Achronix Speedster22i User Macro Guide - Manual (Page 138)

Memories BRAM80KFIFO
Speedster22i Macro Cell Library Achronix Semiconductor Proprietary PAGE 121
Parameters
Table 6-16: BRAM80KFIFO Parameters
Parameter Defined Values Default Value
sync_mode 1’b0
write_width 40
read_width 40
fwft 1’b0
en_out_reg 1’b1
reg_initval 40’h0
reg_srval 40’h0
reg_rstval 1’b1
regce_priority “rstreg”
wrrst_rstval 1’b1
wrrst_input_mode 2’b10
wrrst_sync_stages 2’b00
wrptr_sync_stages 2’b00
rdrst_rstval 1’b1
rdrst_input_mode 2’b10
rdrst_sync_stages 2’b00
rdptr_sync_stages 2’b00
wrcount_sync_mode 1’b1
rdcount_sync_mode 1’b1
afull_offset 17’h00004
aempty_offset 17’h00004
wren_polarity_sel 1’b1
rden_polarity_sel 1’b1
en_rd_when_empty 1’b0
en_wr_when_full 1’b0
sync_mode
The sync_mode parameter is used to bypass the synchronization circutry between the read
and write ports when both ports are connected to the same clock. If both the wrclk and rdclk
clock inputs are connected to the same clock without any phase difference between the rdclk
and wrclk inputs, the user may set the sync_mode parameter to 1’b1 to allow faster updates to
the status flags (empty, full, etc.). If the read and write clocks are connected to different clocks,
the synchronization circutry must be used and the sync_mode parameter must be set to 1’b0.
The default value of the sync_mode parameter is 1’b0.
write_width
The write_width parameter defines the width of the data input bus of the FIFO from one to
forty bits according to the allowed values defined in
Table 6‐16: BRAM80KFIFO Parameters .
Table 6‐17: FIFO write_width versus Maximum Write Depth defines the maximum depth of
the FIFO for each of the valid values of the write_width parameter. The default value of the
write_width parameter is 40’h0.
1’b0, 1’b1
1, 2, 4, 5, 8, 9, 10, 16, 18, 20, 32, 36, 40
1, 2, 4, 5, 8, 9, 10, 16, 18, 20, 32, 36, 40
1’b0, 1’b1
1’b0, 1’b1
40-bit hexadecimal number
40-bit hexadecimal number
1’b0, 1’b1
“rstreg”, “regce”
1’b0, 1’b1
2’b00, 2’b01, 2’b10, 2’b11
2’b00, 2’b01, 2’b10, 2’b11
2’b00, 2’b01, 2’b10, 2’b11
1’b0, 1’b1
2’b00, 2’b01, 2’b10, 2’b11
2’b00, 2’b01, 2’b10, 2’b11
2’b00, 2’b01, 2’b10, 2’b11
1’b0, 1’b1
1’b0, 1’b1
17-bit hexadecimal number
17-bit hexadecimal number
1’b0, 1’b1
1’b0, 1’b1
1’b0, 1’b1
1’b0, 1’b1