gtps1m0vSystem Macros

$MASKC-Change the System Mask

Use this system macro to change fundamental characteristics of a system operation by changing the first byte of the current program status word (PSW). Input/output (I/O) interrupts, external interrupts, program event recording (PER) interrupts, and the dynamic address translation (DAT) mode may be enabled or disabled.

Format




Notes:

  1. mask keywords

  2. List of mask keywords

label
A symbolic name can be assigned to the macro statement.

ENABLE=mask | (mask,...)

DISABLE=mask | (mask,...)

WINDOW=mask | (mask,...)
These parameters result in the current system mask being saved at the location specified by the SAVEWORK parameter and its control bits being enabled or disabled accordingly as indicated by the mask keyword (or list of mask keywords) coded.

The WINDOW parameter stores the system mask, enables the mask keywords specified, and reloads it.

The ENABLE and DISABLE parameters do not reload the system mask. Setting the bits to one/zero enables/disables the associated facilities when the system mask is reloaded by the RESTORE parameter.

These parameters specify the type of masking required with mask keywords. Masking can be specified either by individual keywords or by a list of keywords enclosed within parentheses. Either ENABLE, DISABLE, or both can be specified. The WINDOW and RESTORE parameters cannot be used on the same invocation as the DISABLE and ENABLE parameters. The RESTORE and WINDOW parameters cannot be used together on the same invocation. The mask keywords are:

EXT
External interrupt mask

IO
Input/output interrupt mask

PER
Program event recording interrupt mask

DAT
Dynamic address translation mode mask. When this bit is set on, dynamic address translation is initiated. When this bit is set off, addresses are treated as real addresses.

The ENABLE and DISABLE parameters are mutually exclusive with the RESTORE and WINDOW parameters.

If a null list is specified [for example, WINDOW=()], the parameter is ignored.

RESTORE
Indicates a system mask should be loaded from an address specified by the SAVEWORK parameter. RESTORE is a positional parameter.

SAVEWORK
Specifies the 1-byte storage location for a system mask. The default location is CPSAVMSK. The address can be specified by a label or a register enclosed in parentheses. Register R0 cannot be used.

If both the ENABLE and DISABLE parameters are specified, the byte following the address specified by SAVEWORK is used as a work area.

Entry Requirements

Return Conditions

The system mask of the current PSW is set to the desired state.

Programming Considerations

Examples