目录

1、前言

2、Vivado硬件工程

3、Xilinx SDK软件工程

4、测试结果

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。