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MicroBlaze Processor Reference Guide
UG081 (v14.7)
Chapter 5:
MicroBlaze Instruction Set Architecture
brk
Break
Description
Branch and link to the instruction located at address value in rB. The current value of PC will be
stored in rD. The BIP flag in the MSR will be set, and the reservation bit will be cleared.
When MicroBlaze is configured to use an MMU (C_USE_MMU >= 1) this instruction is privileged.
This means that if the instruction is attempted in User Mode (MSR[UM] = 1) a Privileged
Instruction exception occurs.
Pseudocode
if MSR[UM] = 1 then
ESR[EC]
←
00111
else
(rD)
←
PC
PC
←
(rB)
MSR[BIP]
← 1
Reservation
← 0
Registers Altered
•
rD
•
PC
•
MSR[BIP]
•
ESR[EC], in case a privileged instruction exception is generated
Latency
•
3 cycles
brk
rD, rB
1 0 0 1 1 0
rD
0 1 1 0 0
rB
0 0 0 0 0 0 0 0 0 0 0
0
6
11
16
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