Datasheet

SN74V263, SN74V273, SN74V283, SN74V293
8192 × 18, 16384 × 18, 32768 × 18, 65536 × 18
3.3-V CMOS FIRST-IN, FIRST-OUT MEMORIES
SCAS669D – JUNE 2001 – REVISED FEBRUARY 2003
21
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Table 3. Status Flags for Standard Mode
IW = OW = ×9 SN74V263 SN74V273 SN74V283 SN74V293
IW ≠ OW OR
IW = OW = ×18
SN74V263 SN74V273 SN74V283 SN74V293
FF PAF HF PAE EF
0 0 0 0 0 H H H L L
1 to n 1 to n 1 to n 1 to n 1 to n H H H L H
(n + 1) to 4096 (n + 1) to 8192 (n + 1) to 16384 (n + 1) to 32768 (n + 1) to 65536 H H H H H
Number of
Words
in FIFO
4097 to
[8192 – (m + 1)]
8193 to
[16384 – (m + 1)]
16385 to
[32768 – (m + 1)]
32769 to
[65536 – (m + 1)]
65537 to
[131072 –
(m + 1)]
H H L H H
(8192 – m) to
8191
(16384 – m) to
16383
(32768 – m) to
32767
(65536 – m) to
65535
(131072 – m) to
131071
H L L H H
8192 16384 32768 65536 131072 L L L H H
NOTE 1: See Table 2 for values for n, m.
Table 4. Status Flags for FWFT Mode
IW = OW = ×9 SN74V263 SN74V273 SN74V283 SN74V293
IW ≠ OW OR
IW = OW = ×18
SN74V263 SN74V273 SN74V283 SN74V293
IR PAF HF PAE OR
0 0 0 0 0 L H H L H
1 to (n + 1) 1 to (n + 1) 1 to (n + 1) 1 to (n + 1) 1 to (n + 1) L H H L L
N mber of
(n + 2) to 4097 (n + 2) to 8193 (n + 2) to 16385 (n + 2) to 32769 (n + 2) to 65537 L H H H L
N
u
mber
of
Words
in FIF
O
4098 to
[8193 – (m + 1)]
8194 to
[16385 – (m + 1)]
16386 to
[32769 – (m + 1)]
32770 to
[65537 – (m + 1)]
65538 to
[131073 – (m + 1)]
L H L H L
in
FIFO
(8193 – m) to
8192
(16385 – m) to
16384
(32769 – m) to
32768
(65537 – m) to
65536
(131073 – m) to
131072
L L L H L
8193 16385 32769 65537 131073 H L L H L
NOTES: 1. See Table 2 for values for n, m.
2. Number of words in FIFO = FIFO depth + output register