increase the SDRAM speed, it allows the clock pulse to rise along and down along the reading data, so its speed is the standard Sdra twice times.
DDR differs from SDRAM in terms of shape volume, and they have the same size and the same pin distance. But the DDR is 184 pins, 16 more pins than SDRAM, including new controls, clocks, power supplies and grounding signals. DDR memory uses the SSTL2 standard that supports the 2.5V voltage, rather than the 3.3V voltage LVTTL standard used by SDRAM.
rate in DDR I, and because of this, the frequency of the DDR I external clock pins is consistent with the core frequency within the chip. As shown in the prefetch process of DDR I, a 16-bit memory chip transmits 2 16bit data from the kernel to an external MUX unit at a time, and then transmits this 2 x 16bit to the North Bridge or other memory controller respectively on the clock signal, along the lower two times. The whole process goes through exactly the same time as a kernel clock cycle.
DDR2 Circuit DesignHigh-speed large-capacity cache is an essential hardware in high-speed big data applications. At present, the use of a wide range of high-speed large-capacity memory in FPGA system has a classical low-speed single data rate of SDRAM memory, and high-speed dual-rate DDR, DDR2, DDR3 type SDRAM memory, The DDR series of memory all require the FPGA chip has the corresponding hardware circuit
already discontinued, can buy is almost a small amount of inventory before, because less goods, the price is expensive. Finally, let's look at the difference between DDR2 and DDR3 memory.
The difference between DDR2 and DDR3:
Comparison of DDR2 and DDR3 memory parameters
At present, DDR2 and DDR3 are
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DDR2DDR2 (double data rate 2) SDRAM is a new generation of memory technology standard developed by JEDEC (Joint Committee for electronic equipment engineering). The biggest difference between it and the previous generation of DDR memory technology standards is that, although the same basic method of data transmission is adopted at the same time as the clock increase/decrease delay, DDR2 memory has twi
DDR2 (double data rate2) SDRAM is a new generation memory technical standard developed by JEDEC (Joint Committee for electronic equipment engineering). It is the biggest difference from the previous generation of DDR memory technical standards: although the basic method of transmitting data at the same time with the clock rising/falling edge, DDR2 has twice the DDR pre-read capability (that
Ddr2/ddr II (Double Data Rate 2) SDRAM is a new generation of memory technology standards developed by the JEDEC (Joint Commission on Electronic Equipment Engineering), the biggest difference from the previous generation of DDR memory technology standards, although it was adopted in the rise of the clock/ The basic way of data transfer at the same time, but DDR2 memory has twice times the previous generatio
Nowadays, in FPGA system design, the complexity of the system is getting higher and higher, and the requirements for memory are getting higher and higher. Generally, DDR2 has become the first choice for FPGA systems considering the overall volume and capacity. Here, we will make a summary of the DDR2 design for the cyclone IV series FPGA. The FPGA and DDR Design for other series are similar.
Environment: s5pc100 + Android (uboot 1.3.4)
DDR2 256 MB
Due to the low power consumption advantage of DDR2 compared with mobile DDR and the high power consumption requirement of the product itself, it is necessary to use dd2 instead of mobile DDR;
Uboot linked list u-boot.LDS from/board/Samsung/smdkc100
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DDR3 is expected to be born next year
The speed is soaring! AMD's AM2 Interface K8 architecture Processor introduced support for the highest DDR2 800, and Intel released its long-awaited Conroe processor on July 23 and carried out the largest "terrorist attack" in history, and the computer market appeared to have entered the DDR2 800 in 2006 ahead of time. RD600 supports 1500Mhz front-end bus overclocking,
I haven't seen anyone posting a 128 M DDR2 memory modification on the s3c2450 or s3c2416 in wince6.0ArticleIt's silly. Now it's all closed.
No way. Write it yourself.
The main changes are similar to those in section 2440, but note the following;
DCD 0x80000000, 0x30000000,128; 128 mb dram Bank 6
Offset (0x0400 0000)
DCD 0x90800000, 0x48000000, 1; SDRAM control register
1. Burst Length (BURSTLENGTH,BL)
Due to the DDR3 8bit, the burst transmission cycle (BURSTLENGTH,BL) is also fixed to 8, and for DDR2 and early DDR architecture system, BL=4 is also commonly used, DDR3 to add a 4bitBurstChop (sudden mutation) mode, That is, a bl=4 read operation combined with a bl=4 write operation to synthesize a bl=8 data burst transmission, then can control this burst mode by A12 address line. It should also be noted that any burs
Questions on msdn:
Continue memory expansionCodeResearch, with a new discovery: Mainly extends the oemenumextensiondram function in init. C.
1. Number of pins. the number of Gold finger pins in DDR memory is 184, while that in DDR2 memory and ddr3 memory is 240. 2. Memory particle shape. the size of the DDR memory is rectangular. The size of the DDR2 and ddr3 memory is square and
166MHz, memory frequency, mainly in the low-end video card use, DDR2 memory due to high cost and performance in general, so the use of a small amount. DDR3 memory is the most widely used memory type for high-end graphics. Different video memory can provide video memory frequency is also very different, mainly 400MHz, 500MHz, 600MHz, 650MHz, etc., high-end products also have 800MHz, 1200MHz, 1600MHz, or eve
controller, The whole process goes through exactly one core clock cycle.To DDR2, the chip core prefetch 4 times times the data to IO buffer, in order to further improve the outgoing speed, the core clock of the chip and the external interface clock (that is, we usually touch the clock pin clocks) is no longer the same as 1:, The external clock clock frequency changes to twice times the core clock. Similarly, DDR3 each time prefetch 8 times times the
BIOS, the BIOS will automatically read the SPD information, set the equivalent frequency of 800MHz, Then the operating frequency is 400MHz according to the formula, the first calculation of the frequency division coefficient, the original clock/set of operating frequencies into one, that is 2200/400= 5.5, then use 5.5 into one equals 6, the division factor is 6, and then the current main frequency divided by the frequency factor, because there is no
precharge delay (TRP) memory pre-charge time, and the row-active delay (TRAS) Memory line address is selected.DDR3 These parameters will be larger than DDR2, but it is not said DDR3 delay will be greater than DDR2, because the clock frequency of DDR3 is also relatively high, so the final absolute delay DDR3 Alsois relatively small. And the JEDEC set memory timing is conservative, memory module manufacturer
channels, than the refresh before the upgrade.
My 90 nm tk-55cpu, now memory running in dual channel 723, at 800 low frequency operation is voltage down to 0.9 volts. Full speed is 1.1 volts.
Spdtool Memory overclocking tool Download: http://www.cr173.com/soft/30207.html
This is the Refresh tool spdtools , below I teach you how to refresh their 667 memory to 800, very simple, as long as the change of 5 values on it. It is best to leave the memory only one on the mac
memory frequency is the same as CPU frequency, is used to represent the speed of memory, it represents the maximum operating frequency that memory can achieve. The memory frequency is measured in MHz (MHz). the higher the memory frequency is to a certain extent, the faster the memory can reach. The frequency of memory determines how often the memory can work correctly. Currently the more mainstream memory frequency rooms are 333MHz and 400MHz of DDR
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