Asynchronous FIFO V1.0.3
Table 4 shows the approximate number of slices per bit for
a distributed ram based FIFO. Multiply this number by the
data width to determine the total slice count for the mem-
ory. Control logic resource utilization is a function of the
required addressing width N (N = log2(fifo_depth+1) and
the optional features enabled. The slice count calculation
varies slightly depending on N being odd or even.
For N even, slice count is:
-
-
-
-
-
(N * 3.5) + 6
+(N * 0.5) + 2
+(N * 2.0) + 1
+(1)
+(1)
(Base)
(per almost flag)
(per data count)
(for write handshaking)
(for read handshaking))
For N odd, slice count is:
-
Table 3: Default Values and XCO File Values
Parameter
component_name
XCO File values
ASCII text starting with a letter and based
upon the following character set: a..z, 0..9,
and _
Keyword block, anything else generates
LUT RAM
Integer in the range 1 to 64
Integer in the range 15 to 4095. Must be
equal to (2^N-1;, N = 4 to 12)
One of the following keywords: true, false
One of the following keywords: true, false
One of the following keywords: true, false
One of the following keywords: active_high,
active_low
One of the following keywords: true, false
One of the following keywords: active_high,
active_low
One of the following keywords: true, false
One of the following keywords: active_high,
active_low
One of the following keywords: true, false
One of the following keywords: active_high,
active_low
One of the following keywords: true, false
Integer in the range 1 to N, where N is deter-
mined by the fifo_depth
One of the following keywords: true, false
Integer in the range 1 to N, where N is deter-
mined by the fifo_depth
One of the following keywords: true, false
Default GUI Setting
blank
block
16
63
false
false
false
active_high
false
active_high
false
active_high
false
active_high
false
2
false
2
false
(N * 3.5) + 7.5
(Base)
memory_type
input_data_wiidth
fifo_depth
almost_full_flag
almost_empty_flag
write_acknowledge_flag
write_acknowledge_sense
write_error_flag
write_error_sense
read_acknowledge_flag
read_acknowledge_sense
read_error_flag
read_error_sense
write_count
write_count_width
read_count
read_count_width
create_rpm
6
December 17, 1999
XILINX [ XILINX, INC ]
