FAQ: What is XiP?

Document created by PrasanthR Employee on Jul 25, 2013Last modified by PrasanthR Employee on Sep 23, 2013
Version 2Show Document
  • View in full screen mode

XiP is a mode in Flash memory where one can avoid sending commands, and only send address. Flash memory must be pre-configured to support this. The SPI Controller must also be programmed with CMDSKIP option. Since the commands are always sent in single line (even if Quad/Dual are chosen)  the advantage can be calculated as follows, for a case of Quad Mode with SPI Clock Freq equal to SCLK Clock Freq. Total SPI bursts can be obtained if one looks at the Cache Fill Counter values.

 

Total Core Clock Cycles with XiP = Total Core Clock Cycles without XiP - ((8 x Total SPI Bursts x CCLK:SCLK Ratio) - 1)

 

Note - Even if XiP Mode is not enabled, one can still Execute-In-Place from Flash memory. The major reason why XiP is called as mode is that, slow flash devices has to support fast code execution and hence user is expected to program the best case features (in this case command skip).

Attachments

    Outcomes