一步一步学ZedBoard Zynq(四)：基于AXI Lite 总线的从设备IP设计

本小节通过使用XPS中的定制IP向导(ipwiz)，为已经存在的ARM PS 系统添加用户自定IP(Custom IP )，了解AXI Lite IP基本结构，并掌握AXI Lite IP的定制方法，为后续编写复杂AXI IP打下基础。同时本小节IP定制方法同样适用于MicroBlaze处理系统。

本小节定制的是简单LED的IP，只有一个数据寄存器，向其写值就可以控制8个LED相应亮灭。

硬件平台：Digilent ZedBoard

开发环境：Windows XP 32 bit

软件： XPS 14.2 +SDK 14.2

一、创建ARM PS系统

同前面几节一样，首先使用XPS创建ARM PS系统。需要注意的是，在选择外设时，同样不要添加任何外设

二、定制AXI IP

ARM PS系统创建结束后，就可以开始定制用户自定义IP。XPS提供了Create or Import Peripheral Wizward 向导，使得用户自定义IP的创建变得非常简单。当然在熟悉了AXI IP核结构和代码编写规则后，可以直接编写自己的IP核而不使用向导。这里采用向导方式。

1、产生AXI IP外设模版

Hardware->Create or Import Peripheral Wizward ，启动向导

欢迎界面

选择从模板创建新外设

默认是将外设直接包含到当前XPS工程中

填入外设名。注意必须都是小写。这里我们建立的是my_axi_ip。下面是版本控制，可以根据需要修改。同时面板的最下方还提示了将创建名为my_axi_ip_v1_00_a的库(其实就是一个目录)，所有实现这个IP的HDL文件都在这个库中。

接下来要选择外设总线的类型。AXI4_Lite为最基本的AXI 总线，用于简单处理，所有空间访问都是通过地址/寄存器方式访问，不支持突发；AXI4是标准AXI4总线标准，支持突然，支持高速；AXI4_Stream专门为数据流而设计。

在IPIF (IP 接口) 配置，这里配置接口的一些属性，如是否是AXI 主/从设备等。我们所定制的IP是一个从设备，因而不需要使用主设备接口。

选择需啊哟的寄存器数量。因为我们只需要一个数据寄存器，这里选1。

接下来就是IPIC(IP 互联)，也就是IP的接口信号。以BUS2开头的信号，意味对IP来说，这些信号是输入信号；同样IP2BUS意味着输出信号。

这里一些信号做一些说明。

BUS2IP_WrCE（Write Chip Enable，写使能）
Active high chip enable bus to the user logic. These chip enables are asserted only during active write transaction requests with the target address space and in conjunction with the corresponding sub-address within the space. Typically used for user logic writable registers selection.

BUS2IP_Data（Write Data，写数据）
Write data bus to the user logic. Write data is accepted by the user logic during a write operation by assertion of the write acknowledgement signal and the rising edge of the Bus2IP_Clk.

BUS2IP_BE（Byte Enable，字节使能）
Byte Enable qualifiers for the requested read or write operation to the user logic. A bit in the Bus2IP_BE set to '1' indicates that the associated byte lane contains valid data. For example, if Bus2IP_BE = 0011, this indicates that byte lanes 2 and 3 contain valid data.

IPBUS2_RdAck（Read Acknowledgement，读反馈）
Active high read data qualifier providing the read acknowledgement from the user logic. Read data on the IP2Bus_Data bus is deemed valid at the rising edge of the Bus2IP_Clk and IP2Bus_RdAck asserted high by the user logic.

接下来需要使用需要使用BFM (Bus Functional Models， 总线功能模型)对外设进行仿真。本例IP很简单，不要使用。

最后，需要选择HDL类型、ISE工程支持和软件驱动模板。因为我比较习惯使用verilog，因而使用verilog模板。需要说明的是，IP接口仍然是VHDL编写，只是用户逻辑改用verilog。如果不需要使用软件驱动模板的话，可以不选上。这里选上了，但是后续编程的时候我并没有用。

最后给出了外设的信息summary。支持，my_axi_ip"外壳"基本完成。后续我们只需要对user_logic进行编写，并修改元件引脚即可。

2、编写IP

修改.mpd文件，在目录

Lab4pcoresmy_axi_ip_v1_00_adata
###################################################################
##
## Name : my_axi_ip
## Desc : Microprocessor Peripheral Description
## : Automatically generated by PsfUtility
##
###################################################################

BEGIN my_axi_ip

## Peripheral Options
OPTION IPTYPE = PERIPHERAL
OPTION IMP_NETLIST = TRUE
OPTION HDL = MIXED
OPTION IP_GROUP = MICROBLAZE:USER
OPTION DESC = MY_AXI_IP
OPTION ARCH_SUPPORT_MAP = (others=DEVELOPMENT)

