serial presence detect (PC) (SPD)

Serial Presence Detect (SPD) is a procedure standardized by the Joint Electron Device Engineering Council( JEDEC) for detecting the memory configuration when booting a personal computer.

The Serial Presence Detect method, which was introduced with SDRAM technology, is an alternative to the previous Parallel Presence Detect( PPD) method. SPD is implemented in a small EEPROM that contains precise information about the memory latch, its memory capacity, supply voltage, addressing and about permissible frequency and time parameters. In addition, the SPD contains manufacturer data, codes and part numbers.

The motherboard's Basic Input/Output System( BIOS) can read the SPD chip via the System Management Bus( SMBus).