1、背景介绍
ZYNQ在PS部分有两路I2C，但有时候存在不够用的情况，这时就需要使用PL部分的I2C IP核（以下简称AXI I2C）。关于该IP核的信息可以参考XILINX官方的datasheet，不过在使用AXI I2C时需要进行修改才能够正确进行收发数。
2、硬件配置
如下图所示，需要在PL部分添加AXI I2C，注意这里直接把中断信号连入ZYNQ PS部分的IRQ
在ZYNQ PS中启用PL-PS中断
由于AXI I2C中断只有一种类型，所以这里启用的中断ID为61，即61号中断，后面会用到。
3、master端代码
在xilinx sdk中提供的axi i2c master示例代码使用了PL部分的INTC IP核，这与硬件设计不符，所以需要对示例代码进行改动才能正常工作。
首先是修改中断部分，修改为使用PS部分的GIC中断，如下图
IIC_INT_VEC_ID这里指定的是FPGA0_INT_ID，其实就是61，如下图，这样就把中断引脚配置了。
然后就需要对中断进行初始化，具体参考master端发送代码。这里是基于xiic_repeated_start_example这个例子改动的。
/******************************************************************************
*
* Copyright (C) 2006 - 2014 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 xiic_repeated_start_example.c
*
* This file consists of a interrupt mode design example to demonstrate the use
* of repeated start using the XIic driver.
*
* The XIic_MasterSend() API is used to transmit the data and XIic_MasterRecv()
* API is used to receive the data.
*
* The IIC devices that are present on the Xilinx boards donot support the
* repeated start option. These examples have been tested with an IIC
* device external to the boards.
*
* This code assumes that no Operating System is being used.
*
* @note
*
* None.
*
* <pre>
* MODIFICATION HISTORY:
*
* Ver Who Date Changes
* ----- ---- -------- -----------------------------------------------
* 1.00a mta 02/20/06 Created.
* 2.00a sdm 09/22/09 Updated to use the HAL APIs, replaced call to
* XIic_Initialize API with XIic_LookupConfig and
* XIic_CfgInitialize. Updated the example with a
* fix for CR539763 where XIic_Start was being called
* instead of XIic_Stop. Added code for setting up the
* StatusHandler callback.
*
* </pre>
*
******************************************************************************/
/***************************** Include Files *********************************/
#include "xparameters.h"
#include "xiic.h"
#include "xintc.h"
#include "xil_exception.h"
#include "xscugic.h"
/************************** 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.
*/
#define IIC_DEVICE_ID XPAR_IIC_0_DEVICE_ID
//#define INTC_DEVICE_ID XPAR_INTC_0_DEVICE_ID
//#define IIC_INTR_ID XPAR_INTC_0_IIC_0_VEC_ID
#define INTC_DEVICE_ID XPAR_SCUGIC_SINGLE_DEVICE_ID
#define IIC_INT_VEC_ID XPS_FPGA0_INT_ID
/*
* The following constant defines the address of the IIC
* device on the IIC bus. Note that since the address is only 7 bits, this
* constant is the address divided by 2.
*/
#define SLAVE_ADDRESS 0x50 /* 0xE0 as an 8 bit number. */
#define SEND_COUNT 25
#define RECEIVE_COUNT 25
/**************************** Type Definitions *******************************/
/***************** Macros (Inline Functions) Definitions *********************/
/************************** Function Prototypes ******************************/
int IicRepeatedStartExample();
static int WriteData(u16 ByteCount);
static int ReadData(u8 *BufferPtr, u16 ByteCount);
static int SetupInterruptSystem(XIic *IicInstPtr);
static void SendHandler(XIic *InstancePtr);
static void ReceiveHandler(XIic *InstancePtr);
static void StatusHandler(XIic *InstancePtr, int Event);
/************************** Variable Definitions *****************************/
XIic IicInstance;
XScuGic InterruptController;
u8 WriteBuffer[SEND_COUNT]; /* Write buffer for writing a page. */
u8 ReadBuffer[RECEIVE_COUNT]; /* Read buffer for reading a page. */
volatile u8 TransmitComplete;
volatile u8 ReceiveComplete;
/************************** Function Definitions *****************************/
/*****************************************************************************/
/**
* Main function to call the Repeated Start example.
