Description of the LED's on the front panel of PB and RootBoard
LED's of the Processing Board:
Arrangement:
SW SR EX
(green) (yellow) (red)
RS RM HL
(green) (yellow) (red)
Meaning:
- SW = System Write
Is on when devices, like memories or registers of the PB are
written in system mode
- SR = System Read
Is on when devices, like memories or registers of the PB are
read in system mode
- EX = Exception
Is on when a HW exception as occurred (i.e. when a non-masked
bit of any exception register is set)
- RS = RUN-mode / SYSTEM-mode
Is on when the PB is in RUN-mode
- RM = Remote
Is on when remote memory accesses (communications) are performed
- HL = Halt
Is on when the PB is in HALT status (i.e. after encountering the
HALT instruction, e.g. at the beginning of an IO operation)
LED's of the RootBoard:
Arrangement:
RN MR EX
(green) (yellow) (red)
CR TR HL
(green) (yellow) (red)
Meaning:
- RN = Run
Is on when the machine is in RUN-mode
- MR = Master Root
Is on when the machine is running as a multi-tower system
- EX = Exception
Is on when a HW exception has occurred on any of the boards
- CR = Crate Root
Is on when the machine is running as an APEcrate system
- TR = Tower Root
Is on when the machine is running as a multi-crate system
- HL = Halt
Is on when the machine is in HALT status
