从双向半双工模式下的字节传输结束

嗨，


我有一个STM8S003F3，在双向半双工模式下配置为从机。

在它接收字节的时间内，我可以等待RXNE标志知道字节已被完全接收。但是，我想知道发送时的同一时间。 TXE没有帮助。

让我来证明一下。当有转移时，想象这是时钟。

（TXE）-_-_-_-_-_-_-_-_（RXNE）

由于TX缓冲区被复制到移位寄存器，因此字节时钟开始时的TXE变为真。这当然仅在发送模式下发生。但这显示了传输的_beginning_。

字节时钟结束时的RXNE变为真，因为RX缓冲区被从移位寄存器复制到。这仅在接收模式下发生。

我希望能够轮询同一时刻轮询RXNE，但是在传输模式下。

我试过（似乎没问题）使用BSY标志。但是，数据表本身说：

注意：请勿使用BSY标志来处理每次数据传输或接收。最好使用TXE和RXNE标志。

如果我不能使用BSY标志，那么我可以使用什么（因为RXNE没有设置为发送模式）？
#slave #bidirectional #spi



以下为原文




Hi,


I have an STM8S003F3 that is configured as a slave in a bidirectional half-duplex mode.

During the time it receives bytes, I can wait on the RXNE flag to know the byte has been completely received. However, I want to know the same time for when it is transmitting. TXE doesn't help.

Let me demonstrate. When there is a transfer, imagine this is the clock.

(TXE)-_-_-_-_-_-_-_-_(RXNE)

TXE at the beginning of the clocking of the byte becomes true because the TX buffer gets copied to the shift register. This happens of course only in transmit mode. But this shows the _beginning_ of the transmission.

RXNE at the end of the clocking of the byte becomes true because the RX buffer gets copied to from the shift register. This happens only in receive mode.

I want to be able to poll the same moment polling RXNE would, but in transmit mode.

I have tried (and it seems to be ok) to use the BSY flag. However, the datasheet itself says:

Note: Do not use the BSY flag to handle each data transmission or reception. It is better to use TXE and RXNE flags instead.

If I can't use the BSY flag, what can I use then (Since RXNE doesn't get set in transmit mode)?  
#slave #bidirectional #spi