*
* @param None.
*
* @return XST_SUCCESS if successful else XST_FAILURE.
*
* @note None.
*
******************************************************************************/
int main(void)
{
int Status;
/*
* Run the Repeated Start example.
*/
Status = IicRepeatedStartExample();
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
return XST_SUCCESS;
}
/*****************************************************************************/
/**
* This function writes and reads the data to the IIC Slave.
*
* @param None.
*
* @return XST_SUCCESS if successful else XST_FAILURE.
*
* @note None.
*
******************************************************************************/
int IicRepeatedStartExample(void)
{
u8 Index;
int Status;
XIic_Config *ConfigPtr; /* Pointer to configuration data */
/*
* Initialize the data to write and the read buffer.
*/
for (Index = 0; Index < SEND_COUNT; Index++) {
WriteBuffer[Index] = Index;
ReadBuffer[Index] = 0;
}
/*
* Initialize the IIC driver so that it is ready to use.
*/
ConfigPtr = XIic_LookupConfig(XPAR_IIC_0_DEVICE_ID);
if (ConfigPtr == NULL) {
return XST_FAILURE;
}
Status = XIic_CfgInitialize(&IicInstance, ConfigPtr,
ConfigPtr->BaseAddress);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Setup the Interrupt System.
*/
Status = SetupInterruptSystem(&IicInstance);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Set the Transmit, Receive and Status handlers.
*/
XIic_SetSendHandler(&IicInstance, &IicInstance,
(XIic_Handler) SendHandler);
XIic_SetRecvHandler(&IicInstance, &IicInstance,
(XIic_Handler) ReceiveHandler);
XIic_SetStatusHandler(&IicInstance, &IicInstance,
(XIic_StatusHandler) StatusHandler);
/*
* Set the Address of the Slave.
*/
Status = XIic_SetAddress(&IicInstance, XII_ADDR_TO_SEND_TYPE,
SLAVE_ADDRESS);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Write to the IIC Slave.
*/
while(1)
{
Status = WriteData(SEND_COUNT);
delay_SL(0x11111111);
}
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Read from the IIC Slave.
*/
Status = ReadData(ReadBuffer, RECEIVE_COUNT);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
return XST_SUCCESS;
}
void delay_SL(u32 delayCount) {
do {
__asm__("nop");
delayCount--;
} while (delayCount > 0);
}
/*****************************************************************************/
/**
* This function writes a buffer of data to IIC Slave.
*
* @param ByteCount contains the number of bytes in the buffer to be
* written.
*
* @return XST_SUCCESS if successful else XST_FAILURE.
*
* @note None.
*
******************************************************************************/
static int WriteData(u16 ByteCount)
{
int Status;
int BusBusy;
/*
* Set the defaults.
*/
TransmitComplete = 1;
/*
* Start the IIC device.
*/
Status = XIic_Start(&IicInstance);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Set the Repeated Start option.
*/
IicInstance.Options = XII_REPEATED_START_OPTION;
/*
* Send the data.
*/
Status = XIic_MasterSend(&IicInstance, WriteBuffer, ByteCount);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
xil_printf("i2c master send begin \r\n");
// delay_SL(0x11111111);
/*
* Wait till data is transmitted.
*/
while (TransmitComplete) {
}
xil_printf("i2c master TransmitComplete end \r\n");
/*
* This is for verification that Bus is not released and still Busy.
*/
BusBusy = XIic_IsIicBusy(&IicInstance);
TransmitComplete = 1;
IicInstance.Options = 0x0;
/*
* Send the Data.
*/
Status = XIic_MasterSend(&IicInstance, WriteBuffer, ByteCount);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
xil_printf("i2c master second send begin \r\n");
// delay_SL(0x11111111);
/*
* Wait till data is transmitted.
*/
while ((TransmitComplete) || (XIic_IsIicBusy(&IicInstance) == TRUE)) {
}
xil_printf("i2c master second TransmitComplete end \r\n");
/*
* Stop the IIC device.
*/
Status = XIic_Stop(&IicInstance);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
return XST_SUCCESS;
}
/*****************************************************************************/
/**
* This function reads a data from the IIC Slave into a specified buffer.
