7
IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FLOW-CONTROL DEVICES
(4 QUEUES) 18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
FSYNC PAFn Bus Sync LVTTL FSYNC is an output from the multi-queue device that provides a synchronizing pulse for the PAFn bus
(R3) OUTPUT during Polled operation of the PAFn bus. During Polled operation each quadrant of queue status flags
is loaded on to the PAFn bus outputs sequentially based on WCLK. The first WCLK rising edge loads
device1 on to the PAFn bus outputs, the second WCLK rising edge loads device 2 and so on. During the
WCLK cycle that a selected device is placed on to the PAFn bus, the FSYNC output will be HIGH.
FXI PAFn Bus LVTTL The FXI input is used when multi-queue devices are connected in expansion mode and Polled PAFn
(T2) Expansion In INPUT bus operation has been selected . FXI of device ‘N’ connects directly to FXO of device ‘N-1’. The FXI
receives a token from the previous device in a chain. In single device mode the FXI input must be tied
LOW if the PAFn bus is operated in direct mode. If the PAFn bus is operated in polled mode the FXI input
must be connected to the FXO output of the same device. In expansion mode the FXI of the first device
should be tied LOW, when direct mode is selected.
FXO PAFn Bus LVTTL FXO is an output that is used when multi-queue devices are connected in expansion mode and Polled
(T3) Expansion Out OUTPUT PAFn bus operation has been selected . FXO of device ‘N’ connects directly to FXI of device ‘N+1’. This
pin pulses HIGH when device N places its PAF status on to the PAFn bus with respect to WCLK. This pulse
(token) is then passed on to the next device in the chain ‘N+1’ and on the next WCLK rising edge the first
quadrant of device N+1 will be loaded on to the PAFn bus. This continues through the chain and FXO
of the last device is then looped back to FXI of the first device. The FSYNC output of each device in the
chain provides synchronization to the user of this looping event.
ID[2:0]
(1)
Device ID Pins LVTTL For the 4Q multi-queue device the WRADD address bus is 5 bits and RDADD address bus is 6 bits wide.
(ID2-C9 INPUT When a queue selection takes place the 3 MSb’s of this address bus are used to address the specific device
ID1-A10 (the LSb’s are used to address the queue within that device). During write/read operations the 3 MSb’s
ID0-B10) of the address are compared to the device ID pins. The first device in a chain of multi-queue’s (connected
in expansion mode), may be setup as ‘000’, the second as ‘001’ and so on through to device 8 which is
‘111’, however the ID does not have to match the device order. In single device mode these pins should
be setup as ‘000’ and the 3 MSb’s of the WRADD and RDADD address busses should be tied LOW. The
ID[2:0] inputs setup a respective devices ID during master reset. These ID pins must not toggle during
any device operation. Note, the device selected as the ‘Master’ does not have to have the ID of ‘000’.
IW
(1)
Input Width LVTTL IW selects the bus width for the data input bus. If IW is LOW during a Master Reset then the bus width
(L15) INPUT is x18, if HIGH then it is x9.
MAST
(1)
Master Device LVTTL The state of this input at Master Reset determines whether a given device (within a chain of devices), is the
(K15) INPUT Master device or a Slave. If this pin is HIGH, the device is the master, if it is LOW then it is a Slave. The
master device is the first to take control of all outputs after a master reset, all slave devices go to
High-Impedance, preventing bus contention. If a multi-queue device is being used in single device mode,
this pin must be set HIGH.
MRS Master Reset LVTTL A master reset is performed by taking MRS from HIGH to LOW, to HIGH. Device programming is required
(T9) INPUT after master reset.
OE Output Enable LVTTL The Output enable signal is an Asynchronous signal used to provide three-state control of the multi-queue
(M14) INPUT data output bus, Qout. If a device has been configured as a “Master” device, the Qout data outputs will
be in a Low Impedance condition if the OE input is LOW. If OE is HIGH then the Qout data outputs will be
in High Impedance. If a device is configured a “Slave” device, then the Qout data outputs will always be
in High Impedance until that device has been selected on the Read Port, at which point OE provides three-
state of that respective device.
OV Output Valid Flag LVTTL This output flag provides output valid status for the data word present on the multi-queue flow-control device
(P9) OUTPUT data output port, Qout. This flag is therefore, 2-stage delayed to match the data output path delay. That
is, there is a 2 RCLK cycle delay from the time a given queue is selected for reads, to the time the OV flag
represents the data in that respective queue. When a selected queue on the read port is read to empty,
the OV flag will go HIGH, indicating that data on the output bus is not valid. The OV flag also has High-
Impedance capability, required when multiple devices are used and the OV flags are tied together.
OW
(1)
Output Width LVTTL OW selects the bus width for the data output bus. If OW is LOW during a Master Reset then the bus width
(L16) INPUT is x18, if HIGH then it is x9.
PIN DESCRIPTIONS (CONTINUED)
Symbol & Name I/O TYPE Description
Pin No.
