View source for FPGA Controller for LED Matrix

[[Category:Closed_Projects]]

A FPGA-based interface controller for
[http://www.limpkin.fr/index.php?post/2011/05/12/Oops...-I-dit-it-again%21 Limpkin's RGB LED matrices].


=== Matrix reference ===

[[LedMatrix]]

== Overview ==

* FPGA drives 1 or more (up to 4?) matrices
* use block ram or external SRAM for frame buffer storage
* interface with PC


=== Feature ideas ===

* double buffering
* larger off-screen buffer + compositing ops?
* character generation
* update only sections
* small CPU core to execute short programs?


== Components ==

=== Memory ===

External SRAM needs to be fast enough to handle all reads during one
cycle.  Per connected matrix we need to read 6 bytes per cycle.
Clearly this would require use to run at 150MHz, which is infeasible.
If we use a separate chip per matrix block (6 chips or 3 chips with
16bit width), we can still operate with 25MHz.

Concurrent writes need to be possible, but at a lower speed.  Either
buffer reads and slip in writes when there is slack (complicated), or
alternate between reads and writes at higher speed (DDR?).