DEC KA681, System Maintenance

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Data Structures and Memory Layout
D.1 Halt Dispatch State Machine
Table D–1 (Cont.) Firmware State Transition Table
Current
State Next
State Halt
Type Halt
Code
Mailbx
Action
User
Action HEN-ERR-TIP-
DIP-BIP-RIP
INIT –>RESTART xxx 1x 00 001 x - 0 - 0 - 0 - 0
- 0
INIT –>RESTART xxx 1x 00 100 x - 0 - 0 - 0 - 0
- 0
INIT –>RESTART xxx 1x 00 000 0 - 0 - 0 - 0 - 0
- 0
Perform common exit processing, if
no errors.
7
BOOTSTRAP –>EXIT xxx xx xx xxx x - 0 - x - x - x
- x
RESTART –>EXIT xxx xx xx xxx x - 0 - x - x - x
- x
HALT –>EXIT xxx xx xx xxx x - 0 - x - x - x
- x
Exception transitions, just halt.
8
INIT –>HALT xxx xx xx xxx x - x - x - x - x
- x
BOOT –>HALT xxx xx xx xxx x - x - x - x - x
- x
REST –>HALT xxx xx xx xxx x - x - x - x - x
- x
HALT –>HALT xxx xx xx xxx x - x - x - x - x
- x
TRACE –>HALT xxx xx xx xxx x - x - x - x - x
- x
EXIT –>HALT xxx xx xx xxx x - x - x - x - x
- x
7
Exit after halts, bootstrap or restart. The exit state transitions to program I/O mode.
8
Guard block that catches all exception conditions. In all cases, just halt.
Data Structures and Memory Layout D–5