LH540235M-20 SHARP [Sharp Electrionic Components], LH540235M-20 Datasheet - Page 10

• Manufacturer Part Number: LH540235M-20
• Description: 2048 x 18 / 4096 x 18 Synchronous FIFOs
• Manufacturer: SHARP [Sharp Electrionic Components]

NOTE:
1. FL/ RT may be grounded if the Retransmit facility is not being used.
LH540235/45
DESCRIPTION OF SIGNALS AND OPERATING SEQUENCES
NOTES:
1. In IDT-compatible cascading, a reset operation forces WXO/HF and RXO/ EF
2. The terms ‘master’ and ‘slave’ refer to IDT-compatible cascading. In pipelined cascading
3. Once grouping mode has been determined during a reset operation, FL/RT then may go HIGH to activate a retransmit operation.
4. EMODE must be asserted for access to the Control Register to be enabled. Also, FIFOs being used in a pipelined-cascading
5. Setup-time and recovery-time specifications apply during a reset operation.
BOLD ITALIC = Enhanced Operating Mode
10
EMODE
HIGH for the (n + 1)st FIFO.
configuration should be in Interlocked Paralleled mode.
I/O
H
H
O
O
H
H
H
H
L
L
I
I
I
1
1
WXI / WEN
WXO/HF
RXI/ REN
RXO /EF
FL/ RT
WXI/ WEN
PIN
H
H
H
L
L
L
X
X
2
2
2
2
RXI/ REN
From WXO ((n-1)st FIFO)
To WXI ((n+1)st FIFO)
From RXO ((n-1)st FIFO)
To RXI ((n+1)st FIFO)
Grounded (Logic LOW)
H
H
H
X
X
DEPTH-CASCADED
L
L
L
2
MASTER
Table 2. Expansion-Pin Usage According to
FL/ RT
H
H
Table 1. Grouping-Mode Determination
H
L
X
X
L
L
3
3
3
3
IDT-COMPATIBLE OPERATING MODE
During a Reset Operation
Cascaded
Slave
Cascaded
Master
(Reserved)
(Reserved)
(Not
Allowed
During
Reset)
Standalone
(Not
Allowed
During
Reset)
Interlocked
Paralleled
MODE
Grouping Mode
From WXO ((n-1)st FIFO)
To WXI ((n+1)st FIFO)
From RXO ((n-1)st FIFO)
To RXI ((n+1)st FIFO)
Logic HIGH
2
2
DEPTH-CASCADED
4
SLAVE
WXO/HF
USAGE
WXO
WXO
(HF)
HF
(HF)
HF
–
–
2
HIGH for the nth FIFO, thus forcing WXI/ WEN
5
WXI/ WEN
WXI
WXI
(none)
(none)
(WEN
WEN
2048 x 18/4096 x 18 Synchronous FIFOs
USAGE
4
, there is no such distinction.
–
–
Grounded
Becomes HF
Grounded
Unused
Becomes RT
STANDALONE
2
2
)
2
RXI/ REN
(none)
(none)
RXI
RXI
(REN
REN
USAGE
–
–
1
2
2
)
2
From FF (other FIFO)
Becomes HF
From EF (other FIFO)
Becomes EF
Becomes RT
OPERATING MODE
USAGE
INTERLOCKED
FL
FL
(RT)
RT
(RT)
RT
PARALLELED
FL/ RT
ENHANCED
–
–
2
and RXI/ REN
2
1
RXO /EF
USAGE
RXO
RXO
(none)
(none)
(EF
EF
–
–
2
2
)
2
2