5
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
IDT72V3640/50/60/70/80/90 3.3V HIGH DENSITY SUPERSYNC IITM 36-BIT FIFO
1,024 x 36, 2,048 x 36, 4,096 x 36, 8,192 x 36, 16,384 x 36 and 32,768 x 36
OCTOBER 22, 2008
BM
IW
OW
Write Port Width
Read Port Width
L
x36
H
L
x36
x18
H
L
H
x36
x9
H
L
x18
x36
H
x9
x36
TABLE 1 — BUS-MATCHING CONFIGURATION MODES
If asynchronous
PAE/PAF configuration is selected, the PAE is asserted
LOWontheLOW-to-HIGHtransitionofRCLK.
PAEisresettoHIGHontheLOW-
to-HIGH transition of WCLK. Similarly, the
PAFisassertedLOWontheLOW-
to-HIGH transition of WCLK and
PAF is reset to HIGH on the LOW-to-HIGH
transition of RCLK.
Ifsynchronous
PAE/PAFconfigurationisselected,thePAEisassertedand
updated on the rising edge of RCLK only and not WCLK. Similarly,
PAF is
assertedandupdatedontherisingedgeofWCLKonlyandnotRCLK.Themode
desiredisconfiguredduringMasterResetbythestateoftheProgrammableFlag
Mode (PFM) pin.
The Retransmit function allows data to be reread from the FIFO more than
once. A LOW on the
RTinputduringarisingRCLKedgeinitiatesaretransmit
operation by setting the read pointer to the first location of the memory array.
A zero-latency retransmit timing mode can be selected using the Retransmit
timing Mode pin (RM). During Master Reset, a LOW on RM will select zero
latency retransmit. A HIGH on RM during Master Reset will select normal
latency.
If zero latency retransmit operation is selected, the first data word to be
retransmittedwillbeplacedontheoutputregisterwithrespecttothesameRCLK
edge that initiated the retransmit based on RT being LOW.
Refer to Figure 11 and 12 for Retransmit Timingwith normal latency. Refer
to Figure 13 and 14 for Zero Latency Retransmit Timing.
The device can be configured with different input and output bus widths as
shown in Table 1.
A Big-Endian/Little-Endian data word format is provided. This function is
usefulwhendataiswrittenintotheFIFOinlongwordformat(x36/x18)andread
NOTE:
1. Pin status during Master Reset.
out of the FIFO in small word (x18/x9) format. If Big-Endian mode is selected,
then the most significant byte (word) of the long word written into the FIFO will
bereadoutoftheFIFOfirst,followedbytheleastsignificantbyte.IfLittle-Endian
formatisselected,thentheleastsignificantbyteofthelongwordwrittenintothe
FIFOwillbereadoutfirst,followedbythemostsignificantbyte.Themodedesired
is configured during master reset by the state of the Big-Endian (
BE)pin.See
Figure 4 for Bus-Matching Byte Arrangement.
The Interspersed/Non-Interspersed Parity (IP) bit function allows the user
to select the parity bit in the word loaded into the parallel port (D0-Dn) when
programming the flag offsets. If Interspersed Parity mode is selected, then the
FIFO will assume that the parity bit is located in bit positions D8, D17, D26 and
D35 during the parallel programming of the flag offsets. If Non-Interspersed
Parity mode is selected, then D8, D17 and D26 are assumed to be valid bits
and D32, D33, D34 and D35 are ignored. IP mode is selected during Master
Reset by the state of the IP input pin. Interspersed Parity control only has an
effectduringparallelprogrammingoftheoffsetregisters.Itdoesnoteffectthedata
written to and read from the FIFO.
A JTAG test port is provided, here the FIFO has fully functional Boundary
Scan feature, compliant with IEEE 1149.1 Standard Test Access Port and
Boundary Scan Architecture.
If, at any time, the FIFO is not actively performing an operation, the chip will
automatically power down. Once in the power down state, the standby supply
currentconsumptionisminimized. Initiatinganyoperation(byactivatingcontrol
inputs) will immediately take the device out of the power down state.
The IDT72V3640/72V3650/72V3660/72V3670/72V3680/72V3690 are
fabricated using IDT’s high speed submicron CMOS technology.