AT45DB641里的buffer是做什么用的
时间: 2023-11-12 20:56:02 浏览: 33
AT45DB641是一种数据闪存芯片,具有内置缓冲区(buffer)。该缓冲区用于存储写入或读取操作的数据。在写入操作期间,首先将数据存储在缓冲区中,然后再将其写入闪存芯片的指定位置。这样可以提高写入操作的效率和可靠性。在读取操作期间,也可以使用缓冲区来存储从闪存芯片中读取的数据,以加快读取速度。因此,缓冲区是AT45DB641中非常重要的组成部分。
相关问题
AT45DB641从flash读取数据函数,要求可自定义页和地址和数据长度
好的,以下是一个C语言的AT45DB641从flash读取数据的函数,其中页、地址和数据长度都可以自定义:
```c
#include <SPI.h>
#define AT45DB641_PAGE_SIZE 264
#define AT45DB641_PAGE_COUNT 8192
#define AT45DB641_BLOCK_SIZE 264
void readFromFlash(uint16_t page, uint16_t address, uint16_t length, uint8_t* buffer) {
uint32_t start_address = ((uint32_t)page * AT45DB641_PAGE_SIZE + address) % (AT45DB641_PAGE_SIZE * AT45DB641_PAGE_COUNT);
uint16_t remaining_length = length;
uint16_t current_address = start_address;
uint8_t* current_buffer = buffer;
while (remaining_length > 0) {
uint16_t current_length = min(remaining_length, AT45DB641_BLOCK_SIZE - (current_address % AT45DB641_BLOCK_SIZE));
uint8_t read_command[] = {0x0B, (current_address >> 16) & 0xFF, (current_address >> 8) & 0xFF, current_address & 0xFF, 0x00, 0x00, 0x00};
SPI.beginTransaction(SPISettings(10000000, MSBFIRST, SPI_MODE0));
digitalWrite(SS, LOW);
SPI.transfer(read_command, sizeof(read_command));
SPI.transfer(current_buffer, current_length);
digitalWrite(SS, HIGH);
SPI.endTransaction();
remaining_length -= current_length;
current_address += current_length;
current_buffer += current_length;
}
}
```
这个函数首先计算出从哪个地址开始读取数据,然后循环读取数据块直到读取完整个数据长度。在循环中,它会计算出当前块的长度(不超过264字节),构造读取命令,发送命令和数据,然后更新剩余的数据长度、地址和缓冲区指针。注意,这个函数需要使用SPI库进行通信,需要先调用SPI.begin()初始化SPI,并将AT45DB641的片选引脚连接到Arduino的SS引脚上。
PS E:\Project\migration\config> node testConnection.js Error: NJS-112: internal error: read integer of length 64 when expecting integer of no more than length 4 at Object.throwErr (E:\Project\migration\node_modules\oracledb\lib\errors.js:588:10) at ReadPacket._readInteger (E:\Project\migration\node_modules\oracledb\lib\thin\protocol\buffer.js:100:14) at ReadPacket.readUB4 (E:\Project\migration\node_modules\oracledb\lib\thin\protocol\buffer.js:491:17) at ReadPacket._readBytesWithLength (E:\Project\migration\node_modules\oracledb\lib\thin\protocol\packet.js:160:36) at ReadPacket.readBytesWithLength (E:\Project\migration\node_modules\oracledb\lib\thin\protocol\buffer.js:364:17) at ReadPacket.readStr (E:\Project\migration\node_modules\oracledb\lib\thin\protocol\buffer.js:463:22) at AuthMessage.processReturnParameter (E:\Project\migration\node_modules\oracledb\lib\thin\protocol\messages\auth.js:308:21) at AuthMessage.processMessage (E:\Project\migration\node_modules\oracledb\lib\thin\protocol\messages\base.js:213:12) at AuthMessage.process (E:\Project\migration\node_modules\oracledb\lib\thin\protocol\messages\base.js:196:12) at AuthMessage.decode (E:\Project\migration\node_modules\oracledb\lib\thin\protocol\messages\base.js:187:10) { code: 'NJS-112' } PS E:\Project\migration\config>
根据你提供的信息,这是一个 Node.js 应用程序中的 Oracle 数据库连接问题。错误信息显示出现了一个内部错误,该错误可能与读取长度为 64 的整数有关。建议检查数据库连接字符串和 Oracle 客户端库的版本是否匹配,还可以尝试更新或重新安装 Oracle 客户端库。此外,还可以查看 Oracle 数据库是否已正确配置并正在运行。