Method and apparatus for servicing simultaneous I/O trap and debug traps in a microprocessor
US5745770A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 1, 1996 |
| Grant date | Apr 28, 1998 |
| Priority date | — |
| Expiry date | Feb 1, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D10/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A microprocessor includes the capability to service at least one debug exception and an I/O trap generated during execution of a single instruction. After executing each instruction, the microprocessor determines whether a debug exception and an I/O trap occurred. If at least one debug exception and an I/O trap exist, then the microprocessor determines an active status for the debug exception. The microprocessor stores the contents of internal registers, constituting a state of the microprocessor, to memory, and latches a breakpoint status for the debug exception in a public debug status register. The breakpoint status is preserved by copying the breakpoint status to a private debug status register. The microprocessor services the I/O trap by executing a SMM handler, an upon returning from the SMM handler, the state of the microprocessor is restored. If the I/O trap serviced requires instruction restart, then the state of the microprocessor is adjusted to re-execute the instruction. The microprocessor copies the breakpoint status, stored in the private debug status register, to the public debug status register when the I/O trap does not require instruction restart. The debug except…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.