BasicRF简析.docVIP

BasicRF 简析（四：appSwitch()简析） appSwitch()在SI中的函数关系如图1所示，其中basicRfInit()和basicRfSendPacket()两个函数比较有内容的，本文主要针对这两个函数进行展开。 图1 ?????? 开始之前先介绍三个比较重要的结构体： basicRfRxInfo_t、basicRfTxState_t和 basicRfPktHdr_t //接收帧信息 typedef struct {??? uint8 seqNumber;?????//帧序号；??? uint16 srcAddr;???????? //源地址；??? uint16 srcPanId;?????? //源节点的PANID；??? int8 length;?????????????? //帧长度；??? uint8* pPayload;?????? //该指针指向帧数据即：净载荷数据；??? uint8 ackRequest;???? //帧控制域的应答位信息；??? int8 rssi;???????????????????? //接收信号强度指示；??? volatile uint8 isReady;? //通过CRC校验，数据接收完成，该标志位进行后续读取操作；??? uint8 status;????????????? //待定？？？？} basicRfRxInfo_t; //发送状态信息typedef struct {??? uint8 txSeqNumber;???? //帧序号；??? volatile uint8 ackReceived;?? //ACK是否接收完成；??? uint8 receiveOn;????????? //是否处于接收状态；??? uint32 frameCounter;?? //发送帧计数；} basicRfTxState_t; //BasicRf 帧头(IEEE 802.15.4)typedef struct {??? uint8?? packetLength;??? //帧长度；??? uint8?? fcf0;?????????? // Frame control field LSB??? uint8?? fcf1;?????????? // Frame control field MSB??? uint8?? seqNumber;????????//帧序号；??? uint16? panId;??????????????? //PANID；??? uint16? destAddr;????????? //目的地址；??? uint16? srcAddr;???????????? //源地址；??? #ifdef SECURITY_CCM? //安全选项；??? uint8?? securityControl;??? uint8? frameCounter[4];??? #endif} basicRfPktHdr_t; (一)? 关于basicRfInit() /************************************************************************************ @fn????????? basicRfInit** @brief?????? Initialise basic RF datastructures. Sets channel, short address and*????????????? PAN id in the chip and configures interrupt on packet reception*??????????????初始化BasicRF数据结构,如：通道选择、短地址、PANID及接收中断的配置；* @param?????? pRfConfig - pointer to BASIC_RF_CONFIG struct.*????????????????????????? This struct must be allocated by higher layer*????????????? txState - file scope variable that keeps tx state info???? //发送状态信息； *????????????? rxi - file scope variable info extracted from the last incoming*??????????????????? frame?????????????????????????????