Timers Block – Part Three

On the previous entries of this series we already commented about:

In this third part of the series (as promised), we will show how to implement the timers block by using, not registers, but memory blocks.

Memory blocks are an often unused capability of modern FPGAs and can in many cases (as in this one) be a nice alternative to save on scarce resources like registers and LUTs. As we commented in the previous entry, implementing a block of 32 x 16 bit timers took about 7% of the LUTs of a Cyclone, and we wanted to see if we can reduce the quantity of resources taken.

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MIF_Gen – A Matlab Utility

matlab_mif_gen

Many times I find myself in the need of generating data for testing. We need data for verification, either done on simulation or on the real target.

One easy way to test our system is to generate data vectors on RAM. Altera RAM IP includes the ability to initialize RAM contents during power-up by means of a .hex file.

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Introducing the Spartan 3E FPGA and VHDL – free book

spartan3EAuthor Mike Fields wrote this book as an introduction to FPGAs and VHDL. The book examples are mainly oriented to Xilinx Spartan 3E FPGA (but as in other books, the concepts are general. If you don’t have that FPGA, adapting the book examples to your own device can be an excellent way to learn).

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BeMicro CV – HW & SW LED flasher

The second project for the BeMicro CV board will be a HW/SW LED flasher. From the LEDs present in the board, some will be flashed by HW, and others will be flashed by SW running on a NIOS processor.

For an introduction about the Be Micro CV evaluation board, please refer to this post.

What will the project do:

  1. Flash a sequence of HW LEDs by dividing the clock input
  2. Make a ‘lamp test’ (all LEDs lit) when reset is pressed
  3. LEDs sequence is accelerated if the user presses the second push button on the board.
  4. Three LEDs are flashed by SW. To differentiate between the two groups, the LEDs flashed by SW run faster.

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BeMicro CV – HW LED flasher

The first in the projects for the BeMicro CV board will be a HW LED flasher. Although the design is very easy, it is a complete design including absolutely all the elements needed to achieve a reliable design with timing closure.

For an introduction about the Be Micro CV evaluation board, please refer to this post.

What will the project do:

  1. Flash a sequence of LEDs by dividing the clock input
  2. Make a ‘lamp test’ (all LEDs lit) when reset is pressed
  3. LEDs sequence is accelerated if the user presses the second push button on the board.

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VHDL Arbiter – part II

In the previous installment, we defined what a HW arbiter is. Let’s see a simple implementation of a VHDL arbiter.

The arbiter has three inputs and three outputs.

The logic is very simple. If the first master (master 0) asserts a request, it is awarded grant. Master 1 is given grant only if it requests the bus and master 0 doesn’t request the bus.

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