IS61QDB21M36C
IS61QDB21M36C is 36Mb QUAD Synchronous SRAM manufactured by ISSI.
- Part of the IS61QDB22M18C comparator family.
- Part of the IS61QDB22M18C comparator family.
FEATURES
- 1Mx36 and 2Mx18 configuration available.
- On-chip Delay-Locked Loop (DLL) for wide data valid window.
- Separate independent read and write ports with concurrent read and write operations.
- Synchronous pipeline read with EARLY write operation.
- Double Data Rate (DDR) interface for read and write input ports.
- 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 output clocks (C and C#) for data output control.
- 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.
DESCRIPTION
The Mb and are synchronous, high-performance CMOS static random access memory (SRAM) devices. These SRAMs have separate I/Os, eliminating the need for high-speed bus turnaround. The rising edge of K clock initiates the read/write operation, and all internal operations are self-timed. Refer to the for a description of the basic operations of these
SRAMs.
The input address bus operates at double data rate. The following are registered internally on the rising edge of the K clock:
- Read address
- Read enable
- Write enable
- Byte writes
- Data-in for early writes
The following are registered on the rising edge of the K# clock:
- Write address
- Byte writes
- Data-in for second burst addresses
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 half...