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UART1 (/dev/ttyS1) on DE0-nano-SoC does not work

Honored Contributor II

Hi! This is another question from a newbie. 


HPS in DE0-nano-SoC has 2 UARTs. First of them (UART0) is used for console (ttyS0) via USB. 

I want to use second UART (UART1) for data transfer from Linux (Debian wheezy armhf). 

I used Linux 4.3 By Altera 


My first test was to open /dev/ttyS0 via ssh. (stty -F /dev/ttyS0) 

Device was successfully opened and keystrokes successfully transmitted to the serial terminal 


But I was unable to open /dev/ttyS1 (stty -F /dev/ttyS1) with error 

stty: /dev/ttyS1: input/output error 


In /proc/tty/driver/serial I have: 

serinfo:1.0 driver revision: 0: uart:16550A mmio:0xFFC02000 irq:35 tx:10401 rx:724 RTS|DTR 1: uart:unknown mmio:0xFFC03000 irq:36  


Output of Linux starting: 

Serial: 8250/16550 driver, 2 ports, IRQ sharing disabled ffc02000.serial0: ttyS0 at MMIO 0xffc02000 (irq = 35, base_baud = 6250000) is a 16550A  

but no information about ttyS1. 


Its seems that ttyS1 is not connected to UART1. 


How can I activate /dev/ttyS1? 




In precompiled SD-card image from terrasic 

there is same problem 

But in image from rocketboards 

UART1 works well! 


Thanks. Sorry for my english
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