IDT72V3640/50/60/70/80/90/110 3.3V HIGH DENSITY SUPERSYNC II
TM
36-BIT FIFO
1,024 x 36, 2,048 x 36, 4,096 x 36, 8,192 x 36, 16,384 x 36, 32,768 x 36, 65,536 x 36, 131,072 x 36
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
TABLE 2
DEFAULT PROGRAMMABLE
FLAG OFFSETS
IDT72V3640, 72V3650
FSEL1
H
L
L
H
L
H
L
H
FSEL1
X
X
FSEL1
L
H
L
L
H
H
L
H
FSEL1
X
X
FSEL1
H
L
H
H
L
L
H
L
FSEL1
X
X
LD
L
L
L
L
H
H
H
H
LD
H
L
LD
H
L
L
L
L
H
H
H
LD
H
L
LD
L
L
L
H
H
H
H
L
LD
H
L
FSEL0
L
H
L
H
L
L
H
H
FSEL0
X
X
FSEL0
L
L
H
L
H
L
H
H
FSEL0
X
X
FSEL0
L
H
H
L
L
H
H
L
FSEL0
X
X
Offsets n,m
511
255
127
63
31
15
7
3
Program Mode
Serial
(3)
Parallel
(4)
Offsets n,m
1,023
511
255
127
63
31
15
7
Program Mode
Serial
(3)
Parallel
(4)
Offsets n,m
16,383
8,191
4,095
2,047
1,023
511
255
127
Program Mode
Serial
(3)
Parallel
(4)
IDT72V3660, 72V3670, 72V3680, 72V3690
PROGRAMMING FLAG OFFSETS
Full and Empty Flag offset values are user programmable. The IDT72V3640/
72V3650/72V3660/72V3670/72V3680/72V3690/72V36100/72V36110 have
internal registers for these offsets. There are eight default offset values selectable
during Master Reset. These offset values are shown in Table 2. Offset values
can also be programmed into the FIFO in one of two ways; serial or parallel
loading method. The selection of the loading method is done using the
LD
(Load)
pin. During Master Reset, the state of the
LD
input determines whether serial
or parallel flag offset programming is enabled. A HIGH on
LD
during Master
Reset selects serial loading of offset values. A LOW on
LD
during Master Reset
selects parallel loading of offset values.
In addition to loading offset values into the FIFO, it is also possible to read
the current offset values. Offset values can be read via the parallel output port
Q
0
-Qn, regardless of the programming mode selected (serial or parallel). It is
not possible to read the offset values in serial fashion.
Figure 3, Programmable Flag Offset Programming Sequence, summaries
the control pins and sequence for both serial and parallel programming modes.
For a more detailed description, see discussion that follows.
The offset registers may be programmed (and reprogrammed) any time after
Master Reset, regardless of whether serial or parallel programming has been
selected. Valid programming ranges are from 0 to D-1.
SYNCHRONOUS vs ASYNCHRONOUS PROGRAMMABLE FLAG TIM-
ING SELECTION
The IDT72V3640/72V3650/72V3660/72V3670/72V3680/72V3690/
72V36100/72V36110 can be configured during the Master Reset cycle with
either synchronous or asynchronous timing for
PAF
and
PAE
flags by use of
the PFM pin.
If synchronous
PAF/PAE
configuration is selected (PFM, HIGH during
MRS),
the PAF is asserted and updated on the rising edge of WCLK only and
not RCLK. Similarly,
PAE
is asserted and updated on the rising edge of RCLK
only and not WCLK. For detail timing diagrams, see Figure 17 for synchronous
PAF
timing and Figure 18 for synchronous
PAE
timing.
If asynchronous
PAF/PAE
configuration is selected (PFM, LOW during
MRS),
the PAF is asserted LOW on the LOW-to-HIGH transition of WCLK and
PAF
is reset to HIGH on the LOW-to-HIGH transition of RCLK. Similarly,
PAE
is asserted LOW on the LOW-to-HIGH transition of RCLK.
PAE
is reset to HIGH
on the LOW-to-HIGH transition of WCLK. For detail timing diagrams, see Figure
19 for asynchronous
PAF
timing and Figure 20 for asynchronous
PAE
timing.
IDT72V36100, 72V36110
NOTES:
1. n = empty offset for
PAE.
2. m = full offset for
PAF.
3. As well as selecting serial programming mode, one of the default values will also
be loaded depending on the state of FSEL0 & FSEL1.
4. As well as selecting parallel programming mode, one of the default values will
also be loaded depending on the state of FSEL0 & FSEL1.
10
IDT [ INTEGRATED DEVICE TECHNOLOGY ]