*
* @param BufferPtr contains the address of the data buffer to be filled.
* @param ByteCount contains the number of bytes to be read.
*
* @return XST_SUCCESS if successful else XST_FAILURE.
*
* @note None.
*
******************************************************************************/
static int ReadData(u8 *BufferPtr, u16 ByteCount)
{
int Status;
int BusBusy;
/*
* Set the defaults.
*/
ReceiveComplete = 1;
/*
* Start the IIC device.
*/
Status = XIic_Start(&IicInstance);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Set the Repeated Start option.
*/
IicInstance.Options = XII_REPEATED_START_OPTION;
/*
* Receive the data.
*/
Status = XIic_MasterRecv(&IicInstance, BufferPtr, ByteCount);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Wait till all the data is received.
*/
while (ReceiveComplete) {
}
/*
* This is for verification that Bus is not released and still Busy.
*/
BusBusy = XIic_IsIicBusy(&IicInstance);
ReceiveComplete = 1;
IicInstance.Options = 0x0;
/*
* Receive the Data.
*/
Status = XIic_MasterRecv(&IicInstance, BufferPtr, ByteCount);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Wait till all the data is received.
*/
while ((ReceiveComplete) || (XIic_IsIicBusy(&IicInstance) == TRUE)) {
}
/*
* Stop the IIC device.
*/
Status = XIic_Stop(&IicInstance);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
return XST_SUCCESS;
}
/*****************************************************************************/
/**
* This function setups the interrupt system so interrupts can occur for the
* IIC. The function is application-specific since the actual system may or
* may not have an interrupt controller. The IIC device could be directly
* connected to a processor without an interrupt controller. The user should
* modify this function to fit the application.
*
* @param IicInstPtr contains a pointer to the instance of the IIC which
* is going to be connected to the interrupt controller.
*
* @return XST_SUCCESS if successful else XST_FAILURE.
*
* @note None.
*
******************************************************************************/
static int SetupInterruptSystem(XIic *IicInstPtr)
{
#if 0
int Status;
if (InterruptController.IsStarted == XIL_COMPONENT_IS_STARTED) {
return XST_SUCCESS;
}
/*
* Initialize the interrupt controller driver so that it's ready to use.
*/
Status = XIntc_Initialize(&InterruptController, INTC_DEVICE_ID);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Connect the device driver handler that will be called when an
* interrupt for the device occurs, the handler defined above performs
* the specific interrupt processing for the device.
*/
Status = XIntc_Connect(&InterruptController, IIC_INTR_ID,
(XInterruptHandler) XIic_InterruptHandler,
IicInstPtr);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Start the interrupt controller so interrupts are enabled for all
* devices that cause interrupts.
*/
Status = XIntc_Start(&InterruptController, XIN_REAL_MODE);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Enable the interrupts for the IIC device.
*/
XIntc_Enable(&InterruptController, IIC_INTR_ID);
/*
* Initialize the exception table.
*/
Xil_ExceptionInit();
/*
* Register the interrupt controller handler with the exception table.
*/
Xil_ExceptionRegisterHandler(XIL_EXCEPTION_ID_INT,
(Xil_ExceptionHandler) XIntc_InterruptHandler,
&InterruptController);
/*
* Enable non-critical exceptions.
*/
Xil_ExceptionEnable();
return XST_SUCCESS;
#endif
int Status;
XScuGic_Config *IntcConfig; /* Instance of the interrupt controller */
Xil_ExceptionInit();
/*
* 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(&InterruptController, IntcConfig,
IntcConfig->CpuBaseAddress);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Connect the interrupt controller interrupt handler to the hardware
* interrupt handling logic in the processor.
*/
Xil_ExceptionRegisterHandler(XIL_EXCEPTION_ID_IRQ_INT,
(Xil_ExceptionHandler)XScuGic_InterruptHandler,
&InterruptController);
/*
* Connect the device driver handler that will be called when an
* interrupt for the device occurs, the handler defined above performs
* the specific interrupt processing for the device.
