Here's a draft of where I think LEDs should go. It also outlines
which peripherals we plan to change from M1rc3 to M1r4:
Peripheral LEDs Comment
M1rc3 M1r4
--------------- --------------- ------ ---------------------------------------
2 USB (ext) 4 USB (ext) 4
3 button 1 button -
3 LED (stat) 1 LED (stat) (1) maybe off-matrix; one LED moves to DC
1 IR = 1 still needs testing for interference
2 Audio = 2
1 Microphone = 1
1 VGA 1 DVI-I 1
1 DC in = (1) off-matrix, with special circuit
1 Ethernet = - receptacle has two built-in LEDs
3 Video in = 3
2 MIDI = 2
2 DMX = 2
1 Memory card = -
- 2 USB (int) -
------
16+2
The DC in LED that's currently in a bank with two other status LEDs
would move to the power connector. For those M1 users living in
areas with frequent bombing raids, Wolfgang also wants a way for
software to disable this LED, so that one can black out the M1
completely. This will require one dedicated I/O line.
Of the remaining two status LEDs ("booted" and "rendering"), only
one would stay. It may be useful to have a dedicated I/O line for
this LED too, since this will allow closer monitoring of the boot
process. E.g., the "dimly lit" condition that indicates that the
FPGA failed to configure.
All the other LEDs would be in the LED matrix. With 16 LEDs, we
could use a 2*4*2 matrix (using 6 I/Os), but I think we should
leave some room for extensions and make the matrix either 3*3*2
(also 6 I/Os) or 3*4*2 (7 I/Os).
The proof of concept LED board I built uses a 3*4*2 matrix. The LED
matrix controller can be build-time configured for any of the above
structures.
Nobody seem to feel a great need for having LEDs on the memory card
connector (nearly inaccessible anyway) or on the internal USB ports.
So I left those without LED.
- Werner
_______________________________________________
http://lists.milkymist.org/listinfo.cgi/devel-milkymist.org
IRC: #milkymist@Freenode
