Unexpected UART_EVENT_RX_CHAR and UART_EVENT_ERR_OVERFLOW

Hi all,

I'm using IAR EWSYN 7.41.1 and SSP 1.1.3 for development on S3A7.  When I use the UART driver to connect to Espressif’s ESP8266EX, I encounter some strange behaviors.  After the following two lines of code are executed, I keep receiving the event UART_EVENT_RX_CHAR in my callback.

g_uart1.p_api->open(g_uart1.p_ctrl, g_uart1.p_cfg);

g_uart1.p_api->write(g_uart1.p_ctrl, "AT\r\n", 4);

I have not used any g_uart1.p_api->read in my program. In addition, after around 20 UART_EVENT_RX_CHAR events, UART_EVENT_ERR_OVERFLOW is received.  Can anyone provide some hints?  Thanks in advance.

Cheers,

Stephen