目录
1、前言
在使用zynq芯片的时候都会遇到PS端的2个串口不够用的情况，因此本文讲述了利用IP核在zynq7020芯片的PL端扩展一个串口。
硬件：黑金7020开发板
环境：Vivado2017
2、Vivado硬件工程
1）、新建一个zynq7020的工程，并在Block Design中添加串口IP核AXI UART16550，如下图所示。
2）、设置ZYNQ里面的参数设置。
添加PS端调试串口1
开启PL端中断
设置对应的内存型号
3）、自动连线完成之后，将AXI UART16550上的中断引脚连接到ZYNQ上，并且引出AXI UART16550上的接收和发送引脚
4）、设置好引脚约束，在生成bit文件，至此PL端设置完成，打开SDK软件。
3、Xilinx SDK软件工程
1）、新建一个空白工程
2）、点击system.mss导入官方给的例程
从工程中可以看见我已经导入了两个工程，分别是发送Hello world和中断的例程。Hello world的简单一些，看一下就知道了，这里主要说明一下中断的例程。
3）、打开中断的例程，这个例程有个地方会报错，打开"xparameters.h"中找到XPAR_FABRIC_AXI_UART16550_0_IP2INTC_IRPT_INTR，替换报错的地方就行了，修改好的如下图所示。
4）、官方的代码有很多是我们不需要的，简单修改官方的代码。
/******************************************************************************
*
* Copyright (C) 2002 - 2015 Xilinx, Inc. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* Use of the Software is limited solely to applications:
* (a) running on a Xilinx device, or
* (b) that interact with a Xilinx device through a bus or interconnect.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* XILINX BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
* OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* Except as contained in this notice, the name of the Xilinx shall not be used
* in advertising or otherwise to promote the sale, use or other dealings in
* this Software without prior written authorization from Xilinx.
*
******************************************************************************/
/******************************************************************************/
/**
*
* @file xuartns550_intr_example.c
*
* This file contains a design example using the UART 16450/16550 driver
* (XUartNs550) and hardware device using interrupt mode.
*
* @note
*
* <pre>
* MODIFICATION HISTORY:
*
* Ver Who Date Changes
* ----- ---- -------- ----------------------------------------------------------
* 1.00b jhl 02/13/02 First release
* 1.00b sv 06/08/05 Minor changes to comply to Doxygen and coding guidelines
* 1.01a sv 05/08/06 Minor changes for supporting Test App Interrupt examples
* 2.00a ktn 10/20/09 Updated to use HAL processor APIs and minor modifications
* as per coding guidelines.
* 2.01a ssb 01/11/01 Updated the example to be used with the SCUGIC in
* Zynq.
* 3.2 adk 15/10/14 Clear the global counters.If multiple instance of ip is
* present in the h/w design without clearing these counters
* will result undefined behaviour for the second ip
* instance while running the peripheral tests.
* 3.4 ms 01/23/17 Added xil_printf statement in main function to
* ensure that "Successfully ran" and "Failed" strings
* are available in all examples. This is a fix for
* CR-965028.
* </pre>
******************************************************************************/
/***************************** Include Files **********************************/
#include "xparameters.h"
#include "xuartns550.h"
#include "xil_exception.h"
#ifdef XPAR_INTC_0_DEVICE_ID
#include "xintc.h"
#include <stdio.h>
#else
#include "xscugic.h"
#include "xil_printf.h"
#endif
/************************** Constant Definitions ******************************/
/*
* The following constants map to the XPAR parameters created in the
* xparameters.h file. They are defined here such that a user can easily
* change all the needed parameters in one place.
*/
#ifndef TESTAPP_GEN
#define UART_DEVICE_ID XPAR_UARTNS550_0_DEVICE_ID
#define UART_IRPT_INTR XPAR_FABRIC_AXI_UART16550_0_IP2INTC_IRPT_INTR
#ifdef XPAR_INTC_0_DEVICE_ID
#define INTC_DEVICE_ID XPAR_INTC_0_DEVICE_ID
#else
#define INTC_DEVICE_ID XPAR_SCUGIC_SINGLE_DEVICE_ID
#endif /* XPAR_INTC_0_DEVICE_ID */
#endif /* TESTAPP_GEN */
/*
* The following constant controls the length of the buffers to be sent
* and received with the UART.
