Document
IS61DDP2B22M18A/A1/A2 IS61DDP2B21M36A/A1/A2
2Mx18, 1Mx36 36Mb DDR-IIP (Burst 2) CIO SYNCHRONOUS SRAM
(2.0 Cycle Read Latency)
ADVANCED INFORMATION JULY 2012
FEATURES
DESCRIPTION
1Mx36 and 2Mx18 configuration available.
On-chip Delay-Locked Loop (DLL) for wide data valid window.
Common I/O read and write ports.
Synchronous pipeline read with self-timed late write operation.
Double Data Rate (DDR) interface for read and write input ports.
2.0 cycle read latency.
Fixed 2-bit burst for read and write operations.
Clock stop support.
Two input clocks (K and K#) for address and control registering at rising edges only.
Two echo clocks (CQ and CQ#) that are delivered simultaneously with data.
+1.8V core power supply and 1.5, 1.8V VDDQ, used with 0.75, 0.9V VREF.
HSTL input and output interface.
Registered addresses, write and read controls, byte writes, data in, and data outputs.
Full data coherency.
Boundary scan using limited set of JTAG 1149.1 functions.
Byte write capability.
Fine ball grid array (FBGA) package: 13mmx15mm and 15mmx17mm body size 165-ball (11 x 15) array
Programmable impedance output drivers via 5x user-supplied precision resistor.
Data Valid Pin (QVLD).
ODT (On Die Termination) feature is supported optionally on data input, K/K#, and BWx#.
The end of top mark (A/A1/A2) is to define options. IS61DDP2B21M36A : Don’t Care ODT function and pin connection IS61DDP2B21M36A1 : Option1 IS61DDP2B21M36A2 : Option2 Refer to more detail description at page 6 for each ODT option.
The 36Mb IS61DDP2B21M36A/A1/A2 and IS61DDP2B22M18A/A1/A2 are synchronous, highperformance CMOS static random access memory (SRAM) devices. These SRAMs have a common I/O bus. The rising edge of K clock initiates the read/write operation, and all internal operations are self-timed. Refer to the Timing Reference Diagram for Truth Table for a description of the basic operations of these DDR-IIP (Burst of 2) CIO SRAMs.
Read and write addresses are registered on alternating rising edges of the K clock. Reads and writes are performed in double data rate.
The following are registered internally on the rising edge of the K clock:
Read/write address
Read enable
Write enable
Byte writes
Data-in for first burst address
Data-Out for first burst address The following are registered on the rising edge of the K# clock:
Byte writes
Data-in for second burst address
Data-Out for second burst address
Byte writes can change with the corresponding data-in to enable or disable writes on a per-byte basis. An internal write buffer enables the data-ins to be registered one cycle after the write address. The first data-in burst is clocked one cycle later than the write command signal, and the second burst is timed to the following rising edge of the K# clock.
During the burst read operation, the data-outs from the first bursts are updated from output registers of the third rising edge of the K clock (starting two clock cycles later af.