The Semiconductor Group of Hitachi, Ltd. (TSE: 6501) today announced, as an 
industry first, 512-Mbyte 184-pin DDR*1 SDRAM DIMMs*2 containing 256-Mbit 
DDR synchronous DRAMs (DDR SDRAMs), for use as main memory in PCs, 
workstations, servers, and similar products.  Sample shipments of the unbuffered type 
HB54A5129FN Series and the registered type HB54A5129F1 Series will begin in 
January 2000 in Japan. These new DIMMs offer high-speed operation, with a data 
transfer rate of 2.1-Gbytes per second.

256-Mbyte 184-pin DDR SDRAM DIMMs of the unbuffered type HB54A2569FM 
Series and the registered type HB54A2569F1 Series are also developed and will start 
the sample shipment from January 2000 in Japan.  

The speed and performance of information device systems implementing network and 
multimedia applications continue to increase, bringing a demand for greater 
performance from the CPUs and memory devices used in such systems.  In particular 
demand are higher data transfer rates for the DRAMs used as main memory, and 
Hitachi has already released fast DDR SDRAMs achieving data transfer rates of 266-
Mbps/pin and 200-Mbps/pin.  Now, Hitachi has developed large-capacity 512-Mbyte 
and 256-Mbyte modules incorporating DDR SDRAMs.

512-Mbyte models employ a 64-Mword x 72-bit configuration and  256-Mbyte 
models employ a 32-Mword x 72-bit configuration. These products offer high-speed 
operation, with data transfer rates of  2.1-Gbytes per second and 1.6-Gbytes per 
second using 133MHz and 100MHz clocks. All power supply and input/output 
voltages are 2.5 V, and an SSTL-2*3 I/O interface is used, enabling high-speed, low-
power-consumption operation. The modules are JEDEC standard 184-pin socket type 
DIMMs.

These modules allow high-density mounting of DDR SDRAMs in various kinds of 
information devices, making it possible to implement large-capacity, high-speed 
information device systems. 

Future plans include the development of a 1-Gbyte registered DIMMs, using Hitachi's 
stacked TCP*4 mounting technology, together with further improvements in DDR 
SDRAM speed and capacity.

Notes:	1. DDR: Double Data Rate.  A data input/output method in which input/output                       
		is synchronized with both rises and falls of an external clock.
	2. DIMM: Dual In-line Memory Module
	3. SSTL-2: Stub Series Terminated Logic for 2.5V
        4. TCP: Tape Carrier Package

< Typical Applications >
Main memory or expansion memory for high-end workstations, servers, and PCs.

< Prices in Japan > (For Reference Only) 
Product Name					Sample Price (Yen)	
512-Mbyte DIMMs		HB54A5129FN		456,000  to  532,000
unbuffered type		Series						
512-Mbyte DIMMs		HB54A5129F1		480,000  to  560,000
registered type		Series						
256-Mbyte DIMMs		HB54A2569FM		240,000  to  280,000
unbuffered type		Series						
256-Mbyte DIMMs		HB54A2569F1		264,000  to  308,000
registered type		Series						


< Specifications >
Item			HB54A5129FN	HB54A5129F1	HB54A2569FM	HB54A2569F1	
Product			64 Mwords x	64 Mwords x	32 Mwords x	32 Mwords x 
configuration		72 bits		72 bits		72 bits		72 bits		
Buffering		Unbuffered	Buffered 	Unbuffered	Buffered 
					(PLL + register 		(PLL + register
					type)				type)		
Power supply 		2.5V +/- 0.2V
voltage											
Operating 		Clock:100MHz/133MHz
frequency		Data  :200MHz/266MHz						
Data transfer rate	1.6 Gbytes per second  /  2.1 Gbytes per second			
Burst length		2/4/8								
Burst sequence		Sequential/interleaved						
Refreshing		8 kcycles/64 ms							
Package			184-pin DIMM (Dual In-line Memory Module)