uvm_mem_mam的用法：

1. 几个相关的class:

uvm_mem_mam

uvm_mem_mam_cfg : 用来配置uvm_mem_mam，在uvm_mem_man.new()的时候引入；

uvm_mem_mam_policy: 在分配memory空间的时候用;

一般情况下需要重新定义一下；

class pcie_mem_man_policy extends uvm_mem_mam_policy;

    bit [63:0] addr_align_mask;     // 0 means no align requirement

                                    // 'b0011 means DW align

    bit [63:0] low_base = 64'h00000000_00000000;    // region cannnot exeed this limit

    bit [63:0] high_limit = 64'hFFFFFFFF_FFFFFFFF;    // region cannnot exeed this limit

    constraint addr_align_cst {

        (start_offset & addr_align_mask) == 0;

    }

 

    constraint region_limit_cst {

        start_offset >= low_base;

        {1'b0, start_offset} + len - 1 <= high_limit;

    }

endclass : pcie_mem_man_policy

2. 用法：

uvm_mem_mam mem_mam_h;

uvm_mem_mam_cfg mem_cfg_h;

pcie_mem_mam_policy mem_policy_h;

...

mem_cfg_h = new();

mem_cfg_h.start_offset = 64'h0;

mem_cfg_h.end_offset = 64'hffff_ffff_ffff_ffff;

mem_cfg_h.n_bytes = 1;

mem_mam_h = new("mem_mam_h",mem_cfg_h);

mem_policy_h = new();

mem_policy_h.low_base = 64'h0;

mem_policy_h.high_limit = 64'hffff_ffff_ffff_ffff;

2.1 随机设置地址空间

uvm_mem_region cur_region; //存储所分配的空间

int region_size=32'h1000_0000;

mem_mam_h.release_all_regions(); //释放所有分配的地址

mem_policy_h.addr_align_mask = {28{1'b1}}; //设置分配的地址低28位对齐

cur_region = mem_mam_h.request_region(region_size, mem_policy_h); //分配的地址空间大小为32'h1000_0000;

if(cur_region == null) `uvm_fatal("",""); //检查是否分配成功;

// 利用cur_region.get_start_offset()/cur_region.get_end_offset()可以获取cur_region的起始地址和结束地址；

2.2 手动分配地址

bit[63:0] cur_mem_base = 64'h8000_0000;

bit[63:0] cur_mem_limit = 64'h8fff_ffff;

mem_mam_h.reserve_region(.start_offset(cur_mem_base), .n_bytes(cur_mem_limit - cur_mem_base + 1)); //在mem_mam_h锁定这个地址，不会被随机分配给别的空间；