單片機型號：STM32L053R8T6

本系列開發(fā)日志，將詳述SX1268驅(qū)動程序的整個設(shè)計過程，本篇介紹數(shù)據(jù)緩存的相關(guān)驅(qū)動程序。

一、工作原理

二、接收模式的數(shù)據(jù)緩存

In receive mode RxBaseAddr specifies the buffer offset in memory at which the received packet payload data will be written. The buffer offset of the last byte written in receive mode is then stored in RxDataPointer which is initialized to the value of RxBaseAddr at the beginning of the reception.（接收之前，需初始化RxBaseAddr，接收到的有效數(shù)據(jù)從RxBaseAddr 寫入，最后1個字節(jié)的偏移量，存儲于RxDataPointer 中）

The pointer to the first byte of the last packet received and the packet length can be read with the command GetRxbufferStatus().（接收到的最后1包第個字節(jié)的指針和包長，可以通過GetRxbufferStatus命令讀出）

In single mode, RxDataPointer is automatically initialized to RxBaseAddr each time the transceiver enters Rx mode. In continuous mode the pointer is incremented starting from the previous position.（在單模式下，每當收發(fā)器進入Rx模式時，RxDataPointer都會自動初始化為RxBaseAddr。在連續(xù)模式下，指針從上一個位置開始遞增。）

三、發(fā)送模式數(shù)據(jù)緩存

Upon each transition to transmit mode TxDataPointer is initialized to TxBaseAddr and is incremented each time a byte is sent over the air. This operation stops once the number of bytes sent equals the payloadlength parameter as defined in the function SetPacketParams(...).（每次轉(zhuǎn)換到傳輸模式時，TxDataPointer都會初始化為TxBaseAddr，并在每次通過空中發(fā)送一個字節(jié)時遞增。一旦發(fā)送的字節(jié)數(shù)等于函數(shù)SetPacketParams中定義的payloadlength參數(shù)，此操作將停止）

四、使用數(shù)據(jù)緩存

Both, RxBaseAddr and TxBaseAddr are set using the command SetBufferBaseAddresses(...).（RxBaseAddr 和TxBaseAddr 都使用SetBufferBaseAddresses函數(shù)設(shè)置）

By default RxBaseAddr and TxBaseAddr are initialized at address 0x00.（缺省，RxBaseAddr 和TxBaseAddr 初始化為0x00）

Due to the contiguous nature of the data buffer, the base addresses for Tx and Rx are fully configurable across the 256-byte memory area. Each pointer can be set independently anywhere within the buffer. To exploit the maximum data buffer size in transmit or receive mode, the whole data buffer can be used in each mode by setting the base addresses TxBaseAddr and RxBaseAddr at the bottom of the memory (0x00).（由于數(shù)據(jù)緩沖區(qū)的連續(xù)特性，Tx和Rx的基本地址可以在256字節(jié)的內(nèi)存區(qū)域內(nèi)完全配置。每個指針都可以在緩沖區(qū)的任何地方獨立設(shè)置。要在傳輸或接收模式下利用最大數(shù)據(jù)緩沖區(qū)大小，可以在每個模式下使用整個數(shù)據(jù)緩沖區(qū)，方法是在內(nèi)存的底部設(shè)置基本地址TxBaseAddr和RxBaseAddr (0x00)）

The data buffer is cleared when the device is put into Sleep mode (implying no access). The data is retained in all other modes of operation.（數(shù)據(jù)緩存在睡眠模式將會被清除，其它模式都會保留）

The data buffer is accessed via the command WriteBuffer(...) and ReadBuffer(...). In this function the parameter offset defines the address pointer of the first data to be written or read. Offset zero defines the first position of the data buffer.（數(shù)據(jù)緩沖區(qū)是通過命令WriteBuffer(…)和ReadBuffer(…)訪問的。在這個函數(shù)中，參數(shù)偏移量定義要寫入或讀取的第一個數(shù)據(jù)的地址指針。偏移量0定義數(shù)據(jù)緩沖區(qū)的第一個位置。）

Before any read or write operation it is hence necessary to initialize this offset to the corresponding beginning of the buffer. Upon reading or writing to the data buffer the address pointer will then increment automatically.（因此，在進行任何讀或?qū)懖僮髦埃斜匾獙⑦@個偏移量初始化為緩沖區(qū)的對應(yīng)起始位置。讀取或?qū)懭霐?shù)據(jù)緩沖區(qū)后，地址指針將自動遞增。）

Two possibilities exist to obtain the offset value:（有2種可能獲得偏移量）

First is to use the RxBaseAddr value since the user defines it before receiving a payload.（首先是使用RxBaseAddr值，因為用戶在接收有效負載之前定義了它。）

Second, offset can be initialized with the value of RxStartBufferPointer returned by GetRxbufferStatus(...) command.（其次，可以使用GetRxbufferStatus(…)命令返回的RxStartBufferPointer值初始化偏移量。）

五、需注意的事情

All the received data will be written to the data buffer even if the CRC is invalid, permitting user-defined post processing of corrupted data. When receiving, if the packet size exceeds the buffer memory allocated for the Rx, it will overwrite the transmit portion of the data buffer.（所有接收到的數(shù)據(jù)都將寫入數(shù)據(jù)緩沖區(qū)，即使CRC無效，也允許用戶定義損壞數(shù)據(jù)的后處理。當接收時，如果包大小超過為Rx分配的緩沖區(qū)內(nèi)存，它將覆蓋數(shù)據(jù)緩沖區(qū)的傳輸部分。）

六、SetBufferBaseAddresses函數(shù)

七、程序?qū)崿F(xiàn)

void SX126xSetBufferBaseAddress(uint8_t txBaseAddress, uint8_t rxBaseAddress);

void CSX1268::SX126xSetBufferBaseAddress(uint8_t txBaseAddress, uint8_t rxBaseAddress)

{

uint8_t buf[2];

buf[0] = txBaseAddress;

buf[1] = rxBaseAddress;

SX126xWriteCommand(RADIO_SET_BUFFERBASEADDRESS, buf, 2);

}