CY7C4255-10AC Cypress Semiconductor Corp, CY7C4255-10AC Datasheet - Page 17

• Manufacturer Part Number: CY7C4255-10AC
• Description: IC DEEP SYNC FIFO 8KX18 64LQFP
• Manufacturer: Cypress Semiconductor Corp
• Series: CY7Cr

Specifications of CY7C4255-10AC

• Function: Synchronous
• Memory Size: 144K (8K x 18)
• Data Rate: 100MHz
• Access Time: 8ns
• Voltage - Supply: 3.3V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 64-LQFP
• Configuration: Dual
• Density: 144Kb
• Access Time (max): 8ns
• Word Size: 18b
• Organization: 8Kx18
• Sync/async: Synchronous
• Expandable: Yes
• Bus Direction: Uni-Directional
• Package Type: TQFP
• Clock Freq (max): 100MHz
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (max): 5.5V
• Supply Current: 45mA
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 64
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 428-1230

Width Expansion Configuration
The CY7C4255/65 can be expanded in width to provide word
widths greater than 18 in increments of 18. During width ex-
pansion mode all control line inputs are common and all flags
are available. Empty (Full) flags should be created by ANDing
Document #: 38-06004 Rev. *A
FULL FLAG (FF)
Figure 1. Block Diagram of 8K x18/16K x 18 Synchronous FIFO Memory Used in a Width Expansion Configuration
DATA IN (D)
PROGRAMMABLE(PAE)
HALF FULL FLAG (HF)
WRITE CLOCK (WCLK)
WRITE ENABLE (WEN)
LOAD (LD)
36
18
FF
RESET (RS)
7C4255
7C4265
WRITE EXPANSION IN (WXI)
READ EXPANSION IN (RXI)
EF
FIRST LOAD (FL)
18
18
the Empty (Full) flags of every FIFO; the PAE and PAF flags
can be detected from any one device. This technique will avoid
reading data from, or writing data to the FIFO that is “stag-
gered” by one clock cycle due to the variations in skew be-
tween RCLK and WCLK. Figure 1 demonstrates a 36-word width
by using two CY7C4255/65s.
FF
RESET (RS)
7C4255
7C4265
EF
READ CLOCK (RCLK)
READ ENABLE (REN)
OUTPUT ENABLE (OE)
PROGRAMMABLE (PAF)
18
DATA OUT (Q)
EMPTY FLAG (EF)
4255–24
CY7C4255
CY7C4265
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