*/
Status = XScuGic_Connect(&InterruptController, IIC_INT_VEC_ID,
(Xil_InterruptHandler)XIic_InterruptHandler,
(void *)IicInstPtr);
if (Status != XST_SUCCESS) {
return Status;
}
/*
* Enable the interrupt for the Iic device.
*/
XScuGic_Enable(&InterruptController, IIC_INT_VEC_ID);
/*
* Enable interrupts in the Processor.
*/
Xil_ExceptionEnable();
return XST_SUCCESS;
}
/*****************************************************************************/
/**
* This Send handler is called asynchronously from an interrupt context and
* indicates that data in the specified buffer has been sent.
*
* @param InstancePtr is a pointer to the IIC driver instance for which
* the handler is being called for.
*
* @return None.
*
* @note None.
*
******************************************************************************/
static void SendHandler(XIic *InstancePtr)
{
TransmitComplete = 0;
}
/*****************************************************************************/
/**
* This Receive handler is called asynchronously from an interrupt context and
* indicates that data in the specified buffer has been Received.
*
* @param InstancePtr is a pointer to the IIC driver instance for which
* the handler is being called for.
*
* @return None.
*
* @note None.
*
******************************************************************************/
static void ReceiveHandler(XIic *InstancePtr)
{
ReceiveComplete = 0;
}
/*****************************************************************************/
/**
* This Status handler is called asynchronously from an interrupt
* context and indicates the events that have occurred.
*
* @param InstancePtr is a pointer to the IIC driver instance for which
* the handler is being called for.
* @param Event indicates the condition that has occurred.
*
* @return None.
*
* @note None.
*
******************************************************************************/
static void StatusHandler(XIic *InstancePtr, int Event)
{
TransmitComplete = 0;
}
注意master在发送时产生中断后进入的回调函数只有StatusHandler，send和receive handler其实都无法响应。
4、slave端代码
slave端和master类似，也需要修改中断处理那部分代码，其中中断处理回调函数如下：
slave端的源码如下，这里基于xiic_slave_example修改
/******************************************************************************
*
* Copyright (C) 2006 - 2014 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 xiic_slave_example.c
*
* This file consists of a Interrupt mode design example which uses the Xilinx
* IIC device and XIic driver to exercise the slave functionality of the IIC
* device.
*
* The XIic_SlaveSend() API is used to transmit the data and
* XIic_SlaveRecv() API is used to receive the data.
*
* The example is tested on ML300/ML310/ML403/ML501 Xilinx boards.
*
* The IIC devices that are present on the Xilinx boards donot support the Master
* functionality. This example has been tested with an off board external IIC
* Master device and the IIC device configured as a Slave.
*
* This code assumes that no Operating System is being used.
*
* @note
*
* None.
*
* <pre>
* MODIFICATION HISTORY:
*
* Ver Who Date Changes
* ----- ---- -------- -----------------------------------------------
* 1.00a mta 03/01/06 Created.
* 2.00a ktn 11/17/09 Updated to use the HAL APIs and replaced call to
* XIic_Initialize API with XIic_LookupConfig and
* XIic_CfgInitialize. Some of the macros have been
* renamed in the IIC driver and some renamed macros are
* used in this example.
* </pre>
*
******************************************************************************/
/***************************** Include Files *********************************/
#include "xparameters.h"
#include "xiic.h"
#include "xintc.h"
#include "xil_exception.h"
#include "xscugic.h"
/************************** 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.
*/
#define IIC_DEVICE_ID XPAR_IIC_0_DEVICE_ID
//#define INTC_DEVICE_ID XPAR_INTC_0_DEVICE_ID
//#define IIC_INTR_ID XPAR_INTC_0_IIC_0_VEC_ID
#define INTC_DEVICE_ID XPAR_SCUGIC_SINGLE_DEVICE_ID
#define IIC_INT_VEC_ID XPS_FPGA0_INT_ID
/*
* The following constant defines the address of the IIC device on the IIC bus.
* Since the address is only 7 bits, this constant is the address divided by 2.
