高层次综合之axilite接口优化设计

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张建站

2026/4/15 7:51:10

10分钟阅读

一、axilite接口约束可以看出s_axilite可以约束除掉hls::stream以外的其他参数类型。二、关于axilite约束建议1.xilinx建议对分组到同一个axilite接口的端口不要再使用额外的IO协议当然你可以可以额外约束只要不出问题即可只是不推荐而已2.对参数array数据的优化案例一axilite RAMvoid function_top(hls::streamap_axiuPIX_W*N_PIX,1,1,1 src,hls::streamap_axiuPIX_W*N_PIX,1,1,1 dst,ap_uint32 param_arr[512]){//#pragma HLS INTERFACE ap_stable portparam_arr#pragma HLS RESOURCE variableparam_arr coreRAM_2P_BRAM//#pragma HLS ARRAY_PARTITION variableparam_arr complete dim1#pragma HLS INTERFACE axis register both portsrc#pragma HLS INTERFACE axis register both portdst#pragma HLS INTERFACE s_axilite portreturn bundleCONTROL_BUS#pragma HLS INTERFACE s_axilite portparam_arr bundleCONTROL_BUS//用户逻辑}案例二axilite ap_memoryvoid function_top(hls::streamap_axiuPIX_W*N_PIX,1,1,1 src,hls::streamap_axiuPIX_W*N_PIX,1,1,1 dst,ap_uint32 param_arr[512]){//#pragma HLS INTERFACE ap_stable portparam_arr//#pragma HLS RESOURCE variableparam_arr coreRAM_2P_BRAM//#pragma HLS ARRAY_PARTITION variableparam_arr complete dim1#pragma HLS INTERFACE axis register both portsrc#pragma HLS INTERFACE axis register both portdst#pragma HLS INTERFACE s_axilite portreturn bundleCONTROL_BUS#pragma HLS INTERFACE s_axilite portparam_arr bundleCONTROL_BUS//用户逻辑}案例三axilite ap_stable数组void function_top(hls::streamap_axiuPIX_W*N_PIX,1,1,1 src,hls::streamap_axiuPIX_W*N_PIX,1,1,1 dst,ap_uint32 param_arr[512]){#pragma HLS INTERFACE ap_stable portparam_arr//#pragma HLS RESOURCE variableparam_arr coreRAM_2P_BRAM//#pragma HLS ARRAY_PARTITION variableparam_arr complete dim1#pragma HLS INTERFACE axis register both portsrc#pragma HLS INTERFACE axis register both portdst#pragma HLS INTERFACE s_axilite portreturn bundleCONTROL_BUS#pragma HLS INTERFACE s_axilite portparam_arr bundleCONTROL_BUS//用户逻辑}上述三种案例都是将接口综合为axilite接口的bram接口也就是axilite_bram接口进行访问案例四axilite寄存器void function_top(hls::streamap_axiuPIX_W*N_PIX,1,1,1 src,hls::streamap_axiuPIX_W*N_PIX,1,1,1 dst,ap_uint32 param_arr[512]){//#pragma HLS INTERFACE ap_stable portparam_arr//#pragma HLS RESOURCE variableparam_arr coreRAM_2P_BRAM#pragma HLS ARRAY_PARTITION variableparam_arr complete dim1#pragma HLS INTERFACE axis register both portsrc#pragma HLS INTERFACE axis register both portdst#pragma HLS INTERFACE s_axilite portreturn bundleCONTROL_BUS#pragma HLS INTERFACE s_axilite portparam_arr bundleCONTROL_BUS//用户逻辑}上述四种案例中由于使用了axilite接口vivado hls保留地址0x0000到0x000c用于IO协议信号和中断信号。