Refer to the Nios® II HAL API Software provided with the 16550 UART to confirm the required register settings.
MCR must be set to 0x22 and the following registers must be enabled
MCR (5): Hardware Auto Flow Control Enable (afce)
MCR (1): Request to Send (rts)
(Reference) Software source
***_BSP > divers > src > altera_16550_uart_init.c > alt_16550_uart_config() under line 352
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Category: IP (other)
Tools: Nios® II EDS
Devices: -