lf3304 LOGIC Devices Incorporated, lf3304 Datasheet - Page 4

• Manufacturer Part Number: lf3304
• Description: Dual Line Buffer/fifo
• Manufacturer: LOGIC Devices Incorporated

DEVICES INCORPORATED
LOW.
Controls
LDA — RAM Array A Load
When LDA is LOW, data on AIN
is latched in the LF3304 on the rising
edge of WCLKA.
LDB — RAM Array B Load
When LDB is LOW, data on BIN
is latched in the LF3304 on the rising
edge of WCLKB.
WENA — Write Enable A
If WENA is LOW, data on AIN
written to the device on the rising edge
of WCLKA. When RAM Array A is
full, WENA is ignored.
RENA — Read Enable A
If RENA is LOW, data from RAM
Array A is read and presented on
AOUT
rising edge of RCLKA if the output
port is enabled. If RENA goes HIGH,
the last value loaded in the RAM
Array A output register will remain
unchanged. When RAM Array A is
empty, RENA is ignored.
WENB — Write Enable B
If WENB is LOW, data on BIN
is written to the device on the rising
edgle of WCLKB. When RAM Array B
is full, WENB is ignored.
RENB — Read Enable B
If RENB is LOW, data from RAM
Array B is read and presented on
BOUT
rising edge of RCLKB if the output port
is enabled. If RENB goes HIGH, the
last value loaded in the RAM Array B
output register will remain unchanged.
When RAM Array B is empty, RENB is
ignored.
11-0
11-0
after tD has elapsed from the
after t
D
has elapsed from the
11-0
11-0
11-0
11-0
is
RWA — Reset Write A
The write address pointer is reset to
the first physical location when RWA is
set LOW. After power up, the LF3304
requires a Reset Write for initialization
because the write address pointer is not
defined at that time.
RRA — Reset Read A
The read address pointer is reset to
the first physical location when RRA is
set LOW. After power up, the LF3304
requires a Reset Read for initialization
because the read address pointer is not
defined at that time.
RWB — Reset Write B
See RWA Description.
RRB — Reset Read B
See RRA description.
OEA — Output Enable A
When OEA is LOW, AOUT
enabled for output. When OEA is
HIGH, AOUT
impedence state. The flag outputs are
not affected by OEA.
OEB — Output Enable B
When OEB is LOW, BOUT
enabled for output. When OEB is
HIGH, BOUT
impedence state. The flag outputs are
not affected by OEB.
Outputs
AOUT
AOUT
output port.
BOUT
BOUT
output port.
FFA — Full Flag A
FFA goes LOW when RAM Array A is
11-0
11-0
11-0
11-0
— Data Output B
is the 12-bit registered data
— Data Output A
is the 12-bit registered data
11-0
11-0
is placed in a high-
is placed in a high-
4
11-0
11-0
is
is
full of data. When FFA is LOW, RAM
Array A can not be written to. The Full
Flag is synchronized to the rising edge
of WCLKA.
EFA — Empty Flag A
EFA goes LOW when the read pointer
is equal to the write pointer, indicating
that RAM Array A is empty. When
EFA is LOW, read operations can not
be performed. The Empty Flag is syn-
chronized to the rising edge of RCLKA.
FFB — Full Flag B
FFB goes LOW when RAM Array B is
full of data. When FFB is LOW, RAM
Array B can not be written to. The Full
Flag is synchronized to the rising edge of
WCLKB.
EFB — Empty Flag B
EFB goes LOW when the read pointer
is equal to the write pointer, indicating
that RAM Array B is empty. When
EFB is LOW, read operations can not
be performed. The Empty Flag is syn-
chronized to the rising edge of RCLKB.
PAFA — Programmable Almost-Full Flag
A
PAFA goes LOW when the write
pointer is (Full – N) locations ahead of
the read pointer. N is the value stored
in the PAFA register and has no default
value. PAFA is synchronized to the
rising edge of WCLKA.
PAEA — Programmable Almost-Empty
Flag A
PAEA goes HIGH when the write
pointer is (N + 1) location ahead of the
read pointer. N is the value stored in
the PAEA register and has no default
value. PAEA is synchronized to the
rising edge of RCLKA.
PAFB — Programmable Almost-Full Flag B
PAFB goes LOW
is (Full – N) locations ahead of the read
Video Imaging Products
Dual Line Buffer/FIFO
when
the write pointer
9/28/2005–LDS.3304-I
LF3304