Description
The IDT70T651/9 is a high-speed 256/128K x 36 Asynchronous Dual-Port Static RAM. The IDT70T651/9 is designed to be used as a stand-alone 9216/4608K-bit Dual-Port RAM or as a combination MAS TER/SLAVE Dual-Port RAM for 72-bit-or-more word system. Using the IDT MASTER/SLAVE Dual-Port RAM approach in 72-bit or wider memory system applications results in full-speed, error-free operation without the need for additional discrete logic.
This device provides two independent ports with separate control, address, and I/O pins that permit independent, asynchronous access for reads or writes to any location in memory. An automatic power down feature controlled by the chip enables (either CE0 or CE1) permit the on-chip circuitry of each port to enter a very low standby power mode.
The IDT70T651/9 has a RapidWrite Mode which allows the designer to perform back-to-back write operations without pulsing the R/W input each cycle. This is especially significant at the 8 and 10ns cycle times of the IDT70T651/9, easing design considerations at these high perfor mance levels.
The 70T651/9 can support an operating voltage of either 3.3V or 2.5V on one or both ports, controlled by the OPT pins. The power supply for the core of the device (VDD) is at 2.5V.

FEATUREs
◆ True Dual-Port memory cells which allow simultaneous access of the same memory location
◆ High-speed access
   – Commercial: 8/10/12/15ns (max.)
   – Industrial: 10/12ns (max.)
◆ RapidWrite Mode simplifies high-speed consecutive write cycles
◆ Dual chip enables allow for depth expansion without external logic
◆ IDT70T651/9 easily expands data bus width to 72 bits or more using the Master/Slave select when cascading more than one device
◆ M/S = VIH for BUSY output flag on Master, M/S = VIL for BUSY input on Slave
◆ Busy and Interrupt Flags
◆ On-chip port arbitration logic
◆ Full on-chip hardware support of semaphore signaling between ports
◆ Fully asynchronous operation from either port
◆ Separate byte controls for multiplexed bus and bus matching compatibility
◆ Sleep Mode Inputs on both ports
◆ Supports JTAG features compliant to IEEE 1149.1
◆ Single 2.5V (±100mV) power supply for core
◆ LVTTL-compatible, selectable 3.3V (±150mV)/2.5V (±100mV) power supply for I/Os and control signals on each port
◆ Available in a 256-ball Ball Grid Array, 208-pin Plastic Quad Flatpack and 208-ball fine pitch Ball Grid Array.
◆ Industrial temperature range (–40°C to +85°C) is available for selected speeds