Overview
The VG4616321(2) SGRAM is a high-speed CMOS synchronous graphics RAM containing 16M bits. It is internally configured as a dual 256K x 32 DRAM with a synchronous interface (all signals are registered on the positive edge of the clock signal, CLK). Each of the 256K x 32 bit banks is organized as 1024 rows by 256 columns by 32 bits. Read and write accesses to the SGRAM are burst oriented; accesses start at a selected location and continue for a programmed number of locations in a programmed sequence. Accesses begin with the registration of a BankActivate command which is then followed by a Read or Write command.

FEATUREs
• Fast access time from clock: 4.5/5/5.5ns
• Fast clock rate: 200/166/143 MHz
• Fully synchronous operation
• Internal pipelined architecture
• Dual internal banks(256K x 32-bit x 2-bank)
• Programmable Mode and Special Mode registers
    - CAS Latency: 1, 2, or 3
    - Burst Length: 1, 2, 4, 8, or full page
    - Burst Type: interleaved or linear burst
    - Burst Read Single Write
    - Load Color or Mask register
• Burst stop function
• Individual byte controlled by DQM0-3
• Block write and write-per-bit capability
• Auto Refresh and Self Refresh
• 2048 refresh cycles/32ms
• Single + 3.3V ±0.3V power supply
• Input Reference Voltage : Vref = 1.5V ±0.2V
• Interface: LVTTL and SSTL_3
• JEDEC 100-pin Plastic QFP package