// // CONTROL_BUS// 0x000 : Control signals// bit 0 - ap_start (Read/Write/COH)// bit 1 - ap_done (Read/COR)// bit 2 - ap_idle (Read)// bit 3 - ap_ready (Read)// bit 7 - auto_restart (Read/Write)// others - reserved// 0x004 : Global Interrupt Enable Register// bit 0 - Global Interrupt Enable (Read/Write)// others - reserved// 0x008 : IP Interrupt Enable Register (Read/Write)// bit 0 - Channel 0 (ap_done)// bit 1 - Channel 1 (ap_ready)// others - reserved// 0x00c : IP Interrupt Status Register (Read/TOW)// bit 0 - Channel 0 (ap_done)// bit 1 - Channel 1 (ap_ready)// others - reserved// 0x800 ~// 0xfff : Memory param_mem_V (512 * 32b)// Word n : bit [31:0] - param_arr_V[n]// (SC Self Clear, COR Clear on Read, TOW Toggle on Write, COH Clear on Handshake)关于如何保证传输参数和获取参数的正确性float a3.0f,r1;u32 ua,ur1;// cast float “a” to type U32XCaculate_SetA(calculate,*((u32*)a));ur1XCaculate_GetR1(caculate);// cast return type U32 to float type for “r1”r1*((float*)ur1);四、HLS模块的函数的一次性执行流程1.使用中断函数来判定期望的中断工作方式2.为块输入端口加载寄存器值。在以上示例中此操作是使用 API 函数 XExample_Set_a、XExample_Set_b 和XExample_Set_c_i 来执行的。3.使用 XExample_Start 将 ap_start 位设置为 1以开始执行函数。此寄存器为自我清除型寄存器如以上头文件中所述。完成一次传输事务后此块将暂停操作。4.允许执行此函数。解决生成的所有中断。5.读取输出寄存器。在以上示例中这是使用 API 函数 XExample_Get_c_o_vld用于确认数据有效和XExample_Get_c_o 来执行的。需要注意的是这个流程是是完成一次函数调度如果要多次调度函数那么就重复上述步骤。五、HLS模块的函数的连续性执行流程1.使用中断函数来判定期望的中断工作方式。2.为块输入端口加载寄存器值。在以上示例中此操作是使用 API 函数 XExample_Set_a、XExample_Set_a 和XExample_Set_c_i 来执行的。3.使用 API XExample_EnableAutoRestart 设置自动启动函数4.允许执行此函数。个别端口 I/O 协议将同步通过时钟处理的数据。5.解决生成的所有中断。执行此操作期间可访问输出寄存器但数据可能多次发生变化。6.使用 API 函数 XExample_DisableAutoRestart 来停止执行。7.读取输出寄存器。在以上示例中此操作是使用 API 函数 XExample_Get_c_o 和 XExample_Set_c_o_vld 来执行的注意XExample_EnableAutoRestart表示将ap_start一直拉高也就是一轮处理完成后ap_start会自动拉高不需要设计者再次在代码中执行ap_start拉高的过程。六、MCU or ARM控制HLS IP CORE流程1.创建HLS IP硬件实例2.查找器件配置3.初始化器件4.设置HLS模块的的输入参数5.启动器件并读取结果#include xexample.h // Device driver for HLS HW block#include xparameters.h// HLS HW instance//1.创建HLS IP硬件实例XExample HlsExample;XExample_Config *ExamplePtrint main() {int res_hw;// Look Up the device configuration//2.查找器件配置ExamplePtr XExample_LookupConfig(XPAR_XEXAMPLE_0_DEVICE_ID);if (!ExamplePtr) {print(ERROR: Lookup of accelerator configuration failed.\n\r);return XST_FAILURE;}// Initialize the Device3.初始化器件status XExample_CfgInitialize(HlsExample, ExamplePtr);if (status ! XST_SUCCESS) {print(ERROR: Could not initialize accelerator.\n\r);exit(-1);}//Set the input parameters of the HLS block//4.设置HLS模块的的输入参数XExample_Set_a(HlsExample, 42);XExample_Set_b(HlsExample, 12);XExample_Set_c_i(HlsExample, 1);// Start the device and read the results//5.启动器件并读取结果XExample_Start(HlsExample);//这个start只是拉高一次ap_start如果你要多次进行处理就需要使用auto_startdo {res_hw XExample_Get_c_o(HlsExample);} while (XExample_Get_c_o(HlsExample) 0); // wait for valid data outputprint(Detected HLS peripheral complete. Result received.\n\r);}