Serviceable Flash Module
LSI SFMs have an advantage over the traditional hard disk drives (HDDs) because of their ability to access data completely electronically instead of electromechanically, resulting in superior transfer speed and mechanical ruggedness. SFMs are more reliable than HDDs, because they have no moving mechanical components and require significantly less power supply.
The Serviceable Flash Module is a field replaceable unit (FRU), because it is not mounted or attached directly into the card. The connection of SFM to the card is through a SAS/SATA cable. This means, if there is a SFM failure, you can service it by removing the SFM and replacing it with a new SFM.
The following figure illustrates a direct-connect configuration. The Inter-IC (I2C) interface communicates with peripherals. The external memory bus provides a 32-bit memory bus, parity checking, and chip select signals for pipelined synchronous burst static random access memory (PBSRAM), non-volatile static random access memory (NVSRAM), and Flash ROM. The card can connect to an internal drive bay that uses Serviceable Flash Modules.
Figure 1. Example of an LSI SAS Direct-Connect Application
