IDT72P51777L7-5BBI IDT, Integrated Device Technology Inc, IDT72P51777L7-5BBI Datasheet - Page 52

• 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

FLAG DESCRIPTION
PAFn FLAG BUS OPERATION
configured for up to 128 queues, each queue having its own almost full status.
An active queue has its flag status output to the discrete flags, FF and PAF, on
the write port. Queues that are not selected for a write operation can have their
PAF status monitored via the PAFn bus. The PAFn flag bus is 8 bits wide, so
that 8 queues at a time can have their status output to the bus. If 9 or more queues
are setup within a device then there are 2 methods by which the device can share
the bus between queues, “Direct” mode and “Polled” mode depending on the
state of the FM (Flag Mode) input during a Master Reset. If 8 or less queues
are setup within a device then each will have its own dedicated output from the
bus. If 8 or less queues are setup in single device mode, it is recommended to
configure the PAFn bus to polled mode as it does not require using the write
address (WRADD).
FULL FLAG OPERATION
The FF flag output provides a full status of the queue currently selected on the
write port for write operations. Internally the multi-queue flow-control device
monitors and maintains a status of the full condition of all queues within it, however
only the queue that is selected for write operations has its full status output to the
FF flag. This dedicated flag is often referred to as the “active queue full flag”.
will switch to the new queue and provide the user with the new queue status,
on the 3rd cycle after a new queue selection is made. The user then has a full
status for the new queue one cycle ahead of the WCLK rising edge that data
can be written into the new queue. That is, a new queue can be selected on
the write port via the WRADD bus, WADEN enable and a rising edge of WCLK.
On the 4th rising edge of WCLK, the FF flag output will show the full status of the
newly selected queue. On the forth rising edge of WCLK following the queue
selection, data can be written into the newly selected queue provided that data
and enable setup & hold times are met.
cycle after queue selection, which is one cycle before data can be written to that
queue. This prevents the user from writing data to a queue that is full, (assuming
that a queue switch has been made to a queue that is actually full).
based on a rising edge of WCLK. Internally the multi-queue device monitors and
keeps a record of the full status for all queues. It is possible that the status of a
FF flag maybe changing internally even though that flag is not the active queue
flag (selected on the write port). A queue selected on the read port may
experience a change of its internal full flag status based on read operations.
Operation and Figure 45, Full Flag Timing in Expansion Configuration for timing
information.
EXPANSION CONFIGURATION - FULL FLAG OPERATION
flags of all devices should be connected together, such that a system controller
monitoring and managing the multi-queue devices write port only looks at a
single FF flag (as opposed to a discrete FF flag for each device). This FF flag
is only pertinent to the queue being selected for write operations at that time.
Remember, that when in expansion configuration only one multi-queue device
can be written to at any moment in time, thus the FF flag provides status of the
active queue on the write port.
IDT72P51767/72P51777 1.8V, MULTI-QUEUE FLOW-CONTROL DEVICES
(128 QUEUES) 40 BIT WIDE CONFIGURATION 5,898,240 and 11,796,480 bits
The IDT72P51767/72P51777 multi-queue flow-control device can be
The multi-queue flow-control device provides a single Full Flag output, FF.
When queue switches are being made on the write port, the FF flag output
Note, the FF flag will provide status of a newly selected queue three WCLK
The FF flag is synchronous to the WCLK and all transitions of the FF flag occur
See Figure 42, SDR Write Queue Select, Write Operation and Full Flag
When multi-queue devices are connected in Expansion configuration the FF
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output have a High-Impedance capability, such that when a queue selection is
made only a single device drives the FF flag bus and all other FF flag outputs
connected to the FF flag bus are placed into High-Impedance. The user does
not have to select this High-Impedance state, a given multi-queue flow-control
device will automatically place its FF flag output into High-Impedance when none
of its queues are selected for write operations.
flag output of that device will maintain control of the FF flag bus. Its FF flag will
simply update between queue switches to show the respective queue full status.
on the 1-3 bit ID code (1 if two multi-queue are configured with a maximum total
of 256 queues, 2 if four devices are used totalling a maximum of 256 queues,
and 3 if there are up to eight devices with a maximum total of 256 queues) found
in the 1-3 most significant bits of the write queue address bus, WRADD. If the
1-3 most significant bits of WRADD match the 1-3 bit ID code setup on the static
inputs, ID0, ID1 and ID2 then the FF flag output of the respective device will be
in a Low-Impedance state. If they do not match, then the FF flag output of the
respective device will be in a High-Impedance state. See Figure 45, Full Flag
Timing in Expansion Configuration for details of flag operation, including when
more than one device is connected in expansion.
EMPTY FLAG OPERATION (EF)
The rising edge of an RCLK cycle that places new data onto the output register
of the read port. Internally the multi-queue flow-control device monitors and
maintains a status of the empty condition of all queues within it.
timing.
EXPANSION – EMPTY FLAG OPERATION
flags of all devices should be connected together, such that a system controller
monitoring and managing the multi-queue devices read port only looks at a
single EF flag (as opposed to a discrete EF flag for each device). This EF flag
is only pertinent to the queue being selected for read operations at that time.
Remember, that when in expansion configuration only one multi-queue device
can be read from at any moment in time, thus the EF flag provides status of the
active queue on the read port.
output have a High-Impedance capability, such that when a queue selection is
made only a single device drives the EF flag bus and all other EF flag outputs
connected to the EF flag bus are placed into High-Impedance. The user does
not have to select this High-Impedance state, a given multi-queue flow-control
device will automatically place its EF flag output into High-Impedance when none
of its queues are selected for read operations.
flag output of that device will maintain control of the EF flag bus. Its EF flag will
simply update between queue switches to show the respective queue status.
on the 1-3 bit ID code (1 if two multi-queue are configured with a maximum total
of 256 queues, 2 if four devices are used totalling a maximum of 256 queues,
and 3 if there are up to eight devices with a maximum total of 256 queues) found
in the 3 most significant bits of the read queue address bus, RDADD. If the 3 most
significant bits of RDADD match the 1-3 bit ID code setup on the static inputs, ID0,
ID1 and ID2 then the EF flag output of the respective device will be in a Low-
Impedance state. If they do not match, then the EF flag output of the respective
device will be in a High-Impedance state.
This connection of flag outputs to create a single flag requires that the FF flag
When queues within a single device are selected for write operations, the FF
The multi-queue device places its FF flag output into High-Impedance based
The multi-queue flow-control device provides a single Empty flag output, EF.
See Figure 46, SDR Read Queue Select, Read Operation for details of the
When multi-queue devices are connected in Expansion configuration, the EF
This connection of flag outputs to create a single flag requires that the EF flag
When queues within a single device are selected for read operations, the EF
The multi-queue device places its EF flag output into High-Impedance based
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
FEBRUARY 11, 2009