Fujitsu Fujitsu SPARC64 V manual Restrainable Error, Traps for Urgent Errors

Models: Fujitsu SPARC64 V

1 255
Download 255 pages 53.5 Kb
Page 163
Image 163

When the resource with the error is used, the program cannot continue execution, or the error_state transition error or the fatal error is detected.

The error in an important resource that is expected to invoke the operating system “panic” process

The operating system panic process is expected when this error is detected because the normal processing cannot be expected to continue when this error occurs.

The A_UGE is a disrupting error with the following deviations.

The trap for A_UGE is not masked by PSTATE.IE.

The instruction designated by TPC may not end precisely. The instruction end- method is reported in the trap status register for A_UGE.

Traps for Urgent Errors

When an urgent error is detected and not masked, the error is reported to privileged software by the following exceptions:

I_UGE, A_UGE: async_data_error exception

IAE:instruction_access_error exception

DAE:data_access_error exception

P.1.4 Restrainable Error

A restrainable error is one that does not adversely affect the currently executing program and that does not require immediate handling by privileged software. A restrainable error causes a disrupting trap with low priority.

There are three types of restrainable errors.

Correctable Error (CE), corrected by hardware

Upon detecting the CE, the hardware uses the data corrected by hardware. So a CE has no deleterious effect on the CPU.

When a CE is detected, data seen by the CPU has always already been corrected by hardware, but it depends on the CE type whether the original data containing the CE is corrected or not.

Uncorrectable error without direct damage to the currently executing instruction sequence.

An error detected in cache line writeback or copyback data is of this type.

152 SPARC JPS1 Implementation Supplement: Fujitsu SPARC64 V • Release 1.0, 1 July 2002

Page 163
Image 163
Fujitsu Fujitsu SPARC64 V manual Restrainable Error, Traps for Urgent Errors, Correctable Error CE, corrected by hardware