|
|
Privileged Mode
Modifies the NM processor status word (PSW).
Exercise a bit of care with this command.
Syntax
MPSW bit_string
Parameters
- bit_string
A string of characters that indicates which bits in the PSW are to be
modified. The letters listed below represent individual fields: lower
case implies turn the bit off, and uppercase implies turn the bit on. All
unreferenced bits remain unchanged. All named bits with the exception of
the "C/B" bits may be altered with this command. The IPSW has the
following format:
1 1 1 1 1 1 1 2 2 2 2 3 3
0 7 8 9 0 1 2 3 4 5 6 4 7 8 9 0 1
------------------------------------------------------------
|J| |T|H|L|N|X|B|C|V|M| C/B | |R|Q|P|D|I|
------------------------------------------------------------
- J
Joint instruction and data TLB misses/page faults pending
- T
Taken branch trap enabled
- H
Higher-privilege transfer trap enable
- L
Lower-privilege transfer trap enable
- N
Instruction whose address is at front of PC queue is nullified
- X
Data memory break disable
- B
Taken branch in previous cycle
- C
Code address translation enable
- V
Divide step correction
- M
High-priority machine check disable
- C/B
Carry/Borrow bits
- R
Recovery counter enable
- Q
Interruption state collection enable
- P
Protection ID validation enable
- D
Data address translation enable
- I
External, power failure, & low-priority machine check
interruption enable
System Debug displays this register in two formats:
IPSW=$6ff0b=jthlnxbCVmrQpDI
The first value is a full 32-bit integer representation of
the register. The second format shows the value of the special named
bits. An uppercase letter means that the bit is on while a lowercase
letter indicates that the bit is off.
Examples
%nmdebug > dr psw
PSW=0006ff0f=jthlnxbCVmrQPDI
%nmdebug > mpsw p
%nmdebug > dr psw
PSW=0006ff0b=jthlnxbCVmrQpDI
Turn OFF the protection ID validation enable bit in the IPSW.
$nmdat > mpsw CD
$nmdat >
Enable code and data translation. System Debug windows are affected by these
two bits.
Limitations, Restrictions
NMdebug alters the "R" bit while single stepping and the "T" bit when the
TRAP BRANCH command is used.
The system dispatcher enforces fixed settings for several key bits. For
example, if the "I" bit is turned off with this command,
the dispatcher sets it back on when this process is launched.
|