851V25
52V25
CY7C0851V25
CY7C0852V25
ADVANCE INFORMATION
2.5V 64K/128K x 36
Sync Dual-Port Static RAM
Features
Functional Description
• True Dual-Ported memory cellsthatallow simultaneous
access of the same memory location
• Sync. Pipelined 4.5 Megabit devices
—64K x 36 organization (CY7C0851V25)
The CY7C0851V25/CY7C0852V25 is a 4.5-Megabit pipelined
synchronous true dual-port Static RAM. This is a high-speed,
low-power 2.5V CMOS dual-port static RAM. Two ports are
provided, permitting independent, simultaneous access for
reads from any location in memory. A particular port can write
to a certain location while the other port is reading that location
simultaneously. The result of writing to the same location by
more than one port at the same time is undefined. Registers
on control, address, and data lines allow for minimal set-up
and hold time.
—128K x 36 organization (CY7C0852V25)
• Pipelined output mode allows fast 100-MHz operation
• 0.18-micron CMOS for optimum speed/power
• High-speed clock to data access: 5 ns (max.)
• 2.5V Low operating power
During a read operation, data is registered for decreased cycle
—Active = 150 mA (typical)
time. Clock to data valid t
= 5 ns. Each port contains a burst
CD2
—Standby = 10 mA (typical)
counter on the input address register. After externally loading
the counter with the initial address the counter will self-incre-
ment the address internally (more details to follow). The inter-
nal write pulse width is independent of the duration of the R/W
input signal. The internal write pulse is self-timed to allow the
shortest possible cycle times.
• HSTL class 1 I/O (0.75 Vref)
• Counter wraparound control
—Internal mask register controls counter wraparound
—Counter-Interrupt flags to indicate wraparound
—Memory Block Retransmit Operation
• Counter readback on address lines
• Mask register readback on address lines
• Interrupt flags for message passing
• Global Master reset
• Width and Depth expansion capabilities
• Dual Chip Enables on both ports for easy depth expan-
sion
A HIGH on CE0 or LOW on CE1 for one clock cycle will power
down the internal circuitry to reduce the static power consump-
tion. One cycle is required with chip enables asserted to reac-
tivate the outputs.
Counter enable inputs are provided to stall the operation of the
address input and utilize the internal address generated by the
internal counter for fast interleaved memory applications. A
port’s burst counter is loaded when the port’s address strobe
(ADS) and (CNTEN) signals are LOW. When the port’s counter
enable (CNTEN) is asserted and the ADS is deasserted, the
address counter will increment on each LOW to HIGH transi-
tion of that port’s clock signal. This will read/write one word
from/into each successive address location until CNTEN is
deasserted. The counter can address the entire memory array
and will loop back to the start. Counter reset (CNTRST) is used
to reset the unmasked portion of the burst counter to 0s. A
counter-mask register is used to control the counter wrap. The
counter and mask register operations are described in more
detail in the following sections.
• Separate byte enables on both ports
• Commercial and Industrial temperature ranges
• IEEE 1149.1 JTAG boundary scan
• 172-ball BGA (1-mm pitch) (15 mm x 15 mm x 0.51 mm)
New features added to the CY7C0851V25/CY7C0852V25 in-
clude: readback of burst-counter internal address value on ad-
dress lines, counter-mask registers to control the counter
wrap-around and counter interrupt (CNTINT) flags, readback
of mask register value on address lines, retransmit functional-
ity, interrupt flags for message passing, JTAG for boundary
scan, and asynchronous Master Reset.
For the most recent information, visit the Cypress web site at www.cypress.com
Cypress Semiconductor Corporation
•
3901 North First Street
•
San Jose
•
CA 95134
•
408-943-2600
October 17, 2000