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Raven Interrupt Controller Implementation
http://www.motorola.com/computer/literature
2-69
2
External Source Vector/Priority Registers
MASK MASK. Setting this bit disables any further interrupts from this
source. If the mask bit is cleared while the bit associated with this interrupt
is set in the IPR, the interrupt request will be generated.
ACT ACTIVITY. The activity bit indicates that an interrupt has been
requested or that it is in-service. The ACT bit is set to a one when its
associated bit in the Interrupt Pending Register or In-Service Register is
set.
POL POLARITY. This bit sets the polarity for external interrupts.
Setting this bit to a zero enables active low or negative edge. Setting this
bit to a one enables active high or positive edge. Only External Interrupt
Source 0 uses this bit in this register.
SENSE SENSE. This bit sets the sense for external interrupts. Setting this
bit to a zero enables edge sensitive interrupts. Setting this bit to a one
enables level sensitive interrupts. For external interrupt sources 1 through
15, setting this bit to a zero enables positive edge triggered interrupts.
Setting this bit to a one enables active low level triggered interrupts.
PRIOR Interrupt priority 0 is the lowest and 15 is the highest. Note that a
priority level of 0 will not enable interrupts.
Offset
Int Src 0 - $10000
Int Src 2 -> Int Src15 - $10020 -> $101E0
Bit
3
1
3
0
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
1
0 9 8 7 6 5 4 3 2 1 0
Name
EXTERNAL SOURCE VECTOR/PRIORITY
MAS
K
AC
T
PO
L
SE
NS
E
PRIOR
VECTOR
Operation
R/
W
R
R
R/
W
R/
W
R
R
R/W
R
R/W
Reset
1
0
$000
0
0
0
0
$0
$00
$00