*/
#define TEST_BUFFER_SIZE 10
/**************************** Type Definitions ********************************/
#ifdef XPAR_INTC_0_DEVICE_ID
#define INTC XIntc
#define INTC_HANDLER XIntc_InterruptHandler
#else
#define INTC XScuGic
#define INTC_HANDLER XScuGic_InterruptHandler
#endif /* XPAR_INTC_0_DEVICE_ID */
/************************** Function Prototypes *******************************/
int UartNs550IntrExample(INTC *IntcInstancePtr,
XUartNs550 *UartInstancePtr,
u16 UartDeviceId,
u16 UartIntrId);
void UartNs550IntrHandler(void *CallBackRef, u32 Event, unsigned int EventData);
static int UartNs550SetupIntrSystem(INTC *IntcInstancePtr,
XUartNs550 *UartInstancePtr,
u16 UartIntrId);
static void UartNs550DisableIntrSystem(INTC *IntcInstancePtr, u16 UartIntrId);
/************************** Variable Definitions ******************************/
#ifndef TESTAPP_GEN
XUartNs550 UartNs550Instance; /* Instance of the UART Device */
INTC IntcInstance; /* Instance of the Interrupt Controller */
#endif
/*
* The following buffers are used in this example to send and receive data
* with the UART.
*/
u8 SendBuffer[TEST_BUFFER_SIZE]; /* Buffer for Transmitting Data */
u8 RecvBuffer[1]; /* Buffer for Receiving Data */
/******************************************************************************/
/**
*
* Main function to call the UartNs550 interrupt example.
*
* @param None.
*
* @return XST_SUCCESS if successful, otherwise XST_FAILURE.
*
* @note None.
*
*******************************************************************************/
#ifndef TESTAPP_GEN
int main(void)
{
u16 Options;
/*
* Initialize the UART driver so that it's ready to use.
*/
XUartNs550_Initialize(&UartNs550Instance, UART_DEVICE_ID);
/*
* Perform a self-test to ensure that the hardware was built correctly.
*/
XUartNs550_SelfTest(&UartNs550Instance);
/*
* Connect the UART to the interrupt subsystem such that interrupts can
* occur. This function is application specific.
*/
UartNs550SetupIntrSystem(&IntcInstance, &UartNs550Instance, UART_IRPT_INTR);
/*
* Setup the handlers for the UART that will be called from the
* interrupt context when data has been sent and received, specify a
* pointer to the UART driver instance as the callback reference so
* the handlers are able to access the instance data.
*/
XUartNs550_SetHandler(&UartNs550Instance, UartNs550IntrHandler, &UartNs550Instance);
Options = XUN_OPTION_DATA_INTR | XUN_OPTION_FIFOS_ENABLE |XUN_OPTION_RESET_TX_FIFO;
XUartNs550_SetOptions(&UartNs550Instance, Options);
while (1) {
}
// /*
// * Disable the UartNs550 interrupt.
// */
// UartNs550DisableIntrSystem(IntcInstancePtr, UartIntrId);
}
#endif
/*****************************************************************************/
/**
*
* This function is the handler which performs processing to handle data events
* from the UartNs550. It is called from an interrupt context such that the
* amount of processing performed should be minimized.
*
* This handler provides an example of how to handle data for the UART and
* is application specific.
*
* @param CallBackRef contains a callback reference from the driver,
* in thiscase it is the instance pointer for the UART driver.
* @param Event contains the specific kind of event that has occurred.
* @param EventData contains the number of bytes sent or received for sent
* and receive events.
*
* @return None.
*
* @note None.
*
*******************************************************************************/
void UartNs550IntrHandler(void *CallBackRef, u32 Event, unsigned int EventData)
{
u8 Errors;
XUartNs550 *UartNs550Ptr = (XUartNs550 *)CallBackRef;
/*
* All of the data has been sent.
*/
if (Event == XUN_EVENT_SENT_DATA) {
xil_printf("send \r\n");
}
/*
* All of the data has been received.
*/
if (Event == XUN_EVENT_RECV_DATA) {
XUartNs550_Recv(&UartNs550Instance, RecvBuffer, 1); //重新接收一下
xil_printf("recive: %s \r\n",RecvBuffer);
}
/*
* Data was received, but not the expected number of bytes, a
* timeout just indicates the data stopped for 4 character times.
*/
if (Event == XUN_EVENT_RECV_TIMEOUT) {
xil_printf("timeout \r\n");
}
}
/******************************************************************************/
/**
*
* This function setups the interrupt system such that interrupts can occur
* for the UART. This function is application specific since the actual
* system may or may not have an interrupt controller. The UART could be
* directly connected to a processor without an interrupt controller. The
* user should modify this function to fit the application.