*/
#define SLAVE_ADDRESS 0x50 /* 0xE0 as an 8 bit number. */
#define RECEIVE_COUNT 30
#define SEND_COUNT 30
/**************************** Type Definitions *******************************/
/***************** Macros (Inline Functions) Definitions *********************/
/************************** Function Prototypes ******************************/
int IicSlaveExample();
int SlaveWriteData(u16 ByteCount);
int SlaveReadData(u8 *BufferPtr, u16 ByteCount);
static int SetupInterruptSystem(XIic * IicInstPtr);
static void StatusHandler(XIic *InstancePtr, int Event);
static void SendHandler(XIic *InstancePtr);
static void ReceiveHandler(XIic *InstancePtr);
/************************** Variable Definitions *****************************/
XIic IicInstance; /* The instance of the IIC device. */
XScuGic InterruptController; /* The instance of the Interrupt Controller */
u8 WriteBuffer[SEND_COUNT]; /* Write buffer for writing a page. */
u8 ReadBuffer[RECEIVE_COUNT]; /* Read buffer for reading a page. */
volatile u8 TransmitComplete;
volatile u8 ReceiveComplete;
volatile u8 SlaveRead;
volatile u8 SlaveWrite;
/************************** Function Definitions *****************************/
/*****************************************************************************/
/**
* Main function to call the IIC Slave example.
*
* @param None.
*
* @return XST_SUCCESS if successful else XST_FAILURE.
*
* @note None.
*
******************************************************************************/
int main(void)
{
int Status;
/*
* Run the IIC Slave example.
*/
xil_printf("i2c slave example begin\n");
Status = IicSlaveExample();
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
return XST_SUCCESS;
}
void delay_SL(u32 delayCount) {
do {
__asm__("nop");
delayCount--;
} while (delayCount > 0);
}
/*****************************************************************************/
/**
* This function writes and reads the data as a slave. The IIC master on the bus
* initiates the transfers.
*
* @param None.
*
* @return XST_SUCCESS if successful else XST_FAILURE.
*
* @note None.
*
******************************************************************************/
int IicSlaveExample()
{
int Status;
u8 Index;
XIic_Config *ConfigPtr; /* Pointer to configuration data */
/*
* Initialize the IIC driver so that it is ready to use.
*/
ConfigPtr = XIic_LookupConfig(IIC_DEVICE_ID);
if (ConfigPtr == NULL) {
return XST_FAILURE;
}
Status = XIic_CfgInitialize(&IicInstance, ConfigPtr,
ConfigPtr->BaseAddress);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Setup the Interrupt System.
*/
Status = SetupInterruptSystem(&IicInstance);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
xil_printf("i2c slave example begin test1\r\n");
/*
* Include the Slave functions.
*/
XIic_SlaveInclude();
/*
* Set the Transmit, Receive and Status Handlers.
*/
XIic_SetStatusHandler(&IicInstance, &IicInstance,
(XIic_StatusHandler) StatusHandler);
XIic_SetSendHandler(&IicInstance, &IicInstance,
(XIic_Handler) SendHandler);
XIic_SetRecvHandler(&IicInstance, &IicInstance,
(XIic_Handler) ReceiveHandler);
// xil_printf("i2c slave example begin test2\r\n");
/*
* Set the Address as a RESPOND type.
*/
Status = XIic_SetAddress(&IicInstance, XII_ADDR_TO_RESPOND_TYPE,
SLAVE_ADDRESS);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
// xil_printf("i2c slave example begin test3\r\n");
/*
* The IIC Master on this bus should initiate the transfer
* and write data to the slave at this instance.
*/
while(1)
{
xil_printf("i2c slave example recv data\r\n");
SlaveReadData(ReadBuffer, RECEIVE_COUNT);
delay_SL(0x1fffff);
}
for (Index = 0; Index < SEND_COUNT; Index++) {
WriteBuffer[Index] = Index;
}
xil_printf("i2c slave example write data to master\r\n");
/*
* The IIC Master on this bus should initiate the transfer
* and read data from the slave.
*/
SlaveWriteData(SEND_COUNT);
return XST_SUCCESS;
}
/*****************************************************************************/
/**
* This function reads a buffer of bytes when the IIC Master on the bus writes
* data to the slave device.
*
* @param BufferPtr contains the address of the data buffer to be filled.
* @param ByteCount contains the number of bytes in the buffer to be read.
*
* @return XST_SUCCESS if successful else XST_FAILURE.
