如何约束非零值的字对齐地址？
[英]How to constrain a word aligned address which is non zero value?
问题描述
我想在 Packet 类中限制我的地址，以便
- 地址为非 0
- addr 是字对齐的
addr 是 32 位解压缩的 32 位向量数组，它在 Packet 类中声明为
class Packet;
rand bit [31:0] dest_addr;
rand bit [31:0] source_addr;
rand bit [7:0] data_length;
rand byte data[];
rand byte fcs;
rand bit [31:0] addr [0:3];
string name;
rand bit [28:0] n;
rand bit [3:0] test;
static int count;
rand da_kind_t da_kind;
rand fcs_kind_t fcs_kind;
rand length_kind_t length_kind;
constraint c_n {
n != 0;
}
//Word alignment constraint
constraint c_addr {
foreach(addr[i])
addr[i] == 4*n;
}
带有错误消息：
Driver_mem.sv(20): randomize() failed due to conflicts between the following constraints:
# Packet.sv(29): c_n { (n != 0); }
# Where:
# n = 29'h00000000 /* non-random */
# ** Note: (vsim-7130) Enabling enhanced debug (-solvefaildebug=2) may generate a more descriptive constraint contradiction report.
# Time: 0 ps Iteration: 2 Instance: /tb_router/test
# ** Note: (vsim-7106) Use vsim option '-solvefailtestcase[=filename]' to generate a simplified testcase that will reproduce the failure.
# Time: 0 ps Iteration: 2 Instance: /tb_router/test
但是约束解析器失败了。 我也试过这些方法，也都失败了。
constraint c_addr {
foreach(addr[i])
addr[i][31:2] != 0;
addr[i][1:0] == 0;
}
这个方法也失败
constraint c_addr {
addr[0] > 0;
addr[1] > 0;
addr[2] > 0;
addr[3] > 0;
}
constraint c_addr1 {
foreach(addr[i])
addr[i][1:0] == 0;
}
带有输出消息：
Driver_mem.sv(20): randomize() failed due to conflicts between the following constraints:
# Packet.sv(23): c_addr { (addr[0] > 0); }
# Packet.sv(24): c_addr { (addr[1] > 0); }
# Packet.sv(25): c_addr { (addr[2] > 0); }
# Packet.sv(26): c_addr { (addr[3] > 0); }
# Packet.sv(31): c_addr1 { (addr[3][1:0] == 0); }
# Packet.sv(31): c_addr1 { (addr[2][1:0] == 0); }
# Packet.sv(31): c_addr1 { (addr[1][1:0] == 0); }
# Packet.sv(31): c_addr1 { (addr[0][1:0] == 0); }
# Packet.sv(97): c_dest_addr { (dest_addr inside { addr[3], addr[2], addr[1], addr[0] }); }
# Where:
# addr[0][1:0] = 2'h0
# addr[1][1:0] = 2'h0
# addr[2][1:0] = 2'h0
# addr[3][1:0] = 2'h0
# dest_addr = 0 /* non-random */
# Given:
# bit [31:0] addr[3]
# bit [31:0] addr[2]
# bit [31:0] addr[1]
# bit [31:0] addr[0]
这 4 种方法虽然不会失败，但输出为
# addr0: 0x00000000
# addr1: 0x00000000
# addr2: 0x00000000
# addr3: 0x00000000
//Word alignment constraint
constraint c_addr {
foreach(addr[i]) {
addr[i][31:2] != 0;
addr[i][1:0] == 0;
}
}
constraint c_addr0 {
addr[0] == 4*(n+1);
addr[1] == 4*(n+2);
addr[2] == 4*(n+3);
addr[3] == 4*(n+4);
}
constraint c_addr0 {
addr[0] == 4*(n+1);
addr[1] == addr[0] + 4;
addr[2] == addr[1] + 4;
addr[3] == addr[2] + 4;
}
constraint c_addr0 {
foreach(addr[i])
addr[i] == (i+4);
}
数据包用于 1x4 路由器验证，要求目标端口的地址必须字对齐，同时非 0 值。 任何帮助表示赞赏。 另外，请注意，addr 只被随机化一次，即只有一组 4 个唯一的非 0 字对齐地址，如果我只提供字对齐约束，我总是在数组中得到一个 0x00000000 的 addr。
2 个解决方案
解决方案1
0 2020-10-12 02:50:20
我想在 Packet 类中限制我的地址，以便
- 地址为非 0
- addr 是字对齐的
addr 是 32 位解压缩的 32 位向量数组，它在 Packet 类中声明为
class Packet;
rand bit [31:0] dest_addr;
rand bit [31:0] source_addr;
rand bit [7:0] data_length;
rand byte data[];
rand byte fcs;
rand bit [31:0] addr [0:3];
string name;
rand bit [28:0] n;
rand bit [3:0] test;
static int count;
rand da_kind_t da_kind;
rand fcs_kind_t fcs_kind;
rand length_kind_t length_kind;
constraint c_n {
n != 0;
}
//Word alignment constraint
constraint c_addr {
foreach(addr[i])
addr[i] == 4*n;
}
带有错误消息：
Driver_mem.sv(20): randomize() failed due to conflicts between the following constraints:
# Packet.sv(29): c_n { (n != 0); }
# Where:
# n = 29'h00000000 /* non-random */
# ** Note: (vsim-7130) Enabling enhanced debug (-solvefaildebug=2) may generate a more descriptive constraint contradiction report.
