IDT72P51359L6BB8 IDT, Integrated Device Technology Inc, IDT72P51359L6BB8 Datasheet - Page 44

• Manufacturer Part Number: IDT72P51359L6BB8
• Description: IC FLOW CTRL 36BIT 256-BGA
• Manufacturer: IDT, Integrated Device Technology Inc

Specifications of IDT72P51359L6BB8

• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 72P51359L6BB8

write port may experience a change of its internal almost empty flag status based
on write operations. The multi-queue flow-control device also provides a
duplicate of the PAE flag on the PAE[7:0] flag bus, this will be discussed in detail
in a later section of the data sheet.
PAFn - DIRECT BUS
mode. In direct mode the user can address the status word of queues they
require and it will be placed on to the PAFn bus. For example, consider the
operation of the PAFn bus when 26 queues have been setup. To output status
of the first status word, Queue[0:7] the WRADD bus is used in conjunction with
the FSTR (PAF flag strobe) input and WCLK. The address present on the 4
least significant bits of the WRADD bus with FSTR HIGH will be selected as the
status word address on a rising edge of WCLK. To address status word 0,
Queue[0:7] the WRADD bus should be loaded with “0010000”, the PAFn bus
will change status to show the new status word selected 1 WCLK cycle after status
word selection. PAFn[0:7] gets status of queues, Queue[0:7] respectively.
PAFn[0:7] gets status of queues, Queue[8:15] respectively. To address the 2nd
status word, Queue[16:23], the WRADD address is “00100010”. PAF[0:7] gets
status of queues, Queue[16:23] respectively. To address the 3rd status word,
Queue[24:31], the WRADD address is “00100011”. PAF[0:1] gets status of
queues, Queue[24:25] respectively. Remember, only 26 queues were setup,
so when status word 4 is selected the unused outputs PAF[2:7] will be don't care
states.
queue ‘x’ on the same cycle as a status word switch which will include the queue
‘x’, then there may be an extra WCLK cycle delay before that queues status is
correctly shown on the respective output of the PAFn bus. However, the active
PAF flag will show correct status at all times.
word on the PAFn bus can change every WCLK cycle. Also, data present on
the input bus, Din, can be written into a Queue on the same WCLK rising edge
that a status word is being selected, the only restriction being that a write queue
selection and PAFn status word selection cannot be made on the same cycle.
output on PAF[0:7] constantly.
device the PAFn busses of all devices are connected together, when switching
between status words of different devices the user must utilize the 1-3 most
significant bits of the WRADD address bus (as well as the 2 LSB’s). These 1-
3 MSb’s correspond to the device ID inputs, which are the static inputs, ID0, ID1
& ID2.
timing information. Also refer to Table 4, Write Address Bus, WRADD.
PAFn – POLLED BUS
mode. In polled mode the PAFn bus only cycles through the number of status
words required to display the status of the number of queues that have been
setup in the part. Every rising edge of the WCLK causes the next status word
to be loaded on the PAFn bus. The device configured as the master (MAST
input tied HIGH), will take control of the PAFn after MRS goes LOW. For the whole
WCLK cycle that the first status word is on PAFn the FSYNC (PAFn bus sync)
output will be HIGH, for all other status words, this FSYNC output will be LOW.
This FSYNC output provides the user with a mark with which they can
IDT72P51339/72P51349/72P51359/72P51369 1.8V, MQ FLOW-CONTROL DEVICES
(8 QUEUES) 36 BIT WIDE CONFIGURATION 589, 824, 1,179,648, 2,359,296, and 4,718,592
See Figures 25 and 26 for Almost Empty flag timing and queue switching.
If FM is LOW at master reset then the PAFn bus operates in Direct (addressed)
To address status word 1, Queue[8:15], the WRADD address is “00100001”.
Note, that if a read or write operation is occurring to a specific queue, say
Status words can be selected on consecutive clock cycles, that is the status
If 8 or less queues are setup then queues, Queue[0:7] have their PAF status
When the multi-queue devices are connected in expansion of more than one
Please refer to Figure 63 PAF n - Direct Mode Status Word Selection for
If FM is HIGH at master reset then the PAFn bus operates in Polled (looped)
44
synchronize to the PAFn bus, FSYNC is always HIGH for the WCLK cycle that
the first status word of a device is present on the PAFn bus.
will be set as the Master (ID = '000'), MAST input tied HIGH, all other devices
will have MAST tied LOW. The master device is the first device to take control
of the PAFn bus and will place its first status word on the bus on the rising edge
of WCLK. For the next n WCLK cycles (n= number of queues divided by 8 with
n being increased by one for any remainder) the master device will maintain
control of the PAFn bus and cycle its status words through it, all other devices
hold their PAFn outputs in High-Impedance. When the master device has cycled
all of its status words it passes a token to the next device in the chain and that
device assumes control of the PAFn bus and then cycles its status words and
so on, the PAFn bus control token being passed on from device to device. This
token passing is done via the FXO outputs and FXI inputs of the devices (“PAF
Expansion Out” and “PAF Expansion In”). The FXO output of the master device
connects to the FXI of the second device in the chain and the FXO of the second
connects to the FXI of the third and so on. The final device in a chain has its FXO
connected to the FXI of the first device, so that once the PAFn bus has cycled
through all status words of all devices, control of the PAFn will pass to the master
device again and so on. The FSYNC of each respective device will operate
independently and simply indicate when that respective device has taken control
of the bus and is placing its first status word on to the PAFn bus.
the FXO output of the same device. In single device mode a token is still required
to be passed into the device for accessing the PAFn bus.
PAEn/PRn FLAG BUS OPERATION
trol device can be configured for up to 8 queues, each queue having its own
almost empty/ packet ready status. An active queue has its flag status output to
the discrete flags, OR, PAE and PR, on the read port. Queues that are not
selected for a read operation can have their PAE/PR status monitored via the
PAEn/PRn bus. The PAEn/PRn 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).
PAEn/PRn - DIRECT BUS
(addressed) mode. In direct mode the user can address the status word of
queues they require to be placed on to the PAEn/PRn bus. For example,
consider the operation of the PAEn/PRn bus when 26 queues have been setup.
To output status of the first status word, Queue[0:7] the RDADD bus is used in
conjunction with the ESTR (PAE/PR flag strobe) input and RCLK. The address
present on the 2 least significant bits of the RDADD bus with ESTR HIGH will
be selected as the status word address on a rising edge of RCLK. So to address
status word 1, Queue[0:7] the RDADD bus should be loaded with “xxxx0000”,
the PAEn/PRn bus will change status to show the new status word selected 1
RCLK cycle after status word selection. PAEn[0:7] gets status of queues,
Queue[0:7] respectively.
“xxxx0001”. PAEn[0:7] gets status of queues, Queue[8:15] respectively. To
When devices are connected in expansion configuration, only one device
When operating in single device mode the FXI input must be connected to
Please refer to Figure 66, PAF n Bus – Polled Mode for timing information.
The IDT72P51339/72P51349/72P51359/72P51369 multi-queue flow-con-
If FM is LOW at master reset then the PAEn/PRn bus operates in Direct
To address the second status word, Queue[8:15], the RDADD address is
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
AUGUST 4, 2005