CN2490618Y

CN2490618Y - Device for DDRRAM and SDRAM symbiont in host board

Info

Publication number: CN2490618Y
Application number: CN 01208956
Authority: CN
Inventors: 何溪轩
Original assignee: Mitac International Corp
Current assignee: Mitac International Corp
Priority date: 2001-03-19
Filing date: 2001-03-19
Publication date: 2002-05-08
Anticipated expiration: 2011-03-19

Abstract

The utility model relates to a device for DDR RAM and SDRAM symbiont in host board; the utility model comprises a first slot arranged on the host board for inserting an SDRAM memory module, a second slot arranged on the host board for inserting a DDR RAM memory modules and a group of data lines which are connected to the first slot and the second slot respectively; the data lines are connected with a resistance, a switch and a voltage source according to the sequence; whether the resistance is connected with the voltage source or not depends on the ON or OFF of the switch; thereby achieving the efficacy of the symbiont of the SDRAM memory module and the DDR RAM memory modules on the same host board.

Description

DDR RAM and SDRAM coexist as the device of motherboard

The utility model is about a kind of DDR RAM and SDRAM coexisting apparatus.

Generally being typically provided with memory module slot (Socket) on motherboard plants for memory module (MemoryModule), and, can make CPU memory module be carried out access action by this north bridge interface by the bus that is connected between the Memory Controller on memory module slot and the motherboard (north bridge).And the normal a kind of memory module slot that uses mainly is the SDRAM memory module setting of more widely using at present on the present motherboard, so the electric interface (LVTTL) that designs on it is the demand that meets the SDRAM memory module; And in order to make data rate quicker, a kind of transmission speed is that Double Data Rate (DDR:Double DataRate) SDRAM of SDRAM twice is developed, and because the technology major part of DDR RAM is continued to use the technology of SDRAM, and size design is also equally matched with SDRAM, so its performance history is not difficult and cost of manufacture is also only slightly higher than SDRAM, but its transmission usefulness will be got well much than SDRAM, will become the market mainstream soon with its splendid transfer efficiency so estimate DDR RAM: still,, DDR RAM memory module can't be applicable to the motherboard of SDARM slot because having 184 foots pad (PAD) with 168 pins, and, because the employed electric interface of DDRRAM (SSTL-2) is different with SDRAM also, and being the data line that is the DDRRAM memory module, wherein main difference must be connected to one 1.25 volts the voltage that draws high by a terminal resistance (being generally 27 ohm), provide a working current to DDR RAM to draw high voltage by this, therefore use in order to mate DDR RAM, the dealer must develop the motherboard of the another kind of DDR RAM of being suitable for, yet this motherboard but can't use simultaneously for present more welcome and SDRAM memory module that be easy to obtain, therefore, even if the user has a mind to buy such motherboard, but may give up buying meaning because of present the obtaining difficulty of not widely used as yet DDR RAM memory module.

The purpose of this utility model is to provide a kind of DDR RAM and SDRAM to coexist as the device of motherboard, and DDRRAM and SDRAM all can be used on same motherboard.

According to above-mentioned from, DD RAM of the present utility model and SDRAM coexist as the device of motherboard, are characterized in that it comprises: be located at first slot and second slot on the motherboard; The one group of data line that is connected with this first slot and second slot respectively; Several resistance, respectively this resistance one end be respectively with the corresponding connection of each bar data line of this group data line; Several switches, respectively this switch one end be respectively with the corresponding connection of the described resistance other end; And one voltage source be to be connected with the described switch other end.

Adopt such scheme of the present utility model, can select this special despatch resistance whether to be connected by controlling described switch ON, OFF, thereby realize that DDR RA memory module and SDRAM memory module can coexist as the effect on the same motherboard with voltage source.

For further understanding the purpose of this utility model, characteristics and advantage, preferred embodiment of the present utility model is described in detail below in conjunction with accompanying drawing.

