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IDT72132 Datasheet, PDF (5/13 Pages) Integrated Device Technology – CMOS SERIAL-TO-PARALLEL FIFO 2048 x 9 4096 x 9
IDT72132, IDT72142
CMOS SERIAL-TO-PARALLEL FIFO 2048 x 9 AND 4096 x 9
AC TEST CONDITIONS
Input Pulse Levels
Input Rise/Fall Times
Input Timing Reference Levels
Output Reference Levels
Output Load
GND to 3.0V
5ns
1.5V
1.5V
See Figure A
2752 tbl 08
COMMERCIAL TEMPERATURE RANGES
5V
D.U.T.
680Ω
1.1K
Ω
30pF*
FUNCTIONAL DESCRIPTION
2752 drw 03
or equivalent circuit
Figure A. Output Load
*Includies jig and scope capacitances
Serial Data Input
The serial data is input on the SI pin. The data is clocked
in on the rising edge of SICP providing the Full Flag (FF) is not
asserted. If the Full Flag is asserted then the next parallel data
word is inhibited from moving into the RAM array. NOTE:
SICP should not be clocked once the last bit of the last word
has been shifted in, as indicated by NW HIGH and FF LOW.
If it is, then the input data will be lost.
The serial word is shifted in Least Significant Bit first. Thus,
when the FIFO is read, the Least Significant Bit will come out
on Q0 and the second bit is on Q1 and so on. The serial word
width must be programmed by connecting the appropriate
Data Set line (D7, D8) to the NW input. The data set lines are
taps off a digital delay line. Selecting one of these taps
programs the width of the serial word to be written in.
Parallel Data Output
A read cycle is initiated on the falling edge of Read (R)
provided the Empty Flag is not set. The output data is
accessed on a first-in/first-out basis, independent of the
ongoing write operations. The data is available tA after the
falling edge of R and the output bus Q goes into high imped-
ance after R goes HIGH.
Alternately, the user can access the FIFO by keeping R
LOW and enabling data on the bus by asserting Output Enable
(OE). When R is LOW, the OE signal enables data on the
output bus. When R is LOW and OE is HIGH, the output bus
is three-stated. When R is HIGH, the output bus is disabled
irrespective of OE.
RS
SICP
R
AEF, EF
HF, FF
D7 ,D8
t RSDL
t RSC
t RS
t RSS
tRSS
tRSF1
tRSF2
tRSR
0
n-1
(1)
t PDI
NOTE:
1. Input bits are numbered 0 to n-1. D7 and D8 correspond to n=8 and n=9 respectively
Figure 1. Reset
2752 drw 04
5.36
5