## Bus Interfaces
BUS_INTERFACE BUS = S_AXI, BUS_STD = AXI, BUS_TYPE = SLAVE

## Generics for VHDL or Parameters for Verilog
PARAMETER C_S_AXI_DATA_WIDTH = 32, DT = INTEGER, BUS = S_AXI, ASSIGNMENT = CONSTANT
PARAMETER C_S_AXI_ADDR_WIDTH = 32, DT = INTEGER, BUS = S_AXI, ASSIGNMENT = CONSTANT
PARAMETER C_S_AXI_MIN_SIZE = 0x000001ff, DT = std_logic_vector, BUS = S_AXI
PARAMETER C_USE_WSTRB = 0, DT = INTEGER
PARAMETER C_DPHASE_TIMEOUT = 8, DT = INTEGER
PARAMETER C_BASEADDR = 0xffffffff, DT = std_logic_vector, MIN_SIZE = 0x100, PAIR = C_HIGHADDR, ADDRESS = BASE, BUS = S_AXI
PARAMETER C_HIGHADDR = 0x00000000, DT = std_logic_vector, PAIR = C_BASEADDR, ADDRESS = HIGH, BUS = S_AXI
PARAMETER C_FAMILY = virtex6, DT = STRING
PARAMETER C_NUM_REG = 1, DT = INTEGER
PARAMETER C_NUM_MEM = 1, DT = INTEGER
PARAMETER C_SLV_AWIDTH = 32, DT = INTEGER
PARAMETER C_SLV_DWIDTH = 32, DT = INTEGER
PARAMETER C_S_AXI_PROTOCOL = AXI4LITE, TYPE = NON_HDL, ASSIGNMENT = CONSTANT, DT = STRING, BUS = S_AXI

## Ports
PORT LED = "", DIR = O, VEC = [7:0]
PORT S_AXI_ACLK = "", DIR = I, SIGIS = CLK, BUS = S_AXI
PORT S_AXI_ARESETN = ARESETN, DIR = I, SIGIS = RST, BUS = S_AXI
PORT S_AXI_AWADDR = AWADDR, DIR = I, VEC = [(C_S_AXI_ADDR_WIDTH-1):0], ENDIAN = LITTLE, BUS = S_AXI
PORT S_AXI_AWVALID = AWVALID, DIR = I, BUS = S_AXI
PORT S_AXI_WDATA = WDATA, DIR = I, VEC = [(C_S_AXI_DATA_WIDTH-1):0], ENDIAN = LITTLE, BUS = S_AXI
PORT S_AXI_WSTRB = WSTRB, DIR = I, VEC = [((C_S_AXI_DATA_WIDTH/8)-1):0], ENDIAN = LITTLE, BUS = S_AXI
PORT S_AXI_WVALID = WVALID, DIR = I, BUS = S_AXI
PORT S_AXI_BREADY = BREADY, DIR = I, BUS = S_AXI
PORT S_AXI_ARADDR = ARADDR, DIR = I, VEC = [(C_S_AXI_ADDR_WIDTH-1):0], ENDIAN = LITTLE, BUS = S_AXI
PORT S_AXI_ARVALID = ARVALID, DIR = I, BUS = S_AXI
PORT S_AXI_RREADY = RREADY, DIR = I, BUS = S_AXI
PORT S_AXI_ARREADY = ARREADY, DIR = O, BUS = S_AXI
PORT S_AXI_RDATA = RDATA, DIR = O, VEC = [(C_S_AXI_DATA_WIDTH-1):0], ENDIAN = LITTLE, BUS = S_AXI
PORT S_AXI_RRESP = RRESP, DIR = O, VEC = [1:0], BUS = S_AXI
PORT S_AXI_RVALID = RVALID, DIR = O, BUS = S_AXI
PORT S_AXI_WREADY = WREADY, DIR = O, BUS = S_AXI
PORT S_AXI_BRESP = BRESP, DIR = O, VEC = [1:0], BUS = S_AXI
PORT S_AXI_BVALID = BVALID, DIR = O, BUS = S_AXI
PORT S_AXI_AWREADY = AWREADY, DIR = O, BUS = S_AXI

END

其中，第39行
PORT LED = "", DIR = O, VEC = [7:0]

是我们添加上的，表明我们为其添加了一个名为LED的端口，方向是输出，长度是8位。其他行代码为默认，不需要修改。

修改用户逻辑，在

Lab4pcoresmy_axi_ip_v1_00_ahdlveriloguser_logic.v
//----------------------------------------------------------------------------
// user_logic.v - module
//----------------------------------------------------------------------------
//
// ***************************************************************************
// ** Copyright (c) 1995-2012 Xilinx, Inc. All rights reserved. **
// ** **
// ** Xilinx, Inc. **
// ** XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS" **
// ** AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND **
// ** SOLUTIONS FOR XILINX DEVICES. BY PROVIDING THIS DESIGN, CODE, **
// ** OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE, **
// ** APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION **
// ** THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT, **
// ** AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE **
// ** FOR YOUR IMPLEMENTATION. XILINX EXPRESSLY DISCLAIMS ANY **
// ** WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE **
// ** IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR **
// ** REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF **
// ** INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS **
// ** FOR A PARTICULAR PURPOSE. **
// ** **
// ***************************************************************************
//
//----------------------------------------------------------------------------
// Filename: user_logic.v
// Version: 1.00.a
// Description: User logic module.
// Date: Tue Oct 09 18:28:06 2012 (by Create and Import Peripheral Wizard)
// Verilog Standard: Verilog-2001
//----------------------------------------------------------------------------
// Naming Conventions:
// active low signals: "*_n"
// clock signals: "clk", "clk_div#", "clk_#x"
// reset signals: "rst", "rst_n"
// generics: "C_*"
// user defined types: "*_TYPE"
// state machine next state: "*_ns"
// state machine current state: "*_cs"
// combinatorial signals: "*_com"
// pipelined or register delay signals: "*_d#"
// counter signals: "*cnt*"
// clock enable signals: "*_ce"
// internal version of output port: "*_i"
// device pins: "*_pin"
// ports: "- Names begin with Uppercase"
// processes: "*_PROCESS"
// component instantiations: "I_<#|FUNC>"
//----------------------------------------------------------------------------

