CY7C4245V-25ASC Cypress Semiconductor Corp, CY7C4245V-25ASC Datasheet - Page 17

• Manufacturer Part Number: CY7C4245V-25ASC
• Manufacturer: Cypress Semiconductor Corp

Specifications of CY7C4245V-25ASC

• Configuration: Dual
• Density: 64Kb
• Access Time (max): 15ns
• Word Size: 18b
• Organization: 4Kx18
• Sync/async: Synchronous
• Expandable: Yes
• Bus Direction: Uni-Directional
• Package Type: TQFP
• Clock Freq (max): 40MHz
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (min): 3V
• Operating Supply Voltage (max): 3.6V
• Supply Current: 30mA
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 64
• Lead Free Status / RoHS Status: Not Compliant

Switching Waveforms
Notes
Document #: 38-06029 Rev. *D
24. PAF offset = m. Number of data words written into FIFO already = 256 − m + 1 for the CY7C4205V, 512 − m + 1 for the CY7C4215V. 1024 − m + 1 for the CY7C4225V,
25. PAF is offset = m.
26. 256 – m words inCY7C4205V, 512 − m words in CY7C4215V. 1024 – m words in CY7C4225V, 2048 − m words in CY7C4235V, and 4096 – m words in CY7C4245V.
27. 256 − m + 1 words in CY7C4205V, 512 − m +1 words in CY7C4215V, 1024 − m + 1 CY7C4225V, 2048 − m + 1 in CY74235V, and 4096 − m + 1 words in CY7C4245V.
28. If a write is performed on this rising edge of the write clock, there will be Full – (m–1) words of the FIFO when PAF goes LOW.
29. PAF offset = m.
30. t
2048 − m + 1 for the CY7C4235V, and 4096 − m + 1 for the CY7C4245V.
and the rising edge of WCLK is less than t
SKEW3
WCLK
WCLK
RCLK
PAF
RCLK
WEN
WEN
REN
is the minimum time between a rising RCLK and a rising WCLK edge for PAF to change state during that clock cycle. If the time between the edge of RCLK
REN
PAF
[25]
Figure 15. Programmable Almost Full Flag Timing (applies only in SMODE (SMODE in LOW))
t
CLKH
FULL – (M + 1) WORDS
(continued)
SKEW3
IN FIFO
Figure 14. Programmable Almost Full Flag Timing
t
CLKH
, then PAF may not change state until the next WCLK rising edge.
t
ENS
t
ENH
t
CLKL
Note 24
Note 29
Note 28
t
ENS
t
ENH
t
CLKL
t
PAF
t
PAF
t
t
ENS
ENS
FULL − M WORDS
t
SKEW3
FULL − M WORDS
IN FIFO
IN FIFO
[30]
t
ENS
[26]
t
PAF
t
[26]
ENH
CY7C4225V/4215V
CY7C4235V/4245V
FULL − (M + 1) WORDS
t
IN FIFO
PAFsynch
Page 17 of 23
[27]
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