CY7C4285-15ASC Cypress Semiconductor Corp, CY7C4285-15ASC Datasheet - Page 16

• Manufacturer Part Number: CY7C4285-15ASC
• Manufacturer: Cypress Semiconductor Corp

Specifications of CY7C4285-15ASC

• Configuration: Dual
• Density: 1.125Mb
• Access Time (max): 10ns
• Word Size: 18b
• Organization: 64Kx18
• Sync/async: Synchronous
• Expandable: Yes
• Bus Direction: Uni-Directional
• Package Type: TQFP
• Clock Freq (max): 66.7MHz
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (max): 5.5V
• Supply Current: 50mA
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 64
• Lead Free Status / Rohs Status: Not Compliant

Retransmit
The retransmit feature is beneficial when transferring packets
of data. It enables the receipt of data to be acknowledged by
the receiver and retransmitted if necessary.
The Retransmit (RT) input is active in the stand-alone and
width expansion modes. The retransmit feature is intended for
use when a number of writes equal to or less than the depth
of the FIFO have occurred and at least one word has been
read since the last RS cycle. A HIGH pulse on RT resets the inter-
Table 2. Flag Truth Table
Document #: 38-06008 Rev. *A
0
1 to n
(n+1) to 16384
16385 to (32768–(m+1))
(32768–m)
32768
Notes:
37. n = Empty Offset (Default Values: CY7C4275/CY7C4285 n = 127).
38. m = Full Offset (Default Values: CY7C4275/CY7C4285 n = 127).
[37]
7C4275 – 32K x 18
[38]
to 32767
Number of Words in FIFO
0
1 to n
(n+1) to 32768
32769 to (65536 –(m+1))
(65536–m)
65536
[37]
7C4285 – 64K x 18
[38]
to 65535
nal read pointer to the first physical location of the FIFO. WCLK and
RCLK may be free running but must be disabled during and t
after the retransmit pulse. With every valid read cycle after retransmit,
previously accessed data is read and the read pointer is incriminated
until it is equal to the write pointer. Flags are governed by the relative
locations of the read and write pointers and are updated during a
retransmit cycle. Data written to the FIFO after activation of RT are
transmitted also.
The full depth of the FIFO can be repeatedly retransmitted.
FF
H
H
H
H
H
L
PAF
H
H
H
H
L
L
HF
H
H
H
L
L
L
PAE
H
H
H
H
L
L
CY7C4275
CY7C4285
Page 16 of 21
EF
H
H
H
H
H
L
RTR
[+] Feedback