Do you know what SPD means? Hee hee

SPD (Serial Presence Detect), which the author translates as "configuration (presence bit) serial detection", rather than "continuous presence detection", if you understand it literally, there is no problem with the translation of the latter, but from the perspective of its real intention and working method, the former is more accurate. Why? Let's talk about it in detail.

SPD is a set of configuration information about the memory module, such as the number of p-banks, voltage, row address, number of column addresses, bit width, various major operation sequences (such as CL, TRCD, TRP, TRAS, etc.) ......They are stored in a 256-byte EEPROM (ElectricallyErasableProgrammableReadOnly Memory).

In fact, in the SPD, the standard information specified by JEDEC uses only 128 bytes (and 128 bytes, which belong to the manufacturer's own private area). In general, one byte corresponds to at least one parameter, and some parameters require multiple bytes to represent (e.g. product serial number, manufacturer's ** in the Jedec organization).

Each bit in a byte may be used to represent a specific value for this parameter. Since there is a lot of information about SPD, I will not list them all here, and interested readers can refer to the relevant documentation.

The timing information in the SPD is written by the module manufacturer according to the characteristics of the memory chip used and written to EEPROM, and the main purpose is to assist the Northbridge chip to accurately adjust the physical timing parameters of the memory to achieve the best use effect. If the memory setting option is set to "by SPD" in the BIOS.

Then, when the computer is turned on, Northbridge will automatically configure the corresponding memory timing and control registers according to the parameter information in the SPD to avoid faults caused by human adjustment errors. Of course, in the case of DIYER, the timing and control parameters can also be adjusted freely (the physical parameters are still determined by SPD or Northbridge's own testing).

SPD (Surge Protective Device).

Definition: SPD is a surge protective device (surge

protection

device), this is an indispensable device in lightning protection of electronic equipment, and was often called "lightning arrester" in the past.

Or "overvoltage protector" is abbreviated as SPD in English. The sail function of the surge protector is to channel the power line into the power line.

The instantaneous overvoltage of the signal transmission line is limited to the voltage that the equipment or system can withstand, or the powerful lightning current can be discharged into the ground, protecting the protected equipment or system from damage caused by shock.

Medical SPD is the abbreviation of the first letters of the English word supply, processing (management) and distribution (distribution), which is a kind of first-chain management mode that is more respected by modern medical institutions. It is a centralized management method for in-hospital logistics such as push.

SPD has four meanings. The first meaning: the whole spelling for shangpindu, that is, "on the pinyin" pinyin initials spd.

Second meaning: sulfachlorpyridazine, sulfachlorpyridazine spd. The third meaning:

a symmetric and positive definite matrix. The fourth meaning: silicon photodiode.

surge protective device.

That is, it is commonly known as lightning protection and lightning arrester.

SPD (Surge Protective Device) - Surge arrester for low-voltage distribution systems.