FPGA DNA
DNA 是 FPGA 芯片的唯一标识, FPGA 都有一个独特的 ID ,也就是 Device DNA ,这个 ID 相当于我们的身份证,在 FPGA 芯片生产的时候就已经固定在芯片的 eFuse 寄存器中,具有不可修改的属性。在 xilinx 7series 和 7series 以前,ID 都是 57bit
的,但是在 Xilinx 的 Ultraslace 架构下是 96bit 。
The 7 series FPGA contains an embedded, 64-bit device identifier which is used to provide a 57-bit Device DNA value. The identifier is nonvolatile, permanently programmed by Xilinx into the FPGA, and is unchangeable making it tamper resistant. Each device is programmed with a 57-bit DNA value that is most often unique. However, up to 32 devices within the family can contain the same DNA value. The JTAG FUSE_DNA command can be used to read the entire 64-bit value that is always unique. Device DNA is
composed of bits 0 to 56 of the 64-bit FUSE_DNA value. External applications can access the Device DNA or FUSE_DNA values through the JTAG port, and FPGA designs can access the DNA only through a Device DNA Access Port (DNA_PORT).
意思是说JTAG可以拿到57bit的DNA_PORT和64 bit的FUZE_DNA,DNA_PORT值最多会有32个器件有相同的值,FUZE_DNA就是唯一的。而如果要通过FPGA资源区读取,只能用DNA_PORT,也就是说你写逻辑的话得用57bit的DNA_PORT。
如何读取
JTAG
可以使用 JTAG 查看当前 FPGA 的 DNA 码。注意DNA_PORT更加常用,因为这个值通过逻辑也可以读出。
其中 FUSE_DNA 即为我们要获取的 DNA 编码信息,copy 即可。
代码获取
调用DNA_PORT实现。https://fpga.eetrend.com/files-eetrend-xilinx/download/201408/7594-13761-ug4707seriesconfig.pdf
DNA_PORT #(
.SIM_DNA_VALUE(57'h123456789abcdef) // Specifies a sample 57-bit DNA value for simulation
)
DNA_PORT_inst (
.DOUT(dna_dout), // 1-bit output: DNA output data.
.CLK(sys_clk), // 1-bit input: Clock input.
.DIN(1'b0), // 1-bit input: User data input pin.
.READ(dna_read), // 1-bit input: Active high load DNA, active low read input.
.SHIFT(dna_shift) // 1-bit input: Active high shift enable input.
);
使用DNA_PORT获取的DNA和JTAG读取的DNA对比
参考
AMD Customer Community JTAG 获取 DNA