SPD
       Security Policy Database (SP, IPSec)

	

	SPD
       Serial Presence Detect (EEPROM, SDRAM)

	

	SPD
       Software Products Division

	

	SPD
       Software Product Description

	

	presence detect
Parallel Presence Detect
PPD
Serial Presence Detect
SPD

    A means of identifying a memory chip to the memory
   controller logic.  The original scheme, called Parallel
   Presence Detect (PPD) used a separate pin for each bit of
   information.  As the number of pins can not be very large this
   only allowed to identify the density and the speed of the
   chips.  To allow for additional information the Serial
   Presence Detect (SPD) scheme was introduced which uses a
   serial EEPROM to store the presence detect information and
   requires only two pins (one for enabling it and one for data).

   (1998-03-07)