UART TX_CALLBALL_SIZE问题

嗨对话工程师，

我正在使用DSPS应用程序固件作为我的基准代码开始。
I have a DA communicating with an external MCU via the UART line. This UART is setup at a baudrate of 56.7kbps.

我已经实现了两个函数来向外部MCU向外部MCU发送数据。

Function 1:
- Upon DA powers up, this function reads from Flash and downloads the external MCU firmware over this UART line. This function is working consistently 100% since the external MCU can actually spin up and run with its firmware. Here is the code:

// Read QPI FWs/Tables from flash address "address" and "size" &
//将其写入QPI附加的UART频道
void user_sps_qpi_fw_upload（无符号int地址）{

BYTE buf[2];
//从主机UI闪存程序中读取存储在闪存中的字节中的固件大小。
// The firmware len is the first two bytes in each FW address section in flash
unsigned int fwlen;
if（spi_flash_read_data（buf，地址，user_flash_fwsize_hdr）== user_flash_qpi_fwsize_hdr）{
fwlen =（buf [0] << 8）|buf [1];
地址+ = user_flash_qpi_fwsize_hdr;
}
unsigned char data_ptr[USER_FLASH_QPI_CI_BLK_SIZE];
// calculate the number of flash reads. Each read is of USER_FLASH_QPI_CI_BLK_SIZE bytes
int n = fwlen / user_flash_qpi_ci_blk_size + 1;
for(int i=0; i < n; i++) {
//从闪存中读取QPI FW。这可以是fw，degamma表，lum表
unsigned int ret = spi_flash_read_data（data_ptr，地址+ i * user_flash_qpi_ci_blk_size，
user_flash_qpi_ci_blk_size）;
uart2_write(data_ptr, USER_FLASH_QPI_CI_BLK_SIZE, NULL);
UART2_FINISH_TRANSFERS（）;
}
}

- 在此函数中，我正在阅读user_flash_qpi_ci_blk_size = 256字节从闪存，写在UART2上。

Function 2:
- this function reads from the data coming in from the BLE line and send that across the UART2 bus to the external MCU. Below is the code:

void user_ble_push（uint8_t * wrdata，uint16_t write_amount）
{
assert_err（wrdata！= null）;
ASSERT_ERR(write_amount != 0);

bool send_flow_off = false;

//将BLE“数据”写入外围缓冲区“BLE_TO_PERIPH_BUFFER”
user_buffer_write_items(&ble_to_periph_buffer, wrdata, write_amount);

//检查缓冲区几乎已满，如果是，请发送Xoff
send_flow_off = user_check_buffer_almost_full(&ble_to_periph_buffer);

//如果必须发送Xoff，请尽快发送
if(send_flow_off) {
user_send_ble_flow_ctrl(FLOW_OFF);
}
//开始传输
__disable_irq();

if（！auart_qpi_tx_callbackbusy）{
uart_qpi_tx_callbackbusy = true;
uart_qpi_tx_callback(UART_STATUS_INIT);
}
__enable_irq();
}

——这个函数是需求方样本品的一部分ation firmware. I modified it to use for our own application. uart_qpi_tx_callback() is the same as what's in the DSPS sample. Below is the code for this function for your reference:

静态void UART_QPI_TX_CALLBALL（UINT8_T RES）
{
静态UINT8_T大小= 0;
uint8_t *periph_tx_ptr = NULL;

//function gets called from uart transmit isr or application when its not running
switch(res)
{
案例UART_STATUS_OK：
//get data and pointer
size = user_periph_pull(&periph_tx_ptr, size);
休息;
case UART_STATUS_INIT:
size = user_buffer_read_address(&ble_to_periph_buffer, &periph_tx_ptr, TX_CALLBACK_SIZE);
休息;
默认：
ASSERT_ERROR(0); //error: callback called from unknown source
}
//如果有数据可用，请通过Periph发送数据
if（size> 0）{
uart2_write(periph_tx_ptr, size, &uart_qpi_tx_callback);
返回;
}
//there is no data in the buffer so the callback is done
uart_qpi_tx_callbackbusy = false;
}

Now my questions/issues with the two functions above::

1. In function 1, I was actually using the UART write with size 256 bytes. I know that the TX FIFO size is only 16 bytes. Why and how did this even work in my case. I am not complaining. I just would like to understand it better.

2.在功能2中，我的问题将超过16个字节的问题发送到外部MCU。如果我发送了16个字节或更少，MCU收到了一切。如果我发送了超过16个字节的数据包，则不会收到超过16个字节的字节。但是，如果我要一次进入UART2_WRITE（）函数一行并浏览UART2_WRITE（）中的UART2_THR_EMPTY_ISR（），我可以看到所有数据，数据将最终正确接收到完全的数据。这将每次都会发生。如果我进入代码，它将起作用。如果我让代码运行，每次都会失败。

请让我知道你看到了什么并向我解释了什么？

Thank you for your attention,
- khai