Solid-state disk
Embedded motherboards
MSC Q7-US15W-FD
I like to browse Web sites like Slashdot.org. Occasionally, their articles hit embedded topics, such as SanDisk’s 3-Gbit/s iSSD SATA II solid-state disk (Fig. 1).
Available in sizes up to 64 Gbytes, the iSSD comes in a 157-ball, 16- by 20-mm ball-grid array (BGA) with a 0.5-mm pitch. It consumes an average of 0.18 W and boasts a sequential read rate of 160 Mbytes/s and write speeds of 100 Mbytes/s. It also supports Self-Monitoring, Analysis, and Reporting Technology (SMART).
The user comments on sites like Slashdot.org are often enlightening or at least amusing. After the SanDisk announcement, many readers questioned the need for a chip like the iSSD, given all the other flash alternatives. When one reader suggested that it could be soldered to a motherboard, another reader asked why anyone would want to do that.
Of course, the reason would be obvious to Electronic Design readers who understand embedded requirements. Soldered components are good. Removable hardware is suspect. The advantages of the iSSD tend to be obvious to us, but many of the Slashdot readers were clueless. I wondered what they might think about some of the other uses of flash in an embedded environment.
Embedded USB Flash
Swissbit’s U-110 flash module might be closer to some users than the iSSD, since it plugs into the 10-pin USB headers found on standard PC motherboards as well as embedded motherboards (Fig. 2). The industrial flash drives come in capacities up to 8 Gbytes, which is more than enough to handle conventional operating systems like Linux or Windows Embedded Standard.
Like the iSSD, the U-110 lets developers utilize flash storage via a standard interface like SATA or USB. Even older motherboards can take advantage of IDE/PATA-based flash drives that aren’t much larger than the cable plug connector. The big plus for developers is that the built-in storage support in the BIOS and operating systems does not require changes to handle these flash drives.
Systems With Flash
Of course, flash on board is nothing new to embedded developers these days. Soldered flash chips have been the norm for ages. For example, Microcomputer Systems Components Vertriebs GMBH’s Atom-based MSC Q7-US15W-FD (Fig. 3) comes with flash soldered to its board.
The Qseven form factor board has a 1.6-GHz Z5x0 Atom processor. It comes with up to 2 Gbytes of DDR2 SDRAM and up to 4 Gbytes of flash memory. It also has eight USB interfaces and a SATA interface. The Phoenix SecureCore BIOS can boot from any of these interfaces as well as the on-board flash memory.
On-board and even on-chip flash memory will likely be standard fare for years to come. Still, standard interfaces like USB and SATA will offer interesting options as new nonvolatile memory technologies such as phase change memory come online. In the meantime, let me know if you hear about any more humorous misunderstandings of embedded hardware.
Microcomputer Systems Components Vertriebs GMBH
www.msc-ge.com
SanDisk
www.sandisk.com
Swissbit
www.swissbit.com