`uselib lib=unisims_ver
`uselib lib=proc_common_v3_00_a

module user_logic
(
// -- ADD USER PORTS BELOW THIS LINE ---------------
LED,
// -- ADD USER PORTS ABOVE THIS LINE ---------------

// -- DO NOT EDIT BELOW THIS LINE ------------------
// -- Bus protocol ports, do not add to or delete
Bus2IP_Clk, // Bus to IP clock
Bus2IP_Resetn, // Bus to IP reset
Bus2IP_Data, // Bus to IP data bus
Bus2IP_BE, // Bus to IP byte enables
Bus2IP_RdCE, // Bus to IP read chip enable
Bus2IP_WrCE, // Bus to IP write chip enable
IP2Bus_Data, // IP to Bus data bus
IP2Bus_RdAck, // IP to Bus read transfer acknowledgement
IP2Bus_WrAck, // IP to Bus write transfer acknowledgement
IP2Bus_Error // IP to Bus error response
// -- DO NOT EDIT ABOVE THIS LINE ------------------
); // user_logic

// -- ADD USER PARAMETERS BELOW THIS LINE ------------
// --USER parameters added here
// -- ADD USER PARAMETERS ABOVE THIS LINE ------------

// -- DO NOT EDIT BELOW THIS LINE --------------------
// -- Bus protocol parameters, do not add to or delete
parameter C_NUM_REG = 1;
parameter C_SLV_DWIDTH = 32;
// -- DO NOT EDIT ABOVE THIS LINE --------------------

// -- ADD USER PORTS BELOW THIS LINE -----------------
output [7:0] LED;
// -- ADD USER PORTS ABOVE THIS LINE -----------------

// -- DO NOT EDIT BELOW THIS LINE --------------------
// -- Bus protocol ports, do not add to or delete
input Bus2IP_Clk;
input Bus2IP_Resetn;
input [C_SLV_DWIDTH-1 : 0] Bus2IP_Data;
input [C_SLV_DWIDTH/8-1 : 0] Bus2IP_BE;
input [C_NUM_REG-1 : 0] Bus2IP_RdCE;
input [C_NUM_REG-1 : 0] Bus2IP_WrCE;
output [C_SLV_DWIDTH-1 : 0] IP2Bus_Data;
output IP2Bus_RdAck;
output IP2Bus_WrAck;
output IP2Bus_Error;
// -- DO NOT EDIT ABOVE THIS LINE --------------------

//----------------------------------------------------------------------------
// Implementation
//----------------------------------------------------------------------------

// --USER nets declarations added here, as needed for user logic

// Nets for user logic slave model s/w accessible register example
reg [C_SLV_DWIDTH-1 : 0] slv_reg0;
wire [0 : 0] slv_reg_write_sel;
wire [0 : 0] slv_reg_read_sel;
reg [C_SLV_DWIDTH-1 : 0] slv_ip2bus_data;
wire slv_read_ack;
wire slv_write_ack;
integer byte_index, bit_index;

// USER logic implementation added here
assign LED = slv_reg0[7:0];
// ------------------------------------------------------
// Example code to read/write user logic slave model s/w accessible registers
//
// Note:
// The example code presented here is to show you one way of reading/writing
// software accessible registers implemented in the user logic slave model.
// Each bit of the Bus2IP_WrCE/Bus2IP_RdCE signals is configured to correspond
// to one software accessible register by the top level template. For example,
// if you have four 32 bit software accessible registers in the user logic,
// you are basically operating on the following memory mapped registers:
//
// Bus2IP_WrCE/Bus2IP_RdCE Memory Mapped Register
// "1000" C_BASEADDR + 0x0
// "0100" C_BASEADDR + 0x4
// "0010" C_BASEADDR + 0x8
// "0001" C_BASEADDR + 0xC
//
// ------------------------------------------------------

assign
slv_reg_write_sel = Bus2IP_WrCE[0:0],
slv_reg_read_sel = Bus2IP_RdCE[0:0],
slv_write_ack = Bus2IP_WrCE[0],
slv_read_ack = Bus2IP_RdCE[0];

// implement slave model register(s)
always @( posedge Bus2IP_Clk )
begin

if ( Bus2IP_Resetn == 1'b0 )
begin
slv_reg0 <= 0;
end
else
case ( slv_reg_write_sel )
1'b1 :
for ( byte_index = 0; byte_index <= (C_SLV_DWIDTH/8)-1; byte_index = byte_index+1 )
if ( Bus2IP_BE[byte_index] == 1 )
slv_reg0[(byte_index*8) +: 8] <= Bus2IP_Data[(byte_index*8) +: 8];
default : begin
slv_reg0 <= slv_reg0;
end
endcase

end // SLAVE_REG_WRITE_PROC

// implement slave model register read mux
always @( slv_reg_read_sel or slv_reg0 )
begin

case ( slv_reg_read_sel )
1'b1 : slv_ip2bus_data <= slv_reg0;
default : slv_ip2bus_data <= 0;
endcase

end // SLAVE_REG_READ_PROC

// ------------------------------------------------------------
// Example code to drive IP to Bus signals
// ------------------------------------------------------------

assign IP2Bus_Data = (slv_read_ack == 1'b1) ? slv_ip2bus_data : 0 ;
assign IP2Bus_WrAck = slv_write_ack;
assign IP2Bus_RdAck = slv_read_ack;
assign IP2Bus_Error = 0;

endmodule

代码中57、86行
LED,
output [7:0] LED;