8
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FLOW-CONTROL DEVICES
(4 QUEUES) 18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits
PAE Programmable LVTTL This pin provides the Almost-Empty flag status for the queue that has been selected on the output port
(P10) Almost-Empty Flag OUTPUT for read operations, (selected via RCLK, RDADD and RADEN). This pin is LOW when the selected
queue is almost-empty. This flag output may be duplicated on one of the PAEn bus lines. This flag is
synchronized to RCLK.
PAEn Programmable LVTTL On the 4Q device the PAEn bus is 4 bits wide. This output bus provides PAE status of all 4 queues, within a
(PAE3-P13 Almost-Empty OUTPUT selected device. During queue read/write operations these outputs provide programmable empty flag
PAE2-R13 Flag Bus status in either director polled mode. The mode of flag operation is determined during master reset via
PAE1-T13 the state of the FM input. This flag bus is capable of High-Impedance state, this is important during expansion
PAE0-T14) of multi-queue devices. During direct operation the PAEn bus is updated to show the PAE status of queues
within a selected device. Selection is made using RCLK, ESTR and Flag Bus RDADD. During Polled
operation the PAEn bus is loaded with the PAE status of multi-queue flow-control devices sequentially
based on the rising edge of RCLK.
PAF Programmable LVTTL This pin provides the Almost-Full flag status for the queue that has been selected on the input port for
(R8) Almost-Full Flag OUTPUT write operations, (selected via WCLK, WRADD and WADEN). This pin is LOW when the selected queue
is almost-full. This flag output may be duplicated on one of the PAFn bus lines. This flag is synchronized
to WCLK.
PAFn Programmable LVTTL On the 4Q device the PAFn bus is 4 bits wide. This output bus provides PAF status of all 4 queues, within a
(PAE3-P5 Almost-Full OUTPUT selected device. During queue read/write operations these outputs provide programmable full flag status,
PAE2-R5 Flag Bus in either direct or polled mode. The mode of flag operation is determined during master reset via the state
PAE1-T5 of the FM input. This flag bus is capable of High-Impedance state, this is important during expansion of
PAE0-T4) multi-queue devices. During direct operation the PAFn bus is updated to show the PAF status of a queues
within a selected device. Selection is made using WCLK, FSTR, WRADD and WADEN. During Polled
operation the PAFn bus is loaded with the PAF status of multi-queue flow-control devices sequentially
based on the rising edge of WCLK.
PRS Partial Reset LVTTL A Partial Reset can be performed on a single queue selected within the multi-queue device. Before a Partial
(T8) INPUT Reset can be performed on a queue, that queue must be selected on both the write port and read port
2 clock cycles before the reset is performed. A Partial Reset is then performed by taking PRS LOW for
one WCLK cycle and one RCLK cycle. The Partial Reset will only reset the read and write pointers to
the first memory location, none of the devices configuration will be changed.
Q[17:0] Data Output Bus LVTTL These are the 18 data output pins. Data is read out of the device via these output pins on the rising edge
Qout (See Pin OUTPUT of RCLK provided that REN is LOW, OE is LOW and the queue is selected. Due to bus matching not
table for details) all outputs may be used, any unused outputs should not be connected.
RADEN Read Address LVTTL The RADEN input is used in conjunction with RCLK and the RDADD address bus to select a queue to
(R14) Enable INPUT be read from. A queue addressed via the RDADD bus is selected on the rising edge of RCLK provided
that RADEN is HIGH. RADEN should be asserted (HIGH) only during a queue change cycle(s). RADEN
should not be permanently tied HIGH. RADEN cannot be HIGH for the same RCLK cycle as ESTR.
Note, that a read queue selection cannot be made, (RADEN must NOT go active) until programming of
the part has been completed and SENO has gone LOW.
RCLK Read Clock LVTTL When enabled by REN, the rising edge of RCLK reads data from the selected queue via the output bus
(T10) INPUT Qout. The queue to be read is selected via the RDADD address bus and a rising edge of RCLK while
RADEN is HIGH. A rising edge of RCLK in conjunction with ESTR and RDADD will also select the device
to be placed on the PAEn bus during direct flag operation. During polled flag operation the PAEn bus is
cycled with respect to RCLK and the ESYNC signal is synchronized to RCLK. The PAE and OV outputs
are all synchronized to RCLK. During device expansion the EXO and EXI signals are based on RCLK.
RCLK must be continuous and free-running.
RDADD Read Address Bus LVTTL For the 4Q device the RDADD bus is 6 bits. The RDADD bus is a dual purpose address bus. The first
[5:0] INPUT function of RDADD is to select a queue to be read from. The least significant 2 bits of the bus, RDADD[1:0]
(See next page are used to address 1 of 4 possible queues within a multi-queue device. Address pin, RDADD[2] provides
for details) the user with a Null-Q address. If the user does not wish to address one of the 4 queues, a Null-Q can
be addressed using this pin. The Null-Q operation is discussed in more detail later. The most significant
3 bits, RDADD[5:3] are used to select 1 of 8 possible multi-queue devices that may be connected in
expansion mode. These 3 MSB’s will address a device with the matching ID code. The address present
PIN DESCRIPTIONS (CONTINUED)
Symbol & Name I/O TYPE Description
Pin No.
