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Question from the Customer:

I would like to use the Aardvark I2C/SPI Adapter in SPI mode and the Aardvark Software API to communicate with SDC and MMC cards. I need to verify that files were successfully programmed in the production environment. Can I search for files on an SDC Card using the Aardvark I2C/SPI Host Adapter?

Response from Technical Support:

Thanks for your question! You can search for and verify files on SDC or MMC cards, but first you must set up the SDC or MMC cards in SPI mode. For this process, we recommend using the Promira Serial Platform and Promira Software API I2C/SPI Active. This setup requires setting up the sequence using low-level bit level programming. You can do this sequencing with the Promira platform, which can be configured to communicate with various bit-size bytes (2-32 bits), a feature that the Aardvark adapter does not support.

Accessing SDC and MMC Cards in SPI Mode

Here is an overview about communicating with the SDC/MMC cards via SPI:

• SDC/MMC cards can be accessed using an SPI bus, as the physical pins are similar.
• Before the cards can be accessed using the SPI bus, they must to be put in SPI mode. Putting a card in SPI mode requires a specific power-up sequence.

ELM-ChaN published an article that describes the process to set up SDC and MMC cards in SPI Mode, which is performed during the initialization sequence.

The Required Power-Up Sequence for SPI Modes

Here is a summary of the power-up sequence:

1. Power ON
2. Wait 1 ms
3. Send at least 74 clock pulses on the clock pin while CS and DI are high. After this step, the card will be in SPI mode.

The following diagram shows the details of this operation:

 

Source: ELM-ChaN

Advantages of Using the Promira Serial Platform

As previously mentioned, the Aardvark adapter does not support the required initialization sequence, as it only supports 8 bit words.  We recommend the Promira Serial Platform because it supports variable bit-length. There are multiple SPI Active applications available for the Promira platform.  The  SPI Active - Level 1 Application fulfills the requirements that you specified. Here is a summary of the features of the three levels of SPI Active applications:

• SPI Active - Level 1 Application supports active communication on the bus, including high speed programming up to 12.5 MHz for Master and 8 MHz for Slave.
• SPI Active - Level 2 Application supports active communication on the bus, including high speed programming up to 40 MHz for Master and 20 MHz for Slave. Dual SPI is supported.
• SPI Active - Level 3 Application and active communication on the bus, including high speed programming up to 80 MHz for Master and 20 MHz for Slave. Dual and Quad SPI are also supported.

NOTE:  using the SPI Active - Level 2 and Level 3 Applications require the installation of the previous Active levels.

The Promira platform also has built-in features, such as level shifting, more power to deliver to target devices, Ethernet connectivity and more. For a complete list of features, please refer to the Promira Serial Platform data sheet.

Additional resources that you may find helpful include the following:

• Promira Serial Platform I2C/SPI Active User Manual
• Promira Serial Platform Quick Start Guide
• Aardvark I2C/SPI Host Adapter User Manual

We hope this answers your question. Looking for more information? You can ask us at sales@totalphase.com. You can also request a demo that applies to your application.

Request a Demo