Embedded Peripherals IP User Guide

ID 683130
Date 10/24/2025
Public
Document Table of Contents
1. Introduction 2. Avalon® -ST Serial Peripheral Interface Core 3. SPI Core 4. SPI Agent/JTAG to Avalon® Host Bridge Cores 5. Intel eSPI Agent Core 6. eSPI to LPC Bridge Core 7. Ethernet MDIO Core 8. Intel FPGA 16550 Compatible UART Core 9. UART Core 10. Lightweight UART Core 11. JTAG UART Core 12. Intel FPGA Avalon® Mailbox Core 13. Intel FPGA Avalon® Mutex Core 14. Intel FPGA Avalon® I2C (Host) Core 15. Intel FPGA I2C Agent to Avalon® -MM Host Bridge Core 16. EPCS/EPCQA Serial Flash Controller Core 17. Intel FPGA Serial Flash Controller Core 18. Intel FPGA Serial Flash Controller II Core 19. Intel FPGA Generic QUAD SPI Controller Core 20. Intel FPGA Generic QUAD SPI Controller II Core 21. Interval Timer Core 22. Intel FPGA Avalon FIFO Memory Core 23. On-Chip Memory (RAM and ROM) Intel FPGA IP 24. On-Chip Memory II (RAM or ROM) Intel FPGA IP 25. PIO Core 26. PLL Cores 27. DMA Controller Core 28. Modular Scatter-Gather DMA Core 29. Scatter-Gather DMA Controller Core 30. Video Sync Generator and Pixel Converter Cores 31. Intel FPGA Interrupt Latency Counter Core 32. Performance Counter Unit Core 33. Vectored Interrupt Controller Core 34. System ID Peripheral Core 35. Intel FPGA GMII to RGMII Converter Core 36. HPS GMII to RGMII Adapter IP 37. Intel FPGA MII to RMII Converter Core 38. HPS GMII to TSE 1000BASE-X/SGMII PCS Bridge Core IP 39. Intel FPGA HPS EMAC to Multi-rate PHY GMII Adapter Core 40. Intel FPGA MSI to GIC Generator Core 41. Cache Coherency Translator IP 42. Altera ACE5-Lite Cache Coherency Translator

9.4.1.2. ioctl() Operations

The UART driver supports the ioctl() function to allow HAL-based programs to request device-specific operations. The table below defines operation requests that the UART driver supports.

Table 86.  UART ioctl() Operations
Request Description
TIOCEXCL Locks the device for exclusive access. Further calls to open() for this device will fail until either this file descriptor is closed, or the lock is released using the TIOCNXCL ioctl request. For this request to succeed there can be no other existing file descriptors for this device. The parameter arg is ignored.
TIOCNXCL Releases a previous exclusive access lock. The parameter arg is ignored.

Additional operation requests are also optionally available for the fast driver only, as shown in Optional UART ioctl() Operations for the Fast Driver Only Table. To enable these operations in your program, you must set the preprocessor option -DALTERA_AVALON_UART_USE_IOCTL.

Table 87.  Optional UART ioctl() Operations for the Fast Driver Only
Request Description
TIOCMGET Returns the current configuration of the device by filling in the contents of the input termios structure. 
A pointer to this structure is supplied as the value of the parameter opt.
TIOCMSET Sets the configuration of the device according to the values contained in the input termios structure. 
A pointer to this structure is supplied as the value of the parameter arg.
Note: The termios structure is defined by the Newlib C standard library. You can find the definition in the file <Nios II EDS install path>/components/altera_hal/HAL/inc/sys/termios.h.

For details about the ioctl() function, refer to the Nios II Software Developer's Handbook .