*
* @note None
*
******************************************************************************/
int SlaveReadData(u8 *BufferPtr, u16 ByteCount)
{
int Status;
int i=0;
/*
* Set the defaults.
*/
ReceiveComplete = 1;
/*
* Start the IIC device.
*/
//xil_printf("i2c slave example begin test4\r\n");
Status = XIic_Start(&IicInstance);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Set the Global Interrupt Enable.
*/
XIic_IntrGlobalEnable(IicInstance.BaseAddress);
//xil_printf("i2c slave example begin test5\r\n");
// while(1)
// {
// XIic_SlaveRecv(&IicInstance, ReadBuffer, RECEIVE_COUNT);
//delay_SL(0x1fffff);
// }
/*
* Wait for AAS interrupt and completion of data reception.
*/
while ((ReceiveComplete) || (XIic_IsIicBusy(&IicInstance) == TRUE)) {
if (SlaveRead) {
XIic_SlaveRecv(&IicInstance, ReadBuffer, RECEIVE_COUNT);
SlaveRead = 0;
}
}
xil_printf("\r\n slave readbuffer is \r\n");
for(i=0;i<25;i+=6)
{
xil_printf("[%d] 0x%x [%d] 0x%x [%d] 0x%x [%d] 0x%x [%d] 0x%x [%d] 0x%x\r\n",i,ReadBuffer[i],i+1,ReadBuffer[i+1],i+2,ReadBuffer[i+2],i+3,ReadBuffer[i+3],i+4,ReadBuffer[i+4],i+5,ReadBuffer[i+5]);
}
// xil_printf("i2c slave example begin test6\r\n");
/*
* Disable the Global Interrupt Enable.
*/
XIic_IntrGlobalDisable(IicInstance.BaseAddress);
// xil_printf("i2c slave example begin test7\r\n");
/*
* Stop the IIC device.
*/
Status = XIic_Stop(&IicInstance);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
return XST_SUCCESS;
}
/*****************************************************************************/
/**
* This function writes a buffer of bytes to the IIC bus when the IIC master
* initiates a read operation.
*
* @param ByteCount contains the number of bytes in the buffer to be
* written.
*
* @return XST_SUCCESS if successful else XST_FAILURE.
*
* @note None.
*
******************************************************************************/
int SlaveWriteData(u16 ByteCount)
{
int Status;
/*
* Set the defaults.
*/
TransmitComplete = 1;
/*
* Start the IIC device.
*/
Status = XIic_Start(&IicInstance);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Set the Global Interrupt Enable.
*/
XIic_IntrGlobalEnable(IicInstance.BaseAddress);
/*
* Wait for AAS interrupt and transmission to complete.
*/
while ((TransmitComplete) || (XIic_IsIicBusy(&IicInstance) == TRUE)) {
if (SlaveWrite) {
XIic_SlaveSend(&IicInstance, WriteBuffer, SEND_COUNT);
SlaveWrite = 0;
}
}
/*
* Disable the Global Interrupt Enable bit.
*/
XIic_IntrGlobalDisable(IicInstance.BaseAddress);
/*
* Stop the IIC device.
*/
Status = XIic_Stop(&IicInstance);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
return XST_SUCCESS;
}
/****************************************************************************/
/**
* This Status handler is called asynchronously from an interrupt context and
* indicates the events that have occurred.
*
* @param InstancePtr is not used, but contains a pointer to the IIC
* device driver instance which the handler is being called for.
* @param Event indicates whether it is a request for a write or read.
*
* @return None.
*
* @note None.
*
****************************************************************************/
static void StatusHandler(XIic *InstancePtr, int Event)
{
xil_printf("\r\n zz debug slave int occured\r\n");
/*
* Check whether the Event is to write or read the data from the slave.
*/
if (Event == XII_MASTER_WRITE_EVENT) {
/*
* Its a Write request from Master.
*/
SlaveRead = 1;
ReceiveComplete=0;
xil_printf("\r\n zz debug a Write request from Master\r\n");
} else {
/*
* Its a Read request from the master.
