GENERAL DESCRIPTION

The 256Mb SDRAM is a high-speed CMOS, dynamic random-access memory containing 268,435,456-bits. It is internally configured as a quad-bank DRAM with a synchronous interface (all signals are registered on the positive edge of the clock signal, CLK). Each of the 67,108,864-bit banks is organized as 4,096 rows by 512 columns by 32 bits.

FEATURES

• PC100 functionality

• Fully synchronous; all signals registered on positive edge of system clock

• Internal pipelined operation; column address can be changed every clock cycle

• Internal banks for hiding row access/precharge

• Programmable burst lengths: 1, 2, 4, 8, or full page

• Auto Precharge, includes CONCURRENT AUTO PRECHARGE, and Auto Refresh Modes

• Self Refresh Mode

• 64ms, 4,096-cycle refresh (15.6µs/row)

• LVTTL-compatible inputs and outputs

• Single +3.3V ±0.3V power supply

• Supports CAS latency of 1, 2, and 3