See also Fig. 1, it is the circuit diagram of the utility model one preferred embodiment, and the device that the DDR RAM of present embodiment and SDRAM coexist as motherboard comprises: be arranged at first slot 1 on the motherboard (not shown) and second slot 2, one group of data line 3, several resistance 4, several switches 5 and voltage source V _TTWherein, first slot 1 and second slot 2 can be to be set up in parallel more than one, but in the present embodiment, be to be example all for convenience of description with one, first slot 1 mainly is to plant for the SDRAM memory module (not shown) of a 168PIN, and this second slot 2 mainly is for the more DDR RAM memory module (not shown) plant of the 184PIN of high speed; This group data line 3 is to be a data bus, it is connected with first slot 1 and second slot 2 respectively, and these group data line 3 one ends are to be connected to a Memory Controller (north bridge) 7, make CPU8 carry out access action by the memory module that 7 pairs of this Memory Controllers are inserted on first slot 1 or second slot 2; Respectively an end of this resistance 4 is organized the corresponding connection of each data line of data line 3 respectively with this, and its resistance value is generally 27 ohm, described resistance 4 other ends then respectively with the corresponding connection of described switch 5 one ends, and described switch 5 can be in the present embodiment a jumper wire device (Jumper) ,-MOSFET or electronic switch etc. have the element of ON, two sections selections of OFF, and this voltage source V _TTBe to be connected with the other end of described switch 5, and this voltage source V in the present embodiment _TTMagnitude of voltage be to be 1.25 volts; Take this, when described switch 5 is not shut (OFF), described resistance 4 and voltage source V _TTBe to be in not connected state, at this moment, motherboard is in the SDRAM suitable environment, so first slot 1 can use for plant SDRAM memory module, 2 of second slots are idle, so CPU8 can carry out access control by the SDRAM memory module on 3 pairs first slots 1 of this group data line by a Memory Controller 7; And when described switch 5 was shut (ON) simultaneously, described resistance 4 was and voltage source V _TTBe connected, at this moment, motherboard becomes the environment that meets DDR RAM use, DDR RAM memory module can be inserted in second slot 2 and use, leave unused and change first slotting poor 1, so CPU8 can carry out access control by the DDR RAM memory module in 3 pairs second slots 2 of this group data line by Memory Controller 7.

Hence one can see that, by being located at described resistance 4 and voltage source V _TTBetween described switch 5, the user only needs the state (ON or OFF) of configuration switch 5, can select motherboard to be to use DDR RAM memory module or SDRAM memory module arbitrarily, not only overcome the shortcoming that existing motherboard can't provide two kinds of different DRAM to use owing to itself designs, simultaneously the DRAM of described two kinds of different qualities all can have been used on same motherboard.

By preferred embodiment the utility model is illustrated by way of example above; but it will be appreciated that; every person skilled in the art person also can make the equivalent transformation of various parts according to spirit of the present utility model, and these equivalent transformations all should be included in the scope of patent protection of the present utility model.

Claims

1. DDR RAM and SD RAM coexist as the device of motherboard, it is characterized in that it comprises:

If first slot on the what motherboard;

If second slot on the what motherboard:

The one group of data line that is connected with above-mentioned first slot and second slot respectively;

Several resistance, respectively this resistance one end is distinguished corresponding connection with two data lines that this is organized in data line respectively;

Several switches, respectively this switch one end respectively with the corresponding connection of the described resistance other end: and

One voltage source, it is connected with the described switch other end.

2. DDR RAM as claimed in claim 1 and SD RAM coexist as the device of motherboard, it is characterized in that, this group data line one end is connected to a Memory Controller.

3. DDR RAM as claimed in claim 1 and SD RAM coexist as the device of motherboard, it is characterized in that, the resistance value of described resistance is looked demand between 27 to 33 ohm.

4. DDR RAM as claimed in claim 3 and SD RAM coexist as the device of motherboard, it is characterized in that, the magnitude of voltage of this voltage source is 1.25 volts.