Memory use in automotive

According to IC insights estimates, the automotive segment of the IC market is the fastest growing in the industry – at 10.8% per year between 2013 and 2018. We all know that current automobiles are loaded with microprocessors and DSPs – 52 CPUs in some high-end vehicles, with many of those multi-core. We also know automobiles are continuing to add technology – especially in the form of ADAS (advanced driver assistance systems) and that this will eventually include self-driving cars. What about memory usage in cars?

A surprising amount of DRAM, NAND flash, NOR flash, and SSD storage is used in the modern automobile. Kris Baxter Senior Marketing Director at Micron Technology told me that “the infotainment, the instrument cluster, and the driver assistance areas need lots of memory. Current model cars use 16 to 256 Gbytes of DRAM and flash total.” Micron is the leader in automotive memory at present.

Kris Baxter Senior. Marketing Director at Micron Technology.

Autos have a great need for fast boot. The engine control unit, the instrument cluster, and the rear-view camera all need to come to life very fast, and that usually takes NOR flash. SLC and MLC NAND flash are getting faster and more reliable, but the combination of high temperature, high read/write endurance, long lifetime and speed often point to SLC NAND flash for a good deal of the non-fast boot applications. Managed NAND flash is also used a lot to achieve the required 10-year lifetime.

Of all the automotive applications, ADAS is the fastest growing area. The multiple cameras and the processing analytics that go with them use considerable amounts both DRAM and flash. Also, other sensors on the car need data analysis. The majority of memory used is in ADAS low power DRAM with a wide x32 bus. A number of these applications are moving to LPDDR2 now, with LPDDR4 on the horizion.

Mapping systems also take a lot of memory as does infotainment (where mapping resides) with new systems using DDR3/4 Standard DRAM and LPDDR4/LPDRAM in the high resolution graphic display units. Some cars still have a hard disk drive for storing maps and the like, but, due to the need for ruggedness and long lifetime, this is quickly moving to SSD and e.MMC.

Another key requirement for automakers is for higher temperature devices. 105°C is minimum, and -40° to 125°C is commonplace, and this is not for the engine control, it’s for instruments and ADAS. A second automaker requirement is for high reliability. The component failure rate needs to be proven to be very low and all memory ICs that Micron makes for automotive are AEC-Q100 qualified. They are also made in ISO standard qualified manufacturing facilities.

Micron’s G18 family of x16 flash parallel NOR devices are capable of 266 Mbyte/s transfer rates and operate over -40° to 105°C. Built with a 65 nm process and sixth generation MLC NOR technology, they have densities of 32 or 64, or 128 Mbytes, work from a 1.8 V supply, and come in a small 8 x 10 mm package.

Spansion (now part of Cypress) and Macronix also offer parallel NOR flash memory ICs.

Micron estimates ADAS memory requirements will grow 50% over the next two years, the cluster will grow at 25%, and the infotainment maybe 35%. One interesting strategy that Micron employs is providing its automotive clients with work areas in their R&D labs where they work together investigating and optimizing new designs. That idea seems to be working out very well, for both Micron and the automakers.