IDT72P51559L6BBI8 IDT, Integrated Device Technology Inc, IDT72P51559L6BBI8 Datasheet - Page 29

• Manufacturer Part Number: IDT72P51559L6BBI8
• Description: IC FLOW CTRL 36BIT 256-BGA
• Manufacturer: IDT, Integrated Device Technology Inc

Specifications of IDT72P51559L6BBI8

• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 72P51559L6BBI8

SWITCHING QUEUES ON THE WRITE PORT
control devices can be configured up to a maximum of 32 queues. Data is written
into a queue using the Data Input (Din) bus, Write Clock (WCLK) and Write
Enable (WEN) signals. Selecting a queue occurs by placing the queue address
control device supports changing (switching) queues every four (4) clock
cycles. To switch from the Present Queue (PQ) to another queue requires a
queue address to be placed on the Write Address Bus (WRADD) bus and a
rising edge of Write Clock (WCLK) and Write Address Enable (WADEN) is
HIGH. There are no restrictions as to the order to which queues are selected
or switched into or out of.
NOTES:
1. PQ = Present Queue
* Requires 4 clock cycles to switch queues.
IDT72P51539/72P51549/72P51559/72P51569 1.8V, MQ FLOW-CONTROL DEVICES
(32 QUEUES) 36 BIT WIDE CONFIGURATION 589, 824, 1,179,648, 2,359,296, and 4,718,592
The IDT 72P51539/72P51549/72P51559/72P51569 multi-queue flow-
The IDT 72P51539/72P51549/72P51559/72P51569 multi-queue flow-
NQ = Next Queue
WADEN
WCLK
WEN
Din
WRADD
WADEN
WCLK
PQ
Queue
address
Figure 7. Write Port Switching Queues Signal Sequence
QS-1
Queue Switch Cycles *
PQ
Figure 8. Switching Queues Bus Efficiency
Queue Switch Cycle
QS0
PQ
QS1
PQ
29
on the Write Address bus (WRADD) during a rising edge of WCLK while Write
Address Enable (WADEN) is HIGH. For reference, the state of Write Enable
(WEN) is a “Don’t Care” during a queue selection. WEN has significance during
the queue mark operation. Selecting a queue requires 4 WCLK cycles. Refer
to Figure 7, Write Port Switching Queues Signal Sequence.
the IDT 72P51539/72P51549/72P51559/72P51569 multi-queue flow-control
device can continue to write into the Present Queue (PQ). The Present Queue
is defined as the current selected queue. Refer to Figure 8, Switching Queues
Bus Efficiency.
QS2
For maximum efficiency, during the 4 clock cycles required to switch queues
NQ
Queue
address
QS3
NQ
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
6715 drw13
FEBRUARY 13, 2009
6715 drw14