UART LSR[5] is not HIGH, INFINITE LOOP

[ghost]

I have written a testbench c code for simulating UART. The two functions that is used in my testbench are:

void uart_init(int parity,unsigned short clk_counter) {

    CGREG |= (1 << CGUART); // don't clock gate UART
    UART->LCR = 0x83; //sets 8N1 and set DLAB to 1
    UART->DLM = (clk_counter >> 8) & 0xFF;
    UART->DLL = clk_counter & 0xFF;
    UART->FCR = 0xA7; //enables 16byte FIFO and clear FIFOs
    UART->LCR = 0x03; //sets 8N1 and set DLAB to 0

}

and

void uart_putchar(unsigned char a) {
    while ((UART->LSR & 0x20) == 0);
    UART->THR = a;
}

But there is a infinite loop when I started to simulations because of LSR&0x20 condition is not evaluated. How can I fix this issue?