2
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
IDT72V2101/72V2111 3.3V HIGH DENSITY CMOS
SUPERSYNC FIFOTM 262,144 x 9, 524,288 x 9
PIN CONFIGURATIONS
TQFP (PN64-1, order code: PF)
TOP VIEW
DESCRIPTION (CONTINUED)
NOTES:
1. DC = Don’t Care. Must be tied to GND or VCC, cannot be left open.
2. This pin may either be tied to ground or left open.
3. DNC = Do Not Connect.
TheinputportiscontrolledbyaWriteClock(WCLK)inputandaWriteEnable
(
WEN)input. DataiswrittenintotheFIFOoneveryrisingedgeofWCLKwhen
WEN is asserted. The output port is controlled by a Read Clock (RCLK) input
andReadEnable(
REN)input. DataisreadfromtheFIFOoneveryrisingedge
of RCLK when
REN is asserted. An Output Enable (OE) input is provided for
three-state control of the outputs.
The frequencies of both the RCLK and the WCLK signals may vary from
0 to fMAX with complete independence. There are no restrictions on the
frequency of the one clock input with respect to the other.
There are two possible timing modes of operation with these devices:
IDT Standard mode and First Word Fall Through (FWFT) mode.
In IDT Standard mode, the first word written to an empty FIFO will not
appear on the data output lines unless a specific read operation is
performed. A read operation, which consists of activating
RENandenablinga
risingRCLKedge,willshiftthewordfrominternalmemorytothedataoutputlines.
In FWFT mode, the first word written to an empty FIFO is clocked directly
to the data output lines after three transitions of the RCLK signal. A
REN
does not have to be asserted for accessing the first word. However,
subsequent words written to the FIFO do require a LOW on
REN for access.
The state of the FWFT/SI input during Master Reset determines the timing
mode in use.
For applications requiring more data storage capacity than a single FIFO
can provide, the FWFT timing mode permits depth expansion by chaining
FIFOs in series (i.e. the data outputs of one FIFO are connected to the
corresponding data inputs of the next). No external logic is required.
These FIFOs have five flag pins,
EF/OR (Empty Flag or Output Ready),
FF/IR (Full Flag or Input Ready), HF (Half-full Flag), PAE (Programmable
Almost-Empty flag) and
PAF (Programmable Almost-Full flag). The EF and
FFfunctionsareselectedinIDTStandardmode. TheIRandORfunctionsare
selected in FWFT mode.
HF, PAE and PAF are always available for use,
irrespective of timing mode.
PIN 1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
WEN
SEN
DC(1)
VCC
GND(2)
D8
D7
64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
DNC(3)
GND
DNC(3)
VCC
DNC(3)
GND
DNC(3)
Q8
Q7
Q6
GND
WCLK
PRS
MRS
LD
FWFT/SI
GND
FF
/IR
PAF
HF
V
CC
PAE
EF
/OR
RCLK
REN
RT
OE
Q5
Q4
V
CC
Q3
Q2
GND
Q1
Q0
GND
D0
D1
D2
D3
D4
D5
D6
4669 drw 02