FUJITSU Implementation Supplement Fujitsu SPARC64 V - Manual (Page 150)

Release 1.0, 1 July 2002 F. Chapter O Reset, RED_state, and error_state 139
O.2 RED_state and error_state
FIGURE O-1 illustrates the processor state transition diagram.
FIGURE O-1 Processor State Diagram
exec_state RED_state
error_state **
DONE/RETRY
RED = 0
TRAP@MAXTL–1
SIR@
TRAP
RED = 1
TRAP@MAXTL
SIR@MAXTL
TRAP@
SIR@
TRAP@MAXTL
SIR@MAXTL @
POR
WDT1*
WDT2**
XIR
Any State
Including Power Off
@
WDT1@MAXTL–1
WDT1@
WDT1@MAXTL
WDT2*
ErrorState trans Error
CPU Fatal
Error ***
Fatal Error
Fatal Error
* WDT1 is the first watchdog timeout.
** WDT2 is the second watchdog timeout. WDT2 takes the CPU into error_state . In a normal setting,
error_state immediately generates a watchdog reset trap and brings the CPU into RED_state . Thus, the
state is transient. When OPSR (Operation Status Register) specifies the stop on error_ state , an entry into
error_state does not cause a watchdog reset and the CPU remains in the error_state .
*** CPU_fatal_error_state signals the detection of a fatal error to the system through P_FERR signal to the sys-
tem, and the system causes a FATAL reset. Soft POR will be applied to the all CPUs in the system at the FATAL
reset.
WDR