals to either MSIOs or the FPGA fabric. Use the signal assignment configuration table to define what your peripheral is connected to in your application. This assignment table has the following columns (Figure 2-1):
MSIO – Identifies the peripheral signal name configured in a given row.
Main Connection – Use the drop-down list to select whether the signal is connected to an MSIO or the FPGA fabric.
Direction – Indicates if the signal direction is IN, OUT or INOUT.
Package Pin – Shows the package pin associated with the MSIO when the signal is connected to an MSIO.
Extra Connections – Use the Advanced Options check-box to view the extra connection options:

• Check the Fabric option to observe into the FPGA fabric a signal that is connected to an MSIO.
• Check the GPIO option to observe an input direction signal – from either the FPGA fabric or an MSIO – using an MSS GPIO.

Connectivity Preview

The Connectivity Preview panel in the MSS CAN Configurator dialog shows a graphical view of the current connections for the highlighted signal row (Figure 3-1).

Resource Conflicts

Because MSS peripherals (MMUART, I2C, SPI, CAN, GPIO, USB, Ethernet MAC) share MSIO and FPGA fabric access resources, the configuration of any of these peripherals may result in a resource conflict when you configure an instance of the current peripheral. Peripheral configurators provide clear indicators when such a conflict arises.
Resources used by a previously configured peripheral result in three types of feedback in the current peripheral configurator:
• Information – If a resource used by another peripheral does not conflict with the current configuration, an information icon appears in the connectivity preview panel, on that resource. A tooltip on the icon provides details about which peripheral uses that resource.
• Warning/Error – If a resource used by another peripheral conflicts with the current configuration, a warning or error icon appears in the connectivity preview panel, on that resource. A tooltip on the icon provides details about which peripheral uses that resource.
When errors are displayed you will not be able to commit the current configuration. You can either resolve the conflict by using a different configuration or cancel the current configuration using the Cancel button.
When warnings are displayed (and there are no errors), you can commit the current configuration. However, you cannot generate the overall MSS; you will see generation errors in the Libero SoC log window. You must resolve the conflict that you created when you committed the configuration by reconfiguring either of the peripherals causing the conflict.
The peripheral configurators implement the following rules to determine if a conflict should be reported as an error or a warning.

1. If the peripheral being configured is the GPIO peripheral then all conflicts are errors.
2. If the peripheral being configured is not the GPIO peripheral then all conflicts are errors unless the conflict is with a GPIO resource in which case conflicts will be treated as warnings.

Error Example
The USB peripheral is used and uses the device PAD bounded to package pin V24. Configuring the CAN peripheral such that the RXBUS port is connected to an MSIO results in an error.
Figure 4-1 shows the error icon displayed in the Connectivity Assignment table for the RXBUS port. Figure 4-2 shows the error icon displayed in the Preview panel on the PAD resource for the RXBUS port.
Warning Example
The GPIO peripheral is used and uses the device PAD bounded to package pin V24 (GPIO_3).
Configuring the CAN peripheral such that the RXBUS port is connected to an MSIO results in a warning.
Figure 4-3 shows the warning icon displayed in the Connectivity Assignment table for the RXBUS port.
Figure 4-4 shows the warning icon displayed in the preview panel on the PAD resource for the RXBUS port. Note that in this example, there is a second conflict with a GPIO because of the extra connection to GPIO_3.
Information Example
The USB peripheral is used and uses the device PAD bounded to package pin V24. Configuring the CAN peripheral such that the RXBUS port is connected to the FPGA fabric does not result in a conflict. However, to indicate that he PAD associated with the RXBUS port (but not used in this case), the Information icon is displayed in the Preview panel (Figure 4-5). A tooltip associated with the icon provides a description of how the resource is used (USB in this case).

Port Description

Table 5-1 • Port Description

external CAN transceiver. / TX_EN_N is asserted when the CAN controller is stopped or if the CAN state is bus-off.

Note:

• Port names have the name of the CAN instance as a prefix, e.g. CAN_RX.
• Fabric main connection input ports names have “F2M” as a suffix, e.g. CAN _RX_F2M.
• Fabric extra connection input ports names have “I2F” as a suffix, e.g. CAN_RX_I2F.
• Fabric output and output-enable ports names have “M2F” and “M2F_OE” as a suffix, e.g. CAN_RXM2F and CAN RX_M2F_OE.
• PAD ports are automatically promoted to top throughout the design hierarchy.

Product Support

Microsemi SoC Products Group backs its products with various support services, including Customer Service, Customer Technical Support Center, a website, electronic mail, and worldwide sales offices. This appendix contains information about contacting Microsemi SoC Products Group and using these support services.
Customer Service
Contact Customer Service for non-technical product support, such as product pricing, product upgrades, update information, order status, and authorization.
From North America, call 800.262.1060
From the rest of the world, call 650.318.4460
Fax, from anywhere in the world, 408.643.6913
Customer Technical Support Center
Microsemi SoC Products Group staffs its Customer Technical Support Center with highly skilled engineers who can help answer your hardware, software, and design questions about Microsemi SoC Products. The Customer Technical Support Center spends a great deal of time creating application notes, answers to common design cycle questions, documentation of known issues, and various FAQs. So, before you contact us, please visit our online resources. It is very likely we have already answered your questions.
Technical Support
Visit the Customer Support website (www.microsemi.com/soc/support/search/default.aspx) for more information and support. Many answers available on the searchable web resource include diagrams, illustrations, and links to other resources on the website.
Website
You can browse a variety of technical and non-technical information on the SoC home page, at www.microsemi.com/soc.
Contacting the Customer Technical Support Center
Highly skilled engineers staff the Technical Support Center. The Technical Support Center can be contacted by email or through the Microsemi SoC Products Group website.
Email
You can communicate your technical questions to our email address and receive answers back by email, fax, or phone. Also, if you have design problems, you can email your design files to receive assistance. We constantly monitor the email account throughout the day. When sending your request to us, please be sure to include your full name, company name, and your contact information for efficient processing of your request.
The technical support email address is soc_tech@microsemi.com.
My Cases
Microsemi SoC Products Group customers may submit and track technical cases online by going to My Cases.
Outside the U.S.
Customers needing assistance outside the US time zones can either contact technical support via email (soc_tech@microsemi.com) or contact a local sales office. Sales office listings can be found at www.microsemi.com/soc/company/contact/default.aspx.
ITAR Technical Support
For technical support on RH and RT FPGAs that are regulated by International Traffic in Arms Regulations (ITAR), contact us via soc_tech_itar@microsemi.com. Alternatively, within My Cases, select Yes in the ITAR drop-down list. For a complete list of ITAR-regulated Microsemi FPGAs, visit the ITAR web page.
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References

• Microsemi | Semiconductor & System Solutions | Power Matters
• Libero® SoC Design Suite Versions 2023.2 to 12.0 | Microchip Technology
• Libero® SoC Design Suite Versions 2023.2 to 12.0 | Microchip Technology
• Libero® SoC Design Suite Versions 2023.2 to 12.0 | Microchip Technology
• Libero® SoC Design Suite Versions 2023.2 to 12.0 | Microchip Technology
• Libero® SoC Design Suite Versions 2023.2 to 12.0 | Microchip Technology
• Libero® SoC Design Suite Versions 2023.2 to 12.0 | Microchip Technology

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