Xilinx virtex-5 fpga

142 www.xilinx.com Virtex-5 FPGA User Guide
UG190 (v5.0) June 19, 2009
Chapter 4: Block RAM
FIFO Architecture: a Top-Level View
Figure 4-17 shows a top-level view of the Virtex-5 FIFO architecture. The read pointer,
write pointer, and status flag logic are dedicated for FIFO use only.
FIFO Primitives
Figure 4-18 shows the FIFO36 primitive.
X-Ref Target - Figure 4-17
Figure 4-17: Top-Level View of FIFO in Block RAM
Block
RAM
WRCOUNT RDCOUNT
WRCLK
WREN
RDCLK
DO/DOPDIN/DINP
RDEN
RST
Status Flag
Logic
FULL EMPTY ALMOSTFULL ALMOSTEMPTY RDERR WRERR
waddr raddr
oe
mem_ren
mem_wen
Write
Pointer
Read
Pointer
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X-Ref Target - Figure 4-18
Figure 4-18: FIFO36 Primitive
DOP[3:0]
DI[31:0]
DIP[3:0]
RDEN
RST
RDCLK
WREN
WRCLK
DO[31:0]
RDCOUNT[12:0]
WRCOUNT[12:0]
EMPTY
FULL
ALMOSTEMPTY
ALMOSTFULL
WRERR
RDERR
FIFO36
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