*/
SlaveWrite = 1;
TransmitComplete=0;
}
}
/****************************************************************************/
/**
* This Send handler is called asynchronously from an interrupt
* context and indicates that data in the specified buffer has been sent.
*
* @param InstancePtr is a pointer to the IIC driver instance for which
* the handler is being called for.
*
* @return None.
*
* @note None.
*
****************************************************************************/
static void SendHandler(XIic *InstancePtr)
{
TransmitComplete = 0;
}
/****************************************************************************/
/**
* This Receive handler is called asynchronously from an interrupt
* context and indicates that data in the specified buffer has been Received.
*
* @param InstancePtr is a pointer to the IIC driver instance for which
* the handler is being called for.
*
* @return None.
*
* @note None.
*
****************************************************************************/
static void ReceiveHandler(XIic *InstancePtr)
{
ReceiveComplete = 0;
}
/****************************************************************************/
/**
* This function setups the interrupt system so interrupts can occur for the
* IIC. The function is application-specific since the actual system may or
* may not have an interrupt controller. The IIC device could be directly
* connected to a processor without an interrupt controller. The user should
* modify this function to fit the application.
*
* @param IicInstPtr contains a pointer to the instance of the IIC which
* is going to be connected to the interrupt controller.
*
* @return XST_SUCCESS if successful else XST_FAILURE.
*
* @note None.
*
****************************************************************************/
static int SetupInterruptSystem(XIic * IicInstPtr)
{
#if 0
int Status;
if (InterruptController.IsStarted == XIL_COMPONENT_IS_STARTED) {
return XST_SUCCESS;
}
/*
* Initialize the interrupt controller driver so that it's ready to use.
*/
Status = XIntc_Initialize(&InterruptController, INTC_DEVICE_ID);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Connect the device driver handler that will be called when an
* interrupt for the device occurs, the handler defined above
* performs the specific interrupt processing for the device.
*/
Status = XIntc_Connect(&InterruptController, IIC_INTR_ID,
(XInterruptHandler) XIic_InterruptHandler,
IicInstPtr);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Start the interrupt controller so interrupts are enabled for all
* devices that cause interrupts.
*/
Status = XIntc_Start(&InterruptController, XIN_REAL_MODE);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Enable the interrupts for the IIC device.
*/
XIntc_Enable(&InterruptController, IIC_INTR_ID);
/*
* Initialize the exception table.
*/
Xil_ExceptionInit();
/*
* Register the interrupt controller handler with the exception table.
*/
Xil_ExceptionRegisterHandler(XIL_EXCEPTION_ID_INT,
(Xil_ExceptionHandler) XIntc_InterruptHandler,
&InterruptController);
/*
* Enable non-critical exceptions.
*/
Xil_ExceptionEnable();
return XST_SUCCESS;
#endif
int Status;
XScuGic_Config *IntcConfig; /* Instance of the interrupt controller */
Xil_ExceptionInit();
/*
* 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(&InterruptController, IntcConfig,
IntcConfig->CpuBaseAddress);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Connect the interrupt controller interrupt handler to the hardware
* interrupt handling logic in the processor.
*/
Xil_ExceptionRegisterHandler(XIL_EXCEPTION_ID_IRQ_INT,
(Xil_ExceptionHandler)XScuGic_InterruptHandler,
&InterruptController);
/*
* Connect the device driver handler that will be called when an
* interrupt for the device occurs, the handler defined above performs
* the specific interrupt processing for the device.
*/
Status = XScuGic_Connect(&InterruptController, IIC_INT_VEC_ID,
(Xil_InterruptHandler)XIic_InterruptHandler,
(void *)IicInstPtr);
if (Status != XST_SUCCESS) {
return Status;
}
/*
* Enable the interrupt for the Iic device.
*/
XScuGic_Enable(&InterruptController, IIC_INT_VEC_ID);
/*
* Enable interrupts in the Processor.
*/
Xil_ExceptionEnable();
return XST_SUCCESS;
}
5、测试
最后看一下效果，两块板子，一块做master，一块做slave，slave能够正确收到递增数了。
————————————————
版权声明：本文为CSDN博主「Felven」的原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/jj12345jj198999/java/article/details/102527417
来源：oschina
链接：https://my.oschina.net/u/2963604/blog/4284729