IDT72P51777L7-5BBI IDT, Integrated Device Technology Inc, IDT72P51777L7-5BBI Datasheet - Page 46

• Manufacturer Part Number: IDT72P51777L7-5BBI
• Description: IC FLOW CTRL 40BIT 376-BGA
• Manufacturer: IDT, Integrated Device Technology Inc

Specifications of IDT72P51777L7-5BBI

• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 72P51777L7-5BBI

QUEUE MARKing
write and/or re-read information that is stored into a queue.
operation is port independent. The same queue can be marked by the write port
and the read port simultaneously. Only the active queue can be MARKed,
multiple queues can NOT be MARKed by a port. A port (write or read) may only
designate one queue MARKed at a time. Upon a queue switch a decision must
be made as to whether to return to the Marked location or the last access address.
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IDT72P51767/72P51777 1.8V, MULTI-QUEUE FLOW-CONTROL DEVICES
(128 QUEUES) 40 BIT WIDE CONFIGURATION 5,898,240 and 11,796,480 bits
The overall intent of the MARK function is to provide the ability to either re-
A queue can be MARKed by either the write port or the read port. The MARK
@QS-1, if REN=0 and RADEN=1, Present Queue will be updated in QS0, QS1, and QS2, and the data from the Next Queue (NQ) will be available in QS4.
@QS-1, if REN=1 and RADEN=1, Present Queue will not be updated QS0-QS2. The Next time PQ is selected, the data will be from the last updated location.
@QS0, RADEN status is used to determine if a “mark” is requested for NQ. If RADEN=1 in QS0, NQ will be marked. In IDT mode, first NQ position after
QS is marked (latch RFCR values before QS3), data can’t overwrite this location.
@QS-1, if WEN=0 and WADEN=1, PQ will be updated in QS0,1, and 2, and NQ data will be written in QS3.
@QS-1, if WEN_N=1 and WADEN=1, there is no update for PQ during QS0-QS2. Next time PQ is switched back, data will be written into last update
location (rewrite).
@QS0, WADEN status is used to determine if a “mark” is requested for NQ. If WADEN=1 in QS0, NQ will be marked. In IDT mode, the first NQ
position after QS is marked (latch WFCR values before QS3), data can’t be read out beyond this location.
@QS0, if WADEN=0, NQ is not marked.
RADEN
QOUT
RCLK
WADEN
REN
WCLK
WEN
DIN
QS
QS
QS-1
A
QS-1
A
Present Queue (PQ)
Figure 24. MARK and Re-Write Sequence
Figure 25. MARK and Re-Read Sequence
QS0
B
QS0
Present Queue
B
QS1
C
QS1
C
QS2
D
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MARK AND REWRITE/ MARK AND REREAD
Standard Mode). Queues on the Write Port are MARKed using the WCLK &
WADEN signals. Queues on the Read Port are MARKed using the RCLK and
RADEN signals. Refer to the following timing diagrams for additional queue
MARK details. Refer to Figure 24 and 25 for further information.
QS2
D
The MARK functionality operates in any mode combination (BOI mode, IDT
QS3
E
QS3
E
Next Queue (NQ)
QS4
F
Next Queue
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
6724 drw29
FEBRUARY 11, 2009
6724 drw30