T Able 8-1: Or Logic; Table 8-2: Mode Register - Complete Overview; Table 8-3: Mode Register - Partial Overview; Interrupt Control - Addi-Data PC104-PLUS1500 Technical Description

Functions of the board

Interrupt control

The interrupt logic is blocked after triggering an interrupt. It is released again at
the end of the interrupt routine. In the interrupt routine the boards does not react
on changes of the input channels. A further interrupt is generated if an
interruptible edge or status change occurs. A new interrupt is firstly possible after
the completion of the original interrupt service routine.
OR logic
Mode_1
Mode_2
The OR logic reacts to rising or falling edges.
An interrupt is triggered if at an interruptible input an edge switch occurs that
fulfils the interrupt condition, which is set by Mode_1 and Mode_2.
D31....
Mode_1
Mode_2
Example:
Mode_1 = 0x0000000C
Mode_2 = 0x00000008
In the figure below the following parameters are set:
1. Condition: Channels 2 and 3 react to rising edges
(Mode_1 = 11).
2. Condition: Channels 2 and 3 react to falling edges
(Mode_2 = 11).
34
Table 8-1: OR logic
Disable
0
0
Table 8-2: Mode register – Complete overview
D5
Table 8-3: Mode register – partial overview
Channel 3
rising
Channel 3
falling
// Release rising edge (channel 2 to 3)
hex
// Release falling edge (channel 3)
hex
Rising Falling Rising/falling
1 0 1
0 1 1
D4 D3
Channel 3 Channel 2
Channel 3 Channel 2
Is not used:
Channel 2
rising
Channel 2
falling
PC104-PLUS1500
D2 D1 D0