表明在用户逻辑中，定义了名为LED的端口，方向是输出，长度为8。

代码中119行
assign LED = slv_reg0[7:0];

表明将slv_reg0的低8位传递给输出端口LED。其实就是实现了数据寄存器的值作用到输出端口的功能。

需要将用户逻辑和IPIF连接上，需要完成user_logic的例化

Lab4pcoresmy_axi_ip_v1_00_ahdlvhdlmy_axi_ip.vhd
------------------------------------------------------------------------------
-- my_axi_ip.vhd - entity/architecture pair
------------------------------------------------------------------------------
-- IMPORTANT:
-- DO NOT MODIFY THIS FILE EXCEPT IN THE DESIGNATED SECTIONS.
--
-- SEARCH FOR --USER TO DETERMINE WHERE CHANGES ARE ALLOWED.
--
-- TYPICALLY, THE ONLY ACCEPTABLE CHANGES INVOLVE ADDING NEW
-- PORTS AND GENERICS THAT GET PASSED THROUGH TO THE INSTANTIATION
-- OF THE USER_LOGIC ENTITY.
------------------------------------------------------------------------------
--
-- ***************************************************************************
-- ** Copyright (c) 1995-2012 Xilinx, Inc. All rights reserved. **
-- ** **
-- ** Xilinx, Inc. **
-- ** XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS" **
-- ** AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND **
-- ** SOLUTIONS FOR XILINX DEVICES. BY PROVIDING THIS DESIGN, CODE, **
-- ** OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE, **
-- ** APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION **
-- ** THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT, **
-- ** AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE **
-- ** FOR YOUR IMPLEMENTATION. XILINX EXPRESSLY DISCLAIMS ANY **
-- ** WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE **
-- ** IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR **
-- ** REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF **
-- ** INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS **
-- ** FOR A PARTICULAR PURPOSE. **
-- ** **
-- ***************************************************************************
--
------------------------------------------------------------------------------
-- Filename: my_axi_ip.vhd
-- Version: 1.00.a
-- Description: Top level design, instantiates library components and user logic.
-- Date: Tue Oct 09 18:28:06 2012 (by Create and Import Peripheral Wizard)
-- VHDL Standard: VHDL'93
------------------------------------------------------------------------------
-- Naming Conventions:
-- active low signals: "*_n"
-- clock signals: "clk", "clk_div#", "clk_#x"
-- reset signals: "rst", "rst_n"
-- generics: "C_*"
-- user defined types: "*_TYPE"
-- state machine next state: "*_ns"
-- state machine current state: "*_cs"
-- combinatorial signals: "*_com"
-- pipelined or register delay signals: "*_d#"
-- counter signals: "*cnt*"
-- clock enable signals: "*_ce"
-- internal version of output port: "*_i"
-- device pins: "*_pin"
-- ports: "- Names begin with Uppercase"
-- processes: "*_PROCESS"
-- component instantiations: "I_<#|FUNC>"
------------------------------------------------------------------------------

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_arith.all;
use ieee.std_logic_unsigned.all;

library proc_common_v3_00_a;
use proc_common_v3_00_a.proc_common_pkg.all;
use proc_common_v3_00_a.ipif_pkg.all;

library axi_lite_ipif_v1_01_a;
use axi_lite_ipif_v1_01_a.axi_lite_ipif;

------------------------------------------------------------------------------
-- Entity section
------------------------------------------------------------------------------
-- Definition of Generics:
-- C_S_AXI_DATA_WIDTH -- AXI4LITE slave: Data width
-- C_S_AXI_ADDR_WIDTH -- AXI4LITE slave: Address Width
-- C_S_AXI_MIN_SIZE -- AXI4LITE slave: Min Size
-- C_USE_WSTRB -- AXI4LITE slave: Write Strobe
-- C_DPHASE_TIMEOUT -- AXI4LITE slave: Data Phase Timeout
-- C_BASEADDR -- AXI4LITE slave: base address
-- C_HIGHADDR -- AXI4LITE slave: high address
-- C_FAMILY -- FPGA Family
-- C_NUM_REG -- Number of software accessible registers
-- C_NUM_MEM -- Number of address-ranges
-- C_SLV_AWIDTH -- Slave interface address bus width
-- C_SLV_DWIDTH -- Slave interface data bus width
--
-- Definition of Ports:
-- S_AXI_ACLK -- AXI4LITE slave: Clock
-- S_AXI_ARESETN -- AXI4LITE slave: Reset
-- S_AXI_AWADDR -- AXI4LITE slave: Write address
-- S_AXI_AWVALID -- AXI4LITE slave: Write address valid
-- S_AXI_WDATA -- AXI4LITE slave: Write data
-- S_AXI_WSTRB -- AXI4LITE slave: Write strobe
-- S_AXI_WVALID -- AXI4LITE slave: Write data valid
-- S_AXI_BREADY -- AXI4LITE slave: Response ready
-- S_AXI_ARADDR -- AXI4LITE slave: Read address
-- S_AXI_ARVALID -- AXI4LITE slave: Read address valid
-- S_AXI_RREADY -- AXI4LITE slave: Read data ready
-- S_AXI_ARREADY -- AXI4LITE slave: read addres ready
-- S_AXI_RDATA -- AXI4LITE slave: Read data
-- S_AXI_RRESP -- AXI4LITE slave: Read data response
-- S_AXI_RVALID -- AXI4LITE slave: Read data valid
-- S_AXI_WREADY -- AXI4LITE slave: Write data ready
-- S_AXI_BRESP -- AXI4LITE slave: Response
-- S_AXI_BVALID -- AXI4LITE slave: Resonse valid
-- S_AXI_AWREADY -- AXI4LITE slave: Wrte address ready
------------------------------------------------------------------------------

