Post by Lawrence on Jul 29, 2014 11:04:12 GMT
The following shows how many I/O lines are used on the S3, in case you want to investigate using an alternative board.
The Digilent board is currently available (07/2014) but may not be for much longer.
www.digilentinc.com/Products/Detail.cfm?Prod=S3BOARD
This list relates to the project as currently coded, but there are (for example) alternative ways of wiring in the switches and buttons which would use fewer lines, and you could drop the discrete LEDs and just rely on the VGA display for the various status lines.
Displays
8 Discrete LEDs #
8+4 4 x 7-segment displays #
5 VGA signal + sync #
Switches
12 Rotary switch scanning
8 Slide switches #
4 Pushbuttons #
4 Encoded switch inputs
8 Rotary switch inputs
Other I/O
2 Serial I/O #
3 Flash clock/control/data #
SRAM (256k x 9)
18 SRAM address #
5 SRAM CE/UB/LB/WE/OE #
9 SRAM data I/O #
# denotes items integrated onto the S3 Board.
I have an alternative LED/switch connection system which uses the following in place of the 32 LED/switch lines listed above:
8 Switch scans + inputs
6 LED drive via SPI
5 Discrete LED drives
However this is not yet supported by the VHDL
The Digilent board is currently available (07/2014) but may not be for much longer.
www.digilentinc.com/Products/Detail.cfm?Prod=S3BOARD
This list relates to the project as currently coded, but there are (for example) alternative ways of wiring in the switches and buttons which would use fewer lines, and you could drop the discrete LEDs and just rely on the VGA display for the various status lines.
Displays
8 Discrete LEDs #
8+4 4 x 7-segment displays #
5 VGA signal + sync #
Switches
12 Rotary switch scanning
8 Slide switches #
4 Pushbuttons #
4 Encoded switch inputs
8 Rotary switch inputs
Other I/O
2 Serial I/O #
3 Flash clock/control/data #
SRAM (256k x 9)
18 SRAM address #
5 SRAM CE/UB/LB/WE/OE #
9 SRAM data I/O #
# denotes items integrated onto the S3 Board.
I have an alternative LED/switch connection system which uses the following in place of the 32 LED/switch lines listed above:
8 Switch scans + inputs
6 LED drive via SPI
5 Discrete LED drives
However this is not yet supported by the VHDL