IDT7202 IDT [Integrated Device Technology], IDT7202 Datasheet - Page 12

• Manufacturer Part Number: IDT7202
• Description: CMOS ASYNCHRONOUS FIFO WITH RETRANSMIT 1K x 9, 2K x 9, 4K x 9
• Manufacturer: IDT [Integrated Device Technology]

IDT72021, IDT72031, IDT72041
CMOS ASYNCHRONOUS FIFO WITH RETRANSMIT 1K x 9, 2K x 9, 4K x 9
permits the writing of a single word of data immediately after
reading one word of data from a full FIFO. The
the
to be asserted again in anticipation of a new data word. On the
rising edge of
TRUTH TABLES
NOTE:
1. IDT only guarantees depth expansion with identical IDT part numbers and speed.
TABLE I—RESET AND RETRANSMIT
Single Device Configuration/Width Expansion Mode
NOTE:
1. Pointer will increment if flag is HIGH.
TABLE II—RESET AND FIRST LOAD TRUTH TABLE
Depth Expansion/Compound Expansion Mode
NOTE:
1.
Reset
Retransmit
Read/Write
Reset First Device
Reset All Other Devices
Read/Write
In the write flow-through mode (Figure 18), the FIFO
XI
XI
FF
is connected to
= Expansion Input,
to be deasserted but the
Mode
Mode
W
, the new word is loaded in the FIFO. The
FULL
XO
RS
W
D
of previous device. See Figure 15.
HF
= Half-Full Flag Output,
RS
RS
0
1
1
0
0
1
Figure 15. Block Diagram of 3K/6K/12K x 9 FIFO Memory (Depth Expansion)
9
W
line, being LOW causes it
Inputs
Inputs
RT
FL
X
X
0
1
0
1
AEF
= Almost Empty/Almost Full Flag.
R
9
9
(1)
(1)
(1)
RS
XI
XI
0
0
0
line causes
9
= Reset Input
FF
FF
FF
031/041
031/041
031/041
Location Zero
Location Zero
Increment
Read Pointer
Location Zero
Location Zero
72021/
72021/
72021/
Read Pointer
IDT
IDT
IDT
W
5.09
XO
XI
XO
XI
XO
XI
FL
line must be toggled when
in the FIFO and to increment the write pointer.
FIFOs on Full and Empty Boundary Conditions” and Tech
Note 6: “Designing with FIFOs”.
X
/
RT
(1)
For additional information refer to Tech Note 8: “Operating
Internal Status
Internal Status
= First Load/Retransmit,
EF
FL
EF
FL
EF
FL
MILITARY AND COMMERCIAL TEMPERATURE RANGES
Location Zero
Unchanged
Increment
Write Pointer
Location Zero
Location Zero
Write Pointer
9
X
(1)
EF
FF
= Empty Flag Output,
is not asserted to write new data
2677 drw 18
EF
X
X
0
R
Q
V
EMPTY
EF
CC
X
0
0
Outputs
Outputs
FF
X
1
X
FF
= Flag Full Output,
HF
X
X
1
FF
X
1
1
2677 tbl 11
2677 tbl 12
AEF
12
X
X
0