Visible to Intel only — GUID: iga1401317112762
Ixiasoft
Visible to Intel only — GUID: iga1401317112762
Ixiasoft
12.1. Core Overview
The JTAG UART core with Avalon® interface implements a method to communicate serial character streams between a host PC and a Platform Designer system on an Intel FPGA. In many designs, the JTAG UART core eliminates the need for a separate RS-232 serial connection to a host PC for character I/O. The core provides an Avalon® interface that hides the complexities of the JTAG interface from embedded software programmers. Host peripherals (such as a Nios® II and Nios® V processors) communicate with the core by reading and writing control and data registers.
The JTAG UART core uses the JTAG circuitry built in to Intel FPGAs, and provides host access via the JTAG pins on the FPGA. The host PC can connect to the FPGA via any Intel FPGA JTAG download cable, such as the Intel FPGA download cable II. Software support for the JTAG UART core is provided by Intel. For the Nios® II and Nios® V processors, device drivers are provided in the hardware abstraction layer (HAL) system library, allowing software to access the core using the ANSI C Standard Library stdio.h routines.
Nios® II processor users can access the JTAG UART via the Nios® II IDE or the nios2-terminal command-line utility. For Nios® V processor users, you can access the JTAG UART using the juart-terminal command-line utility. For further details, refer to the Nios II Software Developer Handbook or the Nios® II IDE online help.
For the host PC, Intel provides JTAG terminal software that manages the connection to the target, decodes the JTAG data stream, and displays characters on screen.