entity my_axi_ip is
generic
(
-- ADD USER GENERICS BELOW THIS LINE ---------------
--USER generics added here
-- ADD USER GENERICS ABOVE THIS LINE ---------------

-- DO NOT EDIT BELOW THIS LINE ---------------------
-- Bus protocol parameters, do not add to or delete
C_S_AXI_DATA_WIDTH : integer := 32;
C_S_AXI_ADDR_WIDTH : integer := 32;
C_S_AXI_MIN_SIZE : std_logic_vector := X"000001FF";
C_USE_WSTRB : integer := 0;
C_DPHASE_TIMEOUT : integer := 8;
C_BASEADDR : std_logic_vector := X"FFFFFFFF";
C_HIGHADDR : std_logic_vector := X"00000000";
C_FAMILY : string := "virtex6";
C_NUM_REG : integer := 1;
C_NUM_MEM : integer := 1;
C_SLV_AWIDTH : integer := 32;
C_SLV_DWIDTH : integer := 32
-- DO NOT EDIT ABOVE THIS LINE ---------------------
);
port
(
-- ADD USER PORTS BELOW THIS LINE ------------------
LED : out std_logic_vector(7 downto 0);
-- ADD USER PORTS ABOVE THIS LINE ------------------

-- DO NOT EDIT BELOW THIS LINE ---------------------
-- Bus protocol ports, do not add to or delete
S_AXI_ACLK : in std_logic;
S_AXI_ARESETN : in std_logic;
S_AXI_AWADDR : in std_logic_vector(C_S_AXI_ADDR_WIDTH-1 downto 0);
S_AXI_AWVALID : in std_logic;
S_AXI_WDATA : in std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
S_AXI_WSTRB : in std_logic_vector((C_S_AXI_DATA_WIDTH/8)-1 downto 0);
S_AXI_WVALID : in std_logic;
S_AXI_BREADY : in std_logic;
S_AXI_ARADDR : in std_logic_vector(C_S_AXI_ADDR_WIDTH-1 downto 0);
S_AXI_ARVALID : in std_logic;
S_AXI_RREADY : in std_logic;
S_AXI_ARREADY : out std_logic;
S_AXI_RDATA : out std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
S_AXI_RRESP : out std_logic_vector(1 downto 0);
S_AXI_RVALID : out std_logic;
S_AXI_WREADY : out std_logic;
S_AXI_BRESP : out std_logic_vector(1 downto 0);
S_AXI_BVALID : out std_logic;
S_AXI_AWREADY : out std_logic
-- DO NOT EDIT ABOVE THIS LINE ---------------------
);

attribute MAX_FANOUT : string;
attribute SIGIS : string;
attribute MAX_FANOUT of S_AXI_ACLK : signal is "10000";
attribute MAX_FANOUT of S_AXI_ARESETN : signal is "10000";
attribute SIGIS of S_AXI_ACLK : signal is "Clk";
attribute SIGIS of S_AXI_ARESETN : signal is "Rst";
end entity my_axi_ip;

------------------------------------------------------------------------------
-- Architecture section
------------------------------------------------------------------------------

architecture IMP of my_axi_ip is

constant USER_SLV_DWIDTH : integer := C_S_AXI_DATA_WIDTH;

constant IPIF_SLV_DWIDTH : integer := C_S_AXI_DATA_WIDTH;

constant ZERO_ADDR_PAD : std_logic_vector(0 to 31) := (others => '0');
constant USER_SLV_BASEADDR : std_logic_vector := C_BASEADDR;
constant USER_SLV_HIGHADDR : std_logic_vector := C_HIGHADDR;

constant IPIF_ARD_ADDR_RANGE_ARRAY : SLV64_ARRAY_TYPE :=
(
ZERO_ADDR_PAD & USER_SLV_BASEADDR, -- user logic slave space base address
ZERO_ADDR_PAD & USER_SLV_HIGHADDR -- user logic slave space high address
);

constant USER_SLV_NUM_REG : integer := 1;
constant USER_NUM_REG : integer := USER_SLV_NUM_REG;
constant TOTAL_IPIF_CE : integer := USER_NUM_REG;

constant IPIF_ARD_NUM_CE_ARRAY : INTEGER_ARRAY_TYPE :=
(
0 => (USER_SLV_NUM_REG) -- number of ce for user logic slave space
);

