全部博文（135）
2010年（135）
分类： LINUX
2010-02-08 14:27:29
Synchronous Serial Interface (SSI) is a widely used serial interface standard for industrial applications. SSI makes use of a current loop driver, often a RS-422 driver, for its physical layer. The number of bits per message can vary and it is common to have message lengths as long as 24 and 25 bits.
The SPI bus has the same signal names and function, but is at TTL levels and is used between chips on computer boards. This causes some overlap in terminology.
