IDT72V51556L6BB8 IDT, Integrated Device Technology Inc, IDT72V51556L6BB8 Datasheet - Page 19
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IDT72V51556L6BB8
Manufacturer Part Number
IDT72V51556L6BB8
Description
IC FLOW CTRL MULTI QUEUE 256-BGA
Manufacturer
IDT, Integrated Device Technology Inc
Datasheet
1.IDT72V51546L7-5BB8.pdf
(58 pages)
Specifications of IDT72V51556L6BB8
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Other names
72V51556L6BB8
TABLE 2 — READ ADDRESS BUS, RDADD[7:0]
READ QUEUE SELECTION AND READ OPERATION (STANDARD MODE)
configured up to a maximum of 32 queues which data can be read via a common
read port using the data outputs (Qout), read clock (RCLK) and read enable
(REN). An output enable, OE control pin is also provided to allow High-
Impedance selection of the Qout data outputs. The multi-queue device read
port operates in a mode similar to “First Word Fall Through” on a SuperSync
IDT FIFO, but with the added feature of data output pipelining (see Figure 10,
Write Operations & First Word Fall Through). The queue to be read is selected
by the address presented on the read address bus (RDADD) during a rising
edge on RCLK while read address enable (RADEN) is HIGH. The state of REN
does not impact the queue selection. The queue selection is requires 2 RCLK
cycles. All subsequent data reads will be from this queue until another queue
is selected.
the device as opposed to Packet Mode where complete packets may be read.
The read port is designed such that 100% bus utilization can be obtained. This
means that data can be read out of the device on every RCLK rising edge
including the cycle that a new queue is being addressed.
(see Figure 12, Read Queue Select, Read Operation). RADEN goes high
signaling a change of queue (clock cycle “D”). The address on RDADD at that
time determines the next queue. Data presented during that cycle (“D”) will be
read at “D” (+ t
is active LOW. If REN is HIGH (inactive) for this clock cycle, data will not be read
from the previous queue. The next cycle’s rising edge (“E”), the read port
discrete empty flag will update to show the empty status of the newly selected
IDT72V51546/72V51556 3.3V, MULTI-QUEUE FLOW-CONTROL DEVICES
(32 QUEUES) 36 BIT WIDE CONFIGURATION 1,179,648 and 2,359,296 bits
The IDT72V51546/72V51556 multi-queue flow-control devices can be
Standard mode operation is defined as individual words will be read from
Changing queues requires a minimum of two RCLK cycles on the read port
A
), can be read from the active (old) queue (Q
Read Queue
PAEn/PRn
Quadrant
Operation RCLK
Select
Select
P
), provided REN
RADEN
1
0
Quadrant
Address
00
01
10
11
ESTR
19
0
1
queue (Q
word from the previous (old) queue (Q
queue (Q
the OE is asserted) consecutively (cycles “E” and “F” respectively) following
the selection of the new queue regardless of the state of REN, unless the new
queue (Q
queue will be prevented. Data cannot be read from an empty queue. The last
word in the data output register (from the previous queue), will remain on the
data bus, but the output valid flag, OV will go HIGH, to indicate that the data
present is no longer valid. This pipelining effect provides the user with 100%
bus utilization, and brings about the possibility that a “NULL” queue may be
required within a multi-queue device. Null queue operation is discussed in the
next section. Remember that OE allows the user to place the data output bus
(Qout) into High-Impedance and the data can be read in to the output register
regardless of OE.
12, 14, and 15 for read queue selection and read port operation timing
diagrams.
PACKET MODE OPERATION (PKT = HIGH on Master Reset)
packets or frames can be written to the device as opposed to Standard mode
where individual words are written. For clarification, in Packet Mode, a packet
can be written to the device with the starting location designated as Transmit
Start of Packet (TSOP) and the ending location designated as Transmit End
of Packet (TEOP). In conjunction, a packet read from the device will be
designated as Receive Start of Packet (RSOP) and a Receive End of Packet
Refer to Table 2, for Read Address Bus arrangement. Also, refer to Figures
The Packet mode operation provides the capability where, user defined
Queue Status on PAEn/PRn Bus
Q0 : Q7 → PAE0 : PAE7
Q8 : Q15 → PAE0 : PAE7
Q16 : Q23 → PAE0 : PAE7
Q24 : Q31 → PAE0 : PAE7
Device Select
(Compared to
ID0,1,2)
Device Select
(Compared to
ID0,1,2)
F
F
F
7 6 5
7 6 5
). Both of these words will fall through to the output register( provided
) is empty. If the newly selected queue is empty, any reads from that
). The internal pipeline is also loaded at this time (“D”) with the last
RDADD[7:0]
Read Queue Address
(5 bits = 32 Queues)
4 3 2
4 3 2
X
X
X Quadrant
COMMERCIAL AND INDUSTRIAL
P
) as well as the next word from the new
Address
1 0
1 0
5904 drw06
TEMPERATURE RANGES