Achronix Speedster22i User Macro Guide - Manual (Page 112)

Memories BRAM80K
Speedster22i Macro Cell Library Achronix Semiconductor Proprietary PAGE 95
initpx_00 – initpx_31
The initpx_00 through initpx_31 parameters define the initial contents of the memory contents
associated with doutpxa[3:0] and doutpxb[3:0]. Each 256‐bit parameter associated with the
BRAM80K memory is defined in the
Memory Initialization section.
Memory Organization and Data Input / Output Pin Assignments
The BRAM80K memory block supports memory widths from one to forty bits wide. The
width
of the dina(dinb) data input is determined by the
porta_write_width(portb_write_width) parameter while the width of the douta(doutb) data
output is determined by the porta_read_width(portb_read_width) parameter. The width of
read port may be set to be different from the width of the write port on a per‐port basis.
Additionally, the width of the Port A read/write may be set to be different from the Port B
read/write widths. There are, however, some limitations of the port width assignments
between the read and write width assignments as well as the Port A and Port B width
assignments. The valid port widths defined in
Table 6‐2: BRAM80K Parameters may be
divided into three groups:
• Group1 (n x 5 widths): 40, 20, 10, 5
• Group2 (n x 9 widths): 36, 18, 9
• Group3 (n x 2 widths): 32, 16, 8, 4, 2, 1
Table 6-5: Valid Port A Width Versus Port B Width Combinations per port for n x 5 width modes
Port A
Width
Port B Width
2kx40 4kx20 8kx10 16kx5 Other
40
20
10
5
Table 6-6: Valid Port A Width Versus Port B Width Combinations per port for n x 9 width modes
Port A
Width
Port B Width
2kx36 4kx18 8kx9 Other
36
18
9
Table 6-7: Valid Port A Width Versus Write Port B Combinations per port for n x 2 width modes
Port A
Width
Port B Width
2kx32 4kx16 8kx8 16kx4 32kx2 64kx1 Other
32
16
8
4
2
1
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