------------------------------------------
-- Index for CS/CE
------------------------------------------
constant USER_SLV_CS_INDEX : integer := 0;
constant USER_SLV_CE_INDEX : integer := calc_start_ce_index(IPIF_ARD_NUM_CE_ARRAY, USER_SLV_CS_INDEX);

constant USER_CE_INDEX : integer := USER_SLV_CE_INDEX;

------------------------------------------
-- IP Interconnect (IPIC) signal declarations
------------------------------------------
signal ipif_Bus2IP_Clk : std_logic;
signal ipif_Bus2IP_Resetn : std_logic;
signal ipif_Bus2IP_Addr : std_logic_vector(C_S_AXI_ADDR_WIDTH-1 downto 0);
signal ipif_Bus2IP_RNW : std_logic;
signal ipif_Bus2IP_BE : std_logic_vector(IPIF_SLV_DWIDTH/8-1 downto 0);
signal ipif_Bus2IP_CS : std_logic_vector((IPIF_ARD_ADDR_RANGE_ARRAY'LENGTH)/2-1 downto 0);
signal ipif_Bus2IP_RdCE : std_logic_vector(calc_num_ce(IPIF_ARD_NUM_CE_ARRAY)-1 downto 0);
signal ipif_Bus2IP_WrCE : std_logic_vector(calc_num_ce(IPIF_ARD_NUM_CE_ARRAY)-1 downto 0);
signal ipif_Bus2IP_Data : std_logic_vector(IPIF_SLV_DWIDTH-1 downto 0);
signal ipif_IP2Bus_WrAck : std_logic;
signal ipif_IP2Bus_RdAck : std_logic;
signal ipif_IP2Bus_Error : std_logic;
signal ipif_IP2Bus_Data : std_logic_vector(IPIF_SLV_DWIDTH-1 downto 0);
signal user_Bus2IP_RdCE : std_logic_vector(USER_NUM_REG-1 downto 0);
signal user_Bus2IP_WrCE : std_logic_vector(USER_NUM_REG-1 downto 0);
signal user_IP2Bus_Data : std_logic_vector(USER_SLV_DWIDTH-1 downto 0);
signal user_IP2Bus_RdAck : std_logic;
signal user_IP2Bus_WrAck : std_logic;
signal user_IP2Bus_Error : std_logic;

------------------------------------------
-- Component declaration for verilog user logic
------------------------------------------
component user_logic is
generic
(
-- ADD USER GENERICS BELOW THIS LINE ---------------
--USER generics added here
-- ADD USER GENERICS ABOVE THIS LINE ---------------

-- DO NOT EDIT BELOW THIS LINE ---------------------
-- Bus protocol parameters, do not add to or delete
C_NUM_REG : integer := 1;
C_SLV_DWIDTH : integer := 32
-- DO NOT EDIT ABOVE THIS LINE ---------------------
);
port
(
-- ADD USER PORTS BELOW THIS LINE ------------------
LED : out std_logic_vector(7 downto 0);
-- ADD USER PORTS ABOVE THIS LINE ------------------

-- DO NOT EDIT BELOW THIS LINE ---------------------
-- Bus protocol ports, do not add to or delete
Bus2IP_Clk : in std_logic;
Bus2IP_Resetn : in std_logic;
Bus2IP_Data : in std_logic_vector(C_SLV_DWIDTH-1 downto 0);
Bus2IP_BE : in std_logic_vector(C_SLV_DWIDTH/8-1 downto 0);
Bus2IP_RdCE : in std_logic_vector(C_NUM_REG-1 downto 0);
Bus2IP_WrCE : in std_logic_vector(C_NUM_REG-1 downto 0);
IP2Bus_Data : out std_logic_vector(C_SLV_DWIDTH-1 downto 0);
IP2Bus_RdAck : out std_logic;
IP2Bus_WrAck : out std_logic;
IP2Bus_Error : out std_logic
-- DO NOT EDIT ABOVE THIS LINE ---------------------
);
end component user_logic;

begin

------------------------------------------
-- instantiate axi_lite_ipif
------------------------------------------
AXI_LITE_IPIF_I : entity axi_lite_ipif_v1_01_a.axi_lite_ipif
generic map
(
C_S_AXI_DATA_WIDTH => IPIF_SLV_DWIDTH,
C_S_AXI_ADDR_WIDTH => C_S_AXI_ADDR_WIDTH,
C_S_AXI_MIN_SIZE => C_S_AXI_MIN_SIZE,
C_USE_WSTRB => C_USE_WSTRB,
C_DPHASE_TIMEOUT => C_DPHASE_TIMEOUT,
C_ARD_ADDR_RANGE_ARRAY => IPIF_ARD_ADDR_RANGE_ARRAY,
C_ARD_NUM_CE_ARRAY => IPIF_ARD_NUM_CE_ARRAY,
C_FAMILY => C_FAMILY
)
port map
(
S_AXI_ACLK => S_AXI_ACLK,
S_AXI_ARESETN => S_AXI_ARESETN,
S_AXI_AWADDR => S_AXI_AWADDR,
S_AXI_AWVALID => S_AXI_AWVALID,
S_AXI_WDATA => S_AXI_WDATA,
S_AXI_WSTRB => S_AXI_WSTRB,
S_AXI_WVALID => S_AXI_WVALID,
S_AXI_BREADY => S_AXI_BREADY,
S_AXI_ARADDR => S_AXI_ARADDR,
S_AXI_ARVALID => S_AXI_ARVALID,
S_AXI_RREADY => S_AXI_RREADY,
S_AXI_ARREADY => S_AXI_ARREADY,
S_AXI_RDATA => S_AXI_RDATA,
S_AXI_RRESP => S_AXI_RRESP,
S_AXI_RVALID => S_AXI_RVALID,
S_AXI_WREADY => S_AXI_WREADY,
S_AXI_BRESP => S_AXI_BRESP,
S_AXI_BVALID => S_AXI_BVALID,
S_AXI_AWREADY => S_AXI_AWREADY,
Bus2IP_Clk => ipif_Bus2IP_Clk,
Bus2IP_Resetn => ipif_Bus2IP_Resetn,
Bus2IP_Addr => ipif_Bus2IP_Addr,
Bus2IP_RNW => ipif_Bus2IP_RNW,
Bus2IP_BE => ipif_Bus2IP_BE,
Bus2IP_CS => ipif_Bus2IP_CS,
Bus2IP_RdCE => ipif_Bus2IP_RdCE,
Bus2IP_WrCE => ipif_Bus2IP_WrCE,
Bus2IP_Data => ipif_Bus2IP_Data,
IP2Bus_WrAck => ipif_IP2Bus_WrAck,
IP2Bus_RdAck => ipif_IP2Bus_RdAck,
IP2Bus_Error => ipif_IP2Bus_Error,
IP2Bus_Data => ipif_IP2Bus_Data
);

