IDT72P51539L6BB IDT, Integrated Device Technology Inc, IDT72P51539L6BB Datasheet - Page 31

• Manufacturer Part Number: IDT72P51539L6BB
• Description: IC FLOW CTRL 36BIT 256-BGA
• Manufacturer: IDT, Integrated Device Technology Inc

Specifications of IDT72P51539L6BB

• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 72P51539L6BB

SWITCHING QUEUES ON THE READ PORT
control devices can be configured up to a maximum of 32 queues. Data is read
from a queue using the Data Output (Qout) bus, Read Clock (RCLK) and Read
Enable (REN) signals. Selecting a queue on the read port occurs by placing
the queue address on the Read Address bus (RDADD) during a rising edge
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 Read Address Bus (RDADD) bus and a
rising edge of Read Clock (RCLK) and Read Address Enable (RADEN) is
HIGH. There are no restrictions as to the order to which queues are selected
or switched into or out of.
NOTE:
PQ = Present Queue
NQ = Next Queue
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-
RADEN
RCLK
Qout
REN
RDADD
RADEN
RCLK
PQ
Queue
address
Figure 10. Read Port Switching Queues Signal Sequence
PQ
QS-1
Queue Switch Cycles
Figure 11. Switching Queues Bus Efficiency
Queue Switch Cycle
QS0
PQ
QS1
PQ
31
of RCLK while Read Address Enable (RADEN) is HIGH. For reference, the
state of Read Enable (REN) is a “Don’t Care” during a read port queue selection.
REN has significance during the queue mark operation. Selecting a queue
requires 4 WCLK cycles. Refer to Figure 10, Read Port Switching Queues
Signal Sequence.
the IDT 72P51539/72P51549/72P51559/72P51569 multi-queue flow-control
device can continue to read from the Present Queue (PQ). The Present Queue
is defined as the current selected queue. Refer to Figure 11, Switching Queues
Bus Efficiency.
For maximum efficiency, during the 4 clock cycles required to switch queues
QS2
PQ
Queue
address
QS3
NQ
NQ
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
FEBRUARY 13, 2009
6715 drw16
6715 drw17