Program Status Word: Difference between revisions

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| [[Machine check]] mask
| [[Interrupts#Machine Check Interrupt|Machine Check Interrupt]] mask
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| PSW Key for complex memory protection
| PSW Key for [[Complex Memory Protection|complex memory protection]]
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| [[External interrupt]] mask
| [[Interrupts#External Interrupt|External Interrupt]] mask
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| [[Input/Output interrupt]] mask
| [[Interrupts#Input/Output Interrupt|Input/Output Interrupt]] mask
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| [[Enable program event recording]]
| [[Program Event Recording|Enable program event recording]]
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=== External links ===
=== External links ===
* https://www.kernel.org/doc/html/v5.3/s390/debugging390.html Contains the structure of the PSW (in MSB order)
* https://www.kernel.org/doc/html/v5.3/s390/debugging390.html Contains the structure of the PSW (in MSB order)

[[Category:S390]]

Revision as of 18:40, 15 October 2021

The PSW (Program Status Word) describes the current configuration for the context. It control whenever DAT is enabled or not, which allows virtual spaces. It also controls several flags such as the Wait state, Problem state, interrupt masking and other essential execution parameters.

While the 390 documentation lists the PSW in Most-Significant-Bit order, the PSW listed here will be in Least-Significant-Bit order for simplicity.

Bits Name
0 Extended addressing mode (z/Arch only)
1-7 Reserved
8 Unknown (?)
9 Enable exception for Exponent Underflow
10 Enable exception for Decimal Overflow
11 Enable exception for Fixed Point Overflow
12-13 Condition code
14-15 Address space control
16 Problem state (1=Disables unprivileged instruction execution)
17 Wait state (Wait for interrupt)
18 Machine Check Interrupt mask
19 1=S390, 0=z/Arch
20-23 PSW Key for complex memory protection
24 External Interrupt mask
25 Input/Output Interrupt mask
26 Enable DAT
27-29 Reserved
30 Enable program event recording
31 Reserved and must be 0

See also

External links