------------------------------------------
-- instantiate User Logic
------------------------------------------
USER_LOGIC_I : component user_logic
generic map
(
-- MAP USER GENERICS BELOW THIS LINE ---------------
--USER generics mapped here
-- MAP USER GENERICS ABOVE THIS LINE ---------------

C_NUM_REG => USER_NUM_REG,
C_SLV_DWIDTH => USER_SLV_DWIDTH
)
port map
(
-- MAP USER PORTS BELOW THIS LINE ------------------
LED => LED,
-- MAP USER PORTS ABOVE THIS LINE ------------------

Bus2IP_Clk => ipif_Bus2IP_Clk,
Bus2IP_Resetn => ipif_Bus2IP_Resetn,
Bus2IP_Data => ipif_Bus2IP_Data,
Bus2IP_BE => ipif_Bus2IP_BE,
Bus2IP_RdCE => user_Bus2IP_RdCE,
Bus2IP_WrCE => user_Bus2IP_WrCE,
IP2Bus_Data => user_IP2Bus_Data,
IP2Bus_RdAck => user_IP2Bus_RdAck,
IP2Bus_WrAck => user_IP2Bus_WrAck,
IP2Bus_Error => user_IP2Bus_Error
);

------------------------------------------
-- connect internal signals
------------------------------------------
ipif_IP2Bus_Data <= user_IP2Bus_Data;
ipif_IP2Bus_WrAck <= user_IP2Bus_WrAck;
ipif_IP2Bus_RdAck <= user_IP2Bus_RdAck;
ipif_IP2Bus_Error <= user_IP2Bus_Error;

user_Bus2IP_RdCE <= ipif_Bus2IP_RdCE(USER_NUM_REG-1 downto 0);
user_Bus2IP_WrCE <= ipif_Bus2IP_WrCE(USER_NUM_REG-1 downto 0);

end IMP;

137行
LED : out std_logic_vector(7 downto 0);

定义IP的端口为LED，这里需要和之前修改MPD文件一致。

232-268行为元件声明
------------------------------------------
-- Component declaration for verilog user logic
------------------------------------------
component user_logic is
generic
(
-- ADD USER GENERICS BELOW THIS LINE ---------------
--USER generics added here
-- ADD USER GENERICS ABOVE THIS LINE ---------------

-- DO NOT EDIT BELOW THIS LINE ---------------------
-- Bus protocol parameters, do not add to or delete
C_NUM_REG : integer := 1;
C_SLV_DWIDTH : integer := 32
-- DO NOT EDIT ABOVE THIS LINE ---------------------
);
port
(
-- ADD USER PORTS BELOW THIS LINE ------------------
LED : out std_logic_vector(7 downto 0);
-- ADD USER PORTS ABOVE THIS LINE ------------------

-- DO NOT EDIT BELOW THIS LINE ---------------------
-- Bus protocol ports, do not add to or delete
Bus2IP_Clk : in std_logic;
Bus2IP_Resetn : in std_logic;
Bus2IP_Data : in std_logic_vector(C_SLV_DWIDTH-1 downto 0);
Bus2IP_BE : in std_logic_vector(C_SLV_DWIDTH/8-1 downto 0);
Bus2IP_RdCE : in std_logic_vector(C_NUM_REG-1 downto 0);
Bus2IP_WrCE : in std_logic_vector(C_NUM_REG-1 downto 0);
IP2Bus_Data : out std_logic_vector(C_SLV_DWIDTH-1 downto 0);
IP2Bus_RdAck : out std_logic;
IP2Bus_WrAck : out std_logic;
IP2Bus_Error : out std_logic
-- DO NOT EDIT ABOVE THIS LINE ---------------------
);
end component user_logic;

323-352行为user_logic元件例化。VHDL是不区分大小写的。
------------------------------------------
-- instantiate User Logic
------------------------------------------
USER_LOGIC_I : component user_logic
generic map
(
-- MAP USER GENERICS BELOW THIS LINE ---------------
--USER generics mapped here
-- MAP USER GENERICS ABOVE THIS LINE ---------------

