VULCAN Technical Manual
Detailed hardware description
© 2007 Eurotech Ltd Issue D
30
General purpose I/O
Eight general-purpose inputs and eight general-purpose output lines are provided on
connector J3, using memory mapped register located on the expansion bus (CS4#) at
address offset 0x04000000 (0x54000000). The general purpose inputs are 5V tolerant,
and the outputs can sink and source up to 24mA @ 3.3V.
The following table shows the bit definitions:
Bits Description
7:0
IN[7:0]: GP inputs on read access.
OUT[7:0]: GP outputs on write access.
Hex Offset Address:
0x04000000
Reset Hex Value:
0x00
Access:
Read/write
This is illustrated by the following diagram:
IXP425
Buffer
J3
D[0:7]
IN[0:7]
3.3V
10k
ohms
OUT[0:7]
Register
D[0:7]
OUT[0:7]
IN[0:7]
