dsp56800e Freescale Semiconductor, Inc, dsp56800e Datasheet - Page 293

• Manufacturer Part Number: dsp56800e
• Description: 16-bit Digital Signal Controller Core
• Manufacturer: Freescale Semiconductor, Inc

10.3.5
Figure 10-5 shows the program flow, and the corresponding pipeline, during fast interrupt processing.
Within the pipeline, ii0 refers to the first instruction word in the fast interrupt handler, and ii4 refers to the
FRTID instruction. The instructions ii5 and ii6 are the 2 instruction words filling the FRTID’s delay slots.
Freescale Semiconductor
i = Interrupt Arbitration and Request
ii = Interrupt instruction word
n = Normal instruction word
Pipeline
Int Arbitr
Int Req
Stage
OP2
EX2
AG
EX
P1
P2
ID
IF
Fast Interrupt Processing Pipeline
n1 n2 n3 n4 ii0 ii1 ii2 ii3 ii4 ii5
1
Program
n1 n2 n3 n4 ii0 ii1 ii2 ii3 ii4
2
Main
n1
n2
n1 n2 n3 n4 ii0 ii1 ii2 ii3
3
i
n1 — — — ii0 ii1 ii2
4
i
Interrupt Requests Sampled
n1 — — — ii0 ii1
5
Figure 10-5. Fast Interrupt Processing
n1 — — — ii0
6
by the Arbiter
n1 — — —
7
Fast Interrupt
n1 — —
Return From
8
(b) Interrupt Pipeline
(a) Instruction Flow
Instruction Pipeline
(FRTID)
Explicit
9 10 11
Instruction Cycle
ii6
ii5
ii4
ii3
ii2
ii1
ii0
—
12
di0
ii7
ii6
ii4
ii3
ii2
ii1
ii0
frtid
di0
13
di1
n2
ii7
ii3
ii2
ii1
frtid
Pipeline During Interrupt Processing
di1
di0
14
n3
n2
ii7
ii3
ii2
Vector Table
Interrupt
FRTID
frtid
di1
15
di0
n3
n2
—
ii3
di0
di1
ii0
ii1
ii2
ii3
•
frtid
di1
di0
16
n3
n2
—
•
•
Fast Interrupt
di1
di0
17
n3
n2
Subroutine
—
•
•
•
PC Resumes
Operation
di1
18
n3
n2
—
•
•
•
•
19 20 21
n3
n2
—
•
•
•
•
•
n3
n2 n3
•
•
•
•
•
•
•
•
•
•
•
•
•
10-13