9
IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FLOW-CONTROL DEVICES
(4 QUEUES) 18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
RDADD Read Address Bus LVTTL on the RDADD bus will be selected on a rising edge of RCLK provided that RADEN is HIGH, (note, that
[5:0] INPUT data can be placed on to the Qout bus, read from the previously selected queue on this RCLK edge).
(Continued) On the next rising RCLK edge after a read queue select, a data word from the previous queue will be
(RDADD5-P16 placed onto the outputs, Qout, regardless of the REN input. Two RCLK rising edges after read queue
RDADD4-P15 select, data will be placed on to the Qout outputs from the newly selected queue, regardless of REN due
RDADD3-P14 to the first word fall through effect.
RDADD2-N14 The second function of the RDADD bus is to select the device of queues to be loaded on to the PAEn
RDADD1-M16 bus during strobed flag mode. The most significant 3 bits, RDADD[5:3] are again used to select 1 of 8
RDADD0-M15) possible multi-queue devices that may be connected in expansion mode. Address bits RDADD[2:0] are
don’t care during device selection. The device address present on the RDADD bus will be selected on the
rising edge of RCLK provided that ESTR is HIGH, (note, that data can be placed on to the Qout bus, read
from the previously selected queue on this RCLK edge). Please refer to Table 2 for details on RDADD bus.
REN Read Enable LVTTL The REN input enables read operations from a selected queue based on a rising edge of RCLK. A
(T11) INPUT queue to be read from can be selected via RCLK, RADEN and the RDADD address bus regardless
of the state of REN. Data from a newly selected queue will be available on the Qout output bus on the second
RCLK cycle after queue selection regardless of REN due to the FWFT operation. A read enable is not
required to cycle the PAEn bus (in polled mode) or to select the device , (in direct mode).
SCLK Serial Clock LVTTL If serial programming of the multi-queue device has been selected during master reset, the SCLK input
(N3) INPUT clocks the serial data through the multi-queue device. Data setup on the SI input is loaded into the device
on the rising edge of SCLK provided that SENI is enabled, LOW. When expansion of devices is performed
the SCLK of all devices should be connected to the same source.
SENI Serial Input Enable LVTTL During serial programming of a multi-queue device, data loaded onto the SI input will be clocked into the
(M2) INPUT part (via a rising edge of SCLK), provided the SENI input of that device is LOW. If multiple devices are
cascaded, the SENI input should be connected to the SENO output of the previous device. So when serial
loading of a given device is complete, its SENO output goes LOW, allowing the next device in the chain
to be programmed (SENO will follow SENI of a given device once that device is programmed). The SENI
input of the master device (or single device), should be controlled by the user.
SENO Serial Output LVTTL This output is used to indicate that serial programming or default programming of the multi-queue device
(M1) Enable OUTPUT has been completed. SENO follows SENI once programming of a device is complete. Therefore, SENO
will go LOW after programming provided SENI is LOW, once SENI is taken HIGH again, SENO will also
go HIGH. When the SENO output goes LOW, the device is ready to begin normal read/write operations.
If multiple devices are cascaded and serial programming of the devices will be used, the SENO output
should be connected to the SENI input of the next device in the chain. When serial programming of the
first device is complete, SENO will go LOW, thereby taking the SENI input of the next device LOW and
so on throughout the chain. When a given device in the chain is fully programmed the SENO output
essentially follows the SENI input. The user should monitor the SENO output of the final device in the chain.
When this output goes LOW, serial loading of all devices has been completed.
SI Serial In LVTTL During serial programming this pin is loaded with the serial data that will configure the multi-queue devices.
(L1) INPUT Data present on SI will be loaded on a rising edge of SCLK provided that SENI is LOW. In expansion
mode the serial data input is loaded into the first device in a chain. When that device is loaded and its SENO
has gone LOW, the data present on SI will be directly output to the SO output. The SO pin of the first device
connects to the SI pin of the second and so on. The multi-queue device setup registers are shift registers.
SO Serial Out LVTTL This output is used in expansion mode and allows serial data to be passed through devices in the chain
(M3) OUTPUT to complete programming of all devices. The SI of a device connects to SO of the previous device in the
chain. The SO of the final device in a chain should not be connected.
TCK
(2)
JTAG Clock LVTTL Clock input for JTAG function. One of four terminals required by IEEE Standard 1149.1-1990. Test
(A8) INPUT operations of the device are synchronous to TCK. Data from TMS and TDI are sampled on the rising edge
of TCK and outputs change on the falling edge of TCK. If the JTAG function is not used this signal needs
to be tied to GND.
TDI
(2)
JTAG Test Data LVTTL One of four terminals required by IEEE Standard 1149.1-1990. During the JTAG boundary scan
(B9) Input INPUT operation,test data serially loaded via the TDI on the rising edge of TCK to either the Instruction Register,
ID Register and Bypass Register. An internal pull-up resistor forces TDI HIGH if left unconnected.
PIN DESCRIPTIONS (CONTINUED)
Symbol & Name I/O TYPE Description
Pin No.

72V51253L6BB

Mfr. #:
Manufacturer:
IDT
Description:
FIFO X18 4Q 2M MULTI-QUE
Lifecycle:
New from this manufacturer.
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