# Time: 0 ps Iteration: 2 Instance: /tb_router/test
# ** Note: (vsim-7106) Use vsim option '-solvefailtestcase[=filename]' to generate a simplified testcase that will reproduce the failure.
# Time: 0 ps Iteration: 2 Instance: /tb_router/test
但是约束解析器失败了。 我也试过这些方法，也都失败了。
constraint c_addr {
foreach(addr[i])
addr[i][31:2] != 0;
addr[i][1:0] == 0;
}
这个方法也失败
constraint c_addr {
addr[0] > 0;
addr[1] > 0;
addr[2] > 0;
addr[3] > 0;
}
constraint c_addr1 {
foreach(addr[i])
addr[i][1:0] == 0;
}
带有输出消息：
Driver_mem.sv(20): randomize() failed due to conflicts between the following constraints:
# Packet.sv(23): c_addr { (addr[0] > 0); }
# Packet.sv(24): c_addr { (addr[1] > 0); }
# Packet.sv(25): c_addr { (addr[2] > 0); }
# Packet.sv(26): c_addr { (addr[3] > 0); }
# Packet.sv(31): c_addr1 { (addr[3][1:0] == 0); }
# Packet.sv(31): c_addr1 { (addr[2][1:0] == 0); }
# Packet.sv(31): c_addr1 { (addr[1][1:0] == 0); }
# Packet.sv(31): c_addr1 { (addr[0][1:0] == 0); }
# Packet.sv(97): c_dest_addr { (dest_addr inside { addr[3], addr[2], addr[1], addr[0] }); }
# Where:
# addr[0][1:0] = 2'h0
# addr[1][1:0] = 2'h0
# addr[2][1:0] = 2'h0
# addr[3][1:0] = 2'h0
# dest_addr = 0 /* non-random */
# Given:
# bit [31:0] addr[3]
# bit [31:0] addr[2]
# bit [31:0] addr[1]
# bit [31:0] addr[0]
这 4 种方法虽然没有失败，但输出为
# addr0: 0x00000000
# addr1: 0x00000000
# addr2: 0x00000000
# addr3: 0x00000000
//Word alignment constraint
constraint c_addr {
foreach(addr[i]) {
addr[i][31:2] != 0;
addr[i][1:0] == 0;
}
}
constraint c_addr0 {
addr[0] == 4*(n+1);
addr[1] == 4*(n+2);
addr[2] == 4*(n+3);
addr[3] == 4*(n+4);
}
constraint c_addr0 {
addr[0] == 4*(n+1);
addr[1] == addr[0] + 4;
addr[2] == addr[1] + 4;
addr[3] == addr[2] + 4;
}
constraint c_addr0 {
foreach(addr[i])
addr[i] == (i+4);
}
数据包用于 1x4 路由器验证，要求目标端口的地址必须字对齐，同时非 0 值。 任何帮助表示赞赏。 另外，请注意 addr 只随机化一次，即只有一组 4 个唯一的非 0 字对齐地址，如果我只提供字对齐约束，我总是在数组中得到一个 0x00000000 的 addr。
解决方案2
0 2021-12-17 06:07:28
字对齐意味着 2 LSB = 0 ，对。 为什么这么难？ 我是不是在这里遗漏了什么，是不是就这么简单
constraint
(addr[1:0] == 0)
(addr[31:2] !=0)
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