SDIO Peripheral?

Hello Nathan,

We are constantly evaluating technology to incorporate in our Tiva MCUs. Can you help me understand your use case? Reading your post, I believe you want to use SDIO (instead of SPI) for increased throughput to an external memory.

Thanks,

Alex

Alex,

TI has the best driver library and chip documentation of any of the Cortex-M silicon vendors by far (compared to NXP, ST, etc). It speeds time to development and puts you a level above the rest. However, compared to the other two previously listed vendors the chip selection is very poor. There are no packages smaller than 64 pins (after the discontinuation of the LM3S line) which makes size limited applications difficult. ST and NXP have made smart moves by creating replacements (Cortex-M0) for 8 and 16 bit applications. As an embedded software developer I (and everyone else I know) would much rather be able to stick with the same development environment/tool chain and have a diverse series of chips from TI to choose from.

Back to the question at hand. Both the other vendors offer many different chips with an SDIO peripheral. This allows the parallel (4 bit data and up to 48Mhz clock) to interface with uSD and MMC cards. With this significant increase in bandwidth one can focus on other tasks (sampling/signal processing), since throughput is close to ~20MB/s. The default example (with FATFS) for the LM4F232 eval board struggles to get bandwidth of 240kB/s. I was able to improve this using uDMA (for block writes) up to about 1MB/s. However, this is only acheiveable logging constantly without doing any other tasks. A SDIO peripheral would be a huge improvement to the line and would attract many customers.

Another issue is that the TM4C123GXL (launchpad) was a board many developers began using. Yet, the chip on it (TM4C1233H6PM) is one of the last to go into production? That makes no sense.

I'd love to stick with TI, but the constant flops: NRND entire LM3S lines, LM4F  namechange, difficulty getting parts, no SDIO peripheral, no small packages is almost making the crappy tools provided by other vendors seem bearable.

Nate

Hello Nate,

Thanks for the information and feedback. TI does understand the value in adding the SDIO peripheral and will evaluate adding this to our Tiva MCU offering. Please let me know how I can help with any additional questions you may have.

Thanks,

Alex

I also want to point out that certain WiFi modules are coming out now/soon that use SDIO either exclusively or as the preferred connectivity option (instead of SPI/UART). For example GainSpan has a new series coming out with SDIO.

Bill