UART TX_CALLBACK_SIZE question

Hi Dialog Engineer,

I am using the DSPS application firmware as my baseline code to start with.
我通过UART行与外部MCU进行了通信。这款UART是在56.7kbps的波特拉特的建立。

I have implemented two functions to send data across from the DA to the external MCU.

功能1：
- 在da powers上升，此功能从Flash读取并在此UART行下载外部MCU固件。此功能始终如一地工作100％，因为外部MCU实际上可以旋转并使用固件运行。这是代码：

//从闪存地址“地址”和“尺寸”读取QPI FWS /表格和
// write it out the UART channel(s) where the QPI(s) attached to
void user_sps_qpi_fw_upload(unsigned int address) {

byte buf [2];
// read the firmware size in bytes stored in flash from the Host UI flash program.
//固件Len是Flash中每个FW地址部分中的前两个字节
unsigned int fwLen;
if(spi_flash_read_data(buf, address, USER_FLASH_QPI_FWSIZE_HDR) == USER_FLASH_QPI_FWSIZE_HDR) {
fwLen = (buf[0] << 8) | buf[1];
address += USER_FLASH_QPI_FWSIZE_HDR;
}
无符号char data_ptr [user_flash_qpi_ci_blk_size];
//计算闪存读数的数量。每个读取的是user_flash_qpi_ci_blk_size字节
int n = fwLen/USER_FLASH_QPI_CI_BLK_SIZE + 1;
for（int i = 0; i // read the QPI FW from Flash. This can be FW, Degamma Table, LUM Tables
unsigned int ret = spi_flash_read_data(data_ptr, address + 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();
}
}

- In this function, I am reading USER_FLASH_QPI_CI_BLK_SIZE = 256 bytes at a time from Flash and write over the UART2.

功能2：
- 此功能从来自BLE线的数据读取，并在UART2总线上发送到外部MCU。以下是代码：

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;

// write the BLE "data" to the peripheral buffer "ble_to_periph_buffer"
user_buffer_write_items（＆ble_to_periph_buffer，wrdata，write_amount）;

//check if buffer is almost full and issue to send a XOFF if so
send_flow_off = user_check_buffer_almost_full（＆ble_to_periph_buffer）;

//if XOFF must be send, send asap
if（send_flow_off）{
user_send_ble_flow_ctrl（flow_off）;
}
//start transmitting
__disable_irq（）;

if(!uart_qpi_tx_callbackbusy) {
UART_QPI_TX_CALLBACKBUSY = TRUE;
UART_QPI_TX_CALLBACK（UART_STATUS_INIT）;
}
__enable_irq（）;
}

- 此功能是DSPS示例应用程序固件的一部分。我修改了它用于我们自己的应用程序。UART_QPI_TX_CALLBACK（）与DSPS样本中的内容相同。下面是您参考此功能的代码：

static void uart_qpi_tx_callback(uint8_t res)
{
static uint8_t size=0;
uint8_t * periph_tx_ptr = null;

//在未运行时从UART传输ISR或应用程序调用函数
开关（RES）
{
case UART_STATUS_OK:
//获取数据和指针
size = user_periph_pull（＆periph_tx_ptr，size）;
break;
案例UART_STATUS_INIT：
size = user_buffer_read_address（＆ble_to_periph_buffer，＆periph_tx_ptr，tx_callback_size）;
break;
default:
assert_error（0）;//错误：从未知来源调用回调
}
//if there is data available, send data over periph
if(size > 0) {
UART2_WRITE（Periph_tx_ptr，size，＆uart_qpi_tx_callback）;
return;
}
//缓冲区中没有数据，因此回调已完成
uart_qpi_tx_callbackbusy = false;
}

现在我的问题/问题上面的两个功能::

1.在函数1中，我实际上使用了UART写入大小256字节。我知道TX FIFO大小只有16个字节。为什么和如何在我的情况下工作。我不抱怨。我只是想更好地了解它。

2.在函数二,我有问题发送任何东西more than 16 bytes to the external MCU. If I sent 16 bytes or less, the MCU received everything. If I sent a packet that is more than 16 bytes, the bytes beyond the 16th byte will not be received. However, if I were to step into the uart2_write() function one line at a time and walk through the uart2_thr_empty_isr() inside uart2_write(), I can see all the data and the data will end up be received by the external MCU correctly. This will happen every time. If I step into the code, it will work. If I let the code run, It will fail every time.

Please let me know what you see and explain to me what's going on?

感谢您的关注，
--Khai