*
* @param IntcInstancePtr is a pointer to the instance of the Interrupt
* Controller.
* @param UartInstancePtr is a pointer to the instance of the UART.
* @param UartIntrId is the interrupt Id and is typically
* XPAR_<INTC_instance>_<UARTNS550_instance>_VEC_ID value from
* xparameters.h.
*
* @return XST_SUCCESS if successful, otherwise XST_FAILURE.
*
* @note None.
*
*******************************************************************************/
static int UartNs550SetupIntrSystem(INTC *IntcInstancePtr,
XUartNs550 *UartInstancePtr,
u16 UartIntrId)
{
int Status;
#ifdef XPAR_INTC_0_DEVICE_ID
#ifndef TESTAPP_GEN
/*
* Initialize the interrupt controller driver so that it is ready
* to use.
*/
Status = XIntc_Initialize(IntcInstancePtr, INTC_DEVICE_ID);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
#endif /* TESTAPP_GEN */
/*
* Connect a device driver handler that will be called when an interrupt
* for the device occurs, the device driver handler performs the
* specific interrupt processing for the device.
*/
Status = XIntc_Connect(IntcInstancePtr, UartIntrId,
(XInterruptHandler)XUartNs550_InterruptHandler,
(void *)UartInstancePtr);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
#ifndef TESTAPP_GEN
/*
* Start the interrupt controller such that interrupts are enabled for
* all devices that cause interrupts, specific real mode so that
* the UART can cause interrupts thru the interrupt controller.
*/
Status = XIntc_Start(IntcInstancePtr, XIN_REAL_MODE);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
#endif /* TESTAPP_GEN */
/*
* Enable the interrupt for the UartNs550.
*/
XIntc_Enable(IntcInstancePtr, UartIntrId);
#else
#ifndef TESTAPP_GEN
XScuGic_Config *IntcConfig;
/*
* Initialize the interrupt controller driver so that it is ready to
* use.
*/
IntcConfig = XScuGic_LookupConfig(INTC_DEVICE_ID);
if (NULL == IntcConfig) {
return XST_FAILURE;
}
Status = XScuGic_CfgInitialize(IntcInstancePtr, IntcConfig,
IntcConfig->CpuBaseAddress);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
#endif /* TESTAPP_GEN */
XScuGic_SetPriorityTriggerType(IntcInstancePtr, UartIntrId,
0xA0, 0x3);
/*
* Connect the interrupt handler that will be called when an
* interrupt occurs for the device.
*/
Status = XScuGic_Connect(IntcInstancePtr, UartIntrId,
(Xil_ExceptionHandler)XUartNs550_InterruptHandler,
UartInstancePtr);
if (Status != XST_SUCCESS) {
return Status;
}
/*
* Enable the interrupt for the Timer device.
*/
XScuGic_Enable(IntcInstancePtr, UartIntrId);
#endif /* XPAR_INTC_0_DEVICE_ID */
#ifndef TESTAPP_GEN
/*
* Initialize the exception table.
*/
Xil_ExceptionInit();
/*
* Register the interrupt controller handler with the exception table.
*/
Xil_ExceptionRegisterHandler(XIL_EXCEPTION_ID_INT,
(Xil_ExceptionHandler)INTC_HANDLER,
IntcInstancePtr);
/*
* Enable exceptions.
*/
Xil_ExceptionEnable();
#endif /* TESTAPP_GEN */
return XST_SUCCESS;
}
/*****************************************************************************/
/**
*
* This function disables the interrupts that occur for the UartNs550 device.
*
* @param IntcInstancePtr is the pointer to the instance of the Interrupt
* Controller.
* @param UartIntrId is the interrupt Id and is typically
* XPAR_<INTC_instance>_<UARTNS550_instance>_VEC_ID
* value from xparameters.h.
*
* @return None.
*
* @note None.
*
******************************************************************************/
static void UartNs550DisableIntrSystem(INTC *IntcInstancePtr, u16 UartIntrId)
{
/*
* Disconnect and disable the interrupt for the UartNs550 device.
*/
#ifdef XPAR_INTC_0_DEVICE_ID
XIntc_Disconnect(IntcInstancePtr, UartIntrId);
#else
XScuGic_Disable(IntcInstancePtr, UartIntrId);
XScuGic_Disconnect(IntcInstancePtr, UartIntrId);
#endif
}
4、测试结果
左边通过上位机发送”112233“到ZYNQ，ZYNQ接收到之后通过PS端的串口打印出来，如右边所示。