Question from the Customer:
I have both the Aardvark I2C/SPI Host Adapter and the Beagle I2C/SPI Protocol Analyzer. In addition to monitoring, I am trying to perform 16-bit read and write operations over SPI. The Aardvark I2C/SPI Host Adapter User Manual states that you can send two 8-bits sequences as an SPI Master, and requires a setup time, td, between the 8-bit data sets. It also requires the td setup as an SPI Slave.
Response from Technical Support:Thanks for your question! The Aardvark adapter is a general purpose device that actively communicates on the bus, and provides master and slave capability along with I2C/SPI features. The Aardvark supports SPI master at up to 8 MHz, and SPI slave up to 4 MHz. As you noted, the Aardvark adapter SPI does have setup td (as a master, 7 to 9 us; as a slave minimum, 4 us) between two bytes of 8 bits. There are no options to configure the Aardvark adapter without those delays.
For your system requirements, Total Phase offers two products that support 16-bit SPI transactions with little or no setup delays: the Cheetah SPI Host Adapter and the Promira™ Serial Platform.
Figure 1: Cheetah SPI Host AdapterAs an SPI Master, the Cheetah SPI Host Adapter actively communicates on the bus, operates at high speeds up to 50 MHz, can provide gapless shifting, and provides control over the timing of the data that is shifted out. The Cheetah adapter can run 16-bit data transactions without delay. For information about the SPI signal timing, please refer to section 2.5 of the Cheetah SPI Host Adapter User Manual.
Figure 2: Promira Serial PlatformFor both SPI Slave and SPI Master modes, we recommend the Promira Serial Platform. Currently, the Promira platform supports the I2C Active - Level 1and the SPI Active-Level 1 Applications. I2C/SPI Active - Level 1 The SPI application supports the following:
- Active communication on the bus
- High speed SPI master/slave programming up to 12.5 MHz SPI
- Level shifting 0.9 V – 3.3 V
- USB 2.0/Ethernet connectivity
The Promira SPI Slave can also operate 16 bit data transactions without delay. The Promira SPI Master has td setup (0 to 0.05 us) between two bytes of 8 bits. For additional information about signal timing, please refer to section 2.3 and section 6.2 of the Promira Serial Platform User Manual.
Additional resources that you may find helpful include the following:
- Aardvark I2C/SPI Host Adapter User Manual
- Cheetah SPI Host Adapter User Manual
- Promira Serial Platform User Manual
We hope this answers your question. If you have other questions about our SPI host adapters or other Total Phase products, feel free to email us at sales@totalphase.com, or if you already own one of our devices and have a technical question, please submit a request for technical support.