C_NUM_REG => USER_NUM_REG,
C_SLV_DWIDTH => USER_SLV_DWIDTH
)
port map
(
-- MAP USER PORTS BELOW THIS LINE ------------------
LED => LED,
-- MAP USER PORTS ABOVE THIS LINE ------------------

Bus2IP_Clk => ipif_Bus2IP_Clk,
Bus2IP_Resetn => ipif_Bus2IP_Resetn,
Bus2IP_Data => ipif_Bus2IP_Data,
Bus2IP_BE => ipif_Bus2IP_BE,
Bus2IP_RdCE => user_Bus2IP_RdCE,
Bus2IP_WrCE => user_Bus2IP_WrCE,
IP2Bus_Data => user_IP2Bus_Data,
IP2Bus_RdAck => user_IP2Bus_RdAck,
IP2Bus_WrAck => user_IP2Bus_WrAck,
IP2Bus_Error => user_IP2Bus_Error
);

这几个文件修改后保存。

Project->Rescan User Repositories（更新用户仓库？），让XPS识别到对IP所做的修改

三、将自定义IP核添加到PS系统

同第三篇一样，需要将IP添加到PS系统中。

在Ports标签中，需要将我们定义的LED端口设置为外部端口，外部引脚名按照Zedboard的习惯，定义为LD

在Address标签中，设定IP的地址。XPS支持自定义定制范围、空间大小等。可以使用默认设置，也可以手动设置。这里我设置基地址为0x40000000，其实也就是我们设定的数据寄存器的地址为0x40000000。如果有更多的寄存器，会以4字节offset 地址的方式访问即可。

最后一样修改ucf文件，完成约束。
NET LD[0] LOC = T22 | IOSTANDARD=LVCMOS33; # "LD0"
NET LD[1] LOC = T21 | IOSTANDARD=LVCMOS33; # "LD1"
NET LD[2] LOC = U22 | IOSTANDARD=LVCMOS33; # "LD2"
NET LD[3] LOC = U21 | IOSTANDARD=LVCMOS33; # "LD3"
NET LD[4] LOC = V22 | IOSTANDARD=LVCMOS33; # "LD4"
NET LD[5] LOC = W22 | IOSTANDARD=LVCMOS33; # "LD5"
NET LD[6] LOC = U19 | IOSTANDARD=LVCMOS33; # "LD6"
NET LD[7] LOC = U14 | IOSTANDARD=LVCMOS33; # "LD7"

最后对这个系统编译，生成bitstream文件，并将硬件配置导入到SDK，并启动SDK。

四、使用SDK编写IP核驱动程序和应用程序

打开SDK，可以从系统信息system.xml中看到我们的系统信息。可以看到我们实例化连接到系统的ip是my_axi_ip_0，基地址是0x4000000。

建立软件工程后，修改main代码，如下
//@超群天晴
#include
#include "xparameters.h"
#include "xil_types.h"
#include "xstatus.h"
#include "xil_io.h"//包含xil_io头文件，完成对绝对地址的访问
#include "platform.h"

#define LED_DATA_REG 0x40000000

void print(char *ptr);
void delay(unsigned int delaytime);
void LED_Play(unsigned char led);

int main(void)
{

init_platform();

print("ZedBoard LAB4: MY_AXI_LEDs ");
print("超群天晴 2012年10月8日22:12:31 ");

LED_Play(0x03);
while(1);

cleanup_platform();

return 0;
}

void delay(unsigned int delaytime)
{
int i;
for(i=0;i7);
Xil_Out32(LED_DATA_REG,led);
delay(50000000);
}
}

定义了两个函数
void delay(unsigned int delaytime);
void LED_Play(unsigned char led);

其中delay()为延时函数，参数为延时时间，100000000大约延时1s；

LED_Play()为LED流水灯函数，参数是流水初始值。在程序里面设定的是0x2，也就LD0、LD1最开始亮，然后流水。

其中第8行
#define LED_DATA_REG 0x40000000

使用宏定义，定义LED_DATA_REG，实际上就是自定义IP的基地址。

第44行
Xil_Out32(LED_DATA_REG,led);

使用了xil_io.h提供的绝对地址访问函数Xil_Out32(u32 OutAddress, u32 Value)，定义如下
/*****************************************************************************/
/**
*
* Performs an output operation for a 32-bit memory location by writing the
* specified Value to the the specified address.
*
* @param OutAddress contains the address to perform the output operation
* at.
* @param Value contains the Value to be output at the specified address.
*
* @return None.
*
* @note None.
*
******************************************************************************/
void Xil_Out32(u32 OutAddress, u32 Value)
{
/* write the contents of the I/O location and then synchronize the I/O
* such that the I/O operation completes before proceeding on
*/
*(volatile u32 *) OutAddress = Value;
SYNCHRONIZE_IO;
}

可以看出，其实现的功能就是向32位绝对地址OutAddress中写入32位无符号值Value。参考这样的写法，可以将地址访问修改
1 #define LED_DATA_ADDR 0x40000000
2 #define LED_DATA_REG(x) *(volatile unsigned int *) LED_DATA_ADDR = x

然后修改寄存器的值，只需要修改LED_DATA_REG(x)参数x的值即可。

四、运行结果

编译下载之后，可以从超级终端看到调试信息

同时Zedboard上的 LD 流水