Intel
®
81341 and 81342—Inter-Processor Messaging Unit
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
828
Order Number: 315037-002US
13.4
Interrupts
The IMU can generate two interrupts (one per Intel XScale
®
processor) for the
assertion of Send Queue or Receive Queue Not Full or Not Empty conditions,
respectively. In addition, the interrupt may be asserted when any of the 15 Door Bell
Status bits are set by the other processor. The IMU has one interrupt output connected
to the Interrupt Controller Unit for each core described in
Chapter 4, “Interrupt
Controller Unit”
.
summarizes the status flags and conditions when interrupts
are generated in the Door Bell Control Register (DBCR).
Table 505. IMU Interrupt Summary
Interrupt Condition
Door Bell Control Register Flags
Re
ce
ive
Q
ue
ue
3
No
t E
mp
ty
Se
nd
Q
ue
ue
3
No
t F
ull
Re
ce
ive
Q
ue
ue
2
No
t E
mp
ty
Se
nd
Q
ue
ue
2
No
t F
ull
Re
ce
ive
Q
ue
ue
1
No
t E
mp
ty
Se
nd
Q
ue
ue
1
No
t F
ull
Re
ce
ive
Q
ue
ue
0
No
t E
mp
ty
Se
nd
Q
ue
ue
0
No
t F
ull
Do
or
Be
ll S
tat
us
(1
4:0
)
Receive Queue 3 Not Empty
a
(RQ3NE)
a. Empty Condition is (Put Pointer = Get Pointer)
1
0
0
0
0
0
0
0
0
Send Queue 3 Not Full
b
(SQ3NF)
b. Full Condition is (Put Pointer — Get Pointer = Size)
0
1
0
0
0
0
0
0
0
Receive Queue 2 Not Empty
(RQ2NE)
0
0
1
0
0
0
0
0
0
Send Queue 2 Not Full
(SQ2NF)
0
0
0
1
0
0
0
0
0
Receive Queue 1 Not Empty
(RQ1NE)
0
0
0
0
1
0
0
0
0
Send Queue 1 Not Full
(SQ1NF)
0
0
0
0
0
1
0
0
0
Receive Queue 0 Not Empty
(RQ0NE)
0
0
0
0
0
0
1
0
0
Send Queue 0 Not Full
(SQ0NF)
0
0
0
0
0
0
0
1
0
Door Bell Status! = 0
0
0
0
0
0
0
0
0
See
Note
c
c. Appropriate bits in Door Bell Status (14:0) are set depending on which door bells the other processor set in
its’ Door Bell Assert Register.