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9
COMMERCIAL AND INDUSTRIAL TEMPERATURE RANGES
IDT72V295/72V2105 3.3V HIGH DENSITY CMOS
SUPERSYNC FIFOTM 131,072 x 18, 262,144 x 18
Figure 4. Programmable Flag Offset Programming Sequence
Figure 3. Offset Register Location and Default Values
17
0
007FH if LD is LOW at Master Reset,
03FFH if LD is HIGH at Master Reset
DEFAULT VALUE
FULL OFFSET (LSB) REGISTER
17
0
DEFAULT VALUE
007FH if LD is LOW at Master Reset,
03FFH if LD is HIGH at Master Reset
15
IDT72V295 (131,072 x 18-BIT)
16
15
16
EMPTY OFFSET (LSB) REGISTER
17
0
007FH if LD is LOW at Master Reset,
03FFH if LD is HIGH at Master Reset
FULL OFFSET (LSB) REGISTER
17
0
DEFAULT VALUE
007FH if LD is LOW at Master Reset,
03FFH if LD is HIGH at Master Reset
15
IDT72V2105 (262,144 x 18-BIT)
16
15
16
EMPTY OFFSET (LSB) REGISTER
17
DEFAULT
0H
0
1
17
0
21
17
0
21
17
0
1
EMPTY OFFSET
(MSB) REGISTER
DEFAULT
0H
FULL OFFSET
(MSB) REGISTER
DEFAULT
0H
EMPTY OFFSET
(MSB) REGISTER
DEFAULT
0H
FULL OFFSET
(MSB) REGISTER
4668 drw 06
WCLK
RCLK
X
XX
X
XX
4668 drw 07
LD
0
X
1
0
WEN
0
1
0
X
1
REN
1
0
1
X
0
1
X
SEN
1
X
0
No Operation
Write Memory
Read Memory
No Operation
Parallel write to registers:
Empty Offset (LSB)
Empty Offset (MSB)
Full Offset (LSB)
Full Offset (MSB)
Serial shift into registers:
34 bits for the 72V295
36 bits for the 72V2105
1 bit for each rising WCLK edge
Starting with Empty Offset (LSB)
Ending with Full Offset (MSB)
IDT72V295
IDT72V2105
Parallel read from registers:
Empty Offset (LSB)
Empty Offset (MSB)
Full Offset (LSB)
Full Offset (MSB)
NOTES:
1. The programming method can only be selected at Master Reset.
2. Parallel reading of the offset registers is always permitted regardless of which programming method has been selected.
3. The programming sequence applies to both IDT Standard and FWFT modes.