Mapping block RAMs to specific address space

[Sajjad]

I am trying to load my program to a Block RAM using Data2mem, after the bitfile is generated. Here are the steps:

1. I have generated a BLOCK RAM as single port ROM with 32 bit-width and 16384 bit-depth.
2. Then translated the design without any BMM file and looked at the PlanAhead tool to see which BRAM are used and which ramloop is assigned. There are 15 ramloop lines. There are 14 PRIM36 primitives and 1 PRIM18 primitive as shown below:

BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[0].ram.r/v5_init.ram/SP.SINGLE_PRIM18.SP **(RAMB18)**

BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[1].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP **(RAMB36_EXP)**

BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[2].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP (RAMB36_EXP)

BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[3].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP (RAMB36_EXP)

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BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[14].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP (RAMB36_EXP)

3. I wrote the following .BMM file for address the ROM from 0x0000 to 0xFFFF. and add it to the xilinx project.

ADDRESS_SPACE pr_mem1 RAMB32 [0x00000000:0x0000ffff] BUS_BLOCK

BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[0].ram.r/v5_init.ram/SP.SINGLE_PRIM18.SP [31:0]; END_BUS_BLOCK; BUS_BLOCK

BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[1].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [31:0]; END_BUS_BLOCK; BUS_BLOCK

BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[2].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [31:0]; END_BUS_BLOCK; BUS_BLOCK

BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[3].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [31:0]; END_BUS_BLOCK; BUS_BLOCK

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BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[14].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [31:0]; END_BUS_BLOCK; END_ADDRESS_SPACE;

4. But when I tried to compile it again it gives me the error:

ERROR:Data2MEM:29 - Inconsistent address space size in ADDRESS_SPACE 'pr_mem1'.

Can you please help me out where the error is occurring? Is ramloop[xx] correctly used?

[Sajjad]

Dear, i have solved my problem, by selecting Algorithm="fixed primitives" and Primitive (Write Port A)= 8kx2 (for example) while generating the Block RAM and then writing the BMM file accordingly as:

ADDRESS_SPACE pr_mem1 RAMB32 [0x00000000:0x0000ffff]
	BUS_BLOCK
		BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[15].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [31:30];
		BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[14].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [29:28];
		BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[13].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [27:26];
		BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[12].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [25:24];
		BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[11].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [23:22];
		BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[10].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [21:20];
		BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[9].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [19:18];
		BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[8].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [17:16];
		BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[7].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [15:14];
		BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[6].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [13:12];
		BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[5].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [11:10];
		BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[4].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [9:8];
		BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[3].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [7:6];
		BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[2].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [5:4];
		BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[1].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [3:2];
		BROM_instance/U0/xst_blk_mem_generator/gnativebmg.native_blk_mem_gen/valid.cstr/ramloop[0].ram.r/v5_init.ram/SP.SINGLE_PRIM36.SP [1:0];
	END_BUS_BLOCK;
END_ADDRESS_SPACE;

and then it works fine.

[jpeyron]

Hi @Sajjad,

I have reached out to more experience engineers to see if they have any input for you.

thank you,

Jon

[jpeyron]

HI @Sajjad,

Glad to hear that you solved the issue. Thank you for posting what you did to get it working correctly.

thank you,

Jon