Embedded Systems

There are no tutorials explaining the use of BSCAN_SPARTAN3 primitive on Xilinx FPGAs. It's a very useful feature, which allows to literally establish a PC-to-FPGA link over a JTAG adapter. This primitive is already used in projects such as xc3sprog and Papilio-Loader to program SPI flash memory over JTAG.

BSCAN_SPARTAN3 …

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The following setup was used for Basys2 board with an external FTDI-based JTAG adapter. Read the previous posts to get familiar with setup.

Specifying USERCODE

User code register provides bit stream identification and a type of version control. To write a user code into a bit stream in Xilinx ISE, …

In order to program Basys2 board using xc3sprog and FTDI-Based JTAG Adapter, learn positions of the devices in the chain:

UrJTAG is a good low-level tool to learn boundary scan operations and play with EXTEST, INTEST instructions. Assuming that the Basys2 board is connected to a UM232H-based JTAG adapter as described in the previous article, we can test EXTEST and INTEST instructions. Note that depending on package (VQ100, CP132, …

I had a task to check whether OpenOCD can program a Spartan 3 series FPGA by means of FTDI-MPSSE-based JTAG adapter. There wasn't any chip available in my hands, so I had to experiment with existing hardware. I decided to solder the FTDI-based adapter to a Basys2 development board. The …