User`s guide

Configurable Machine State
8: IO2 ID enable
1 = enabled
7: Force wrong CP2 bus parity - off - diagnostic use only
6: Force wrong CP1 bus parity - off - diagnostic use only
5: Force wrong NDAL master parity - off - diagnostic use
only
4: Force wrong NDAL slave parity - off - diagnostic use
only
3: Enable prefetch
1 = enable CP bus prefetch on DMA reads
2: Force write buffer hit - off - diagnostic use only
1: Force CP2 bus owner - diagnostic use only
0 = disabled
0: Force CP1 bus owner - diagnostic use only
0 = disabled
ICCS: Interval Clock Control and Status Register (2100 0060)
NOTE: OpenVMS sets ICCS, NICR to proper values.
6: Interrupt enable
0 = disabled*
5: Single step - off
4: Transfer
0 = disabled*
0: Run - increment every 1usec - off
NICR: Next Interval Count Register (2100 0064)
31:0 Initial count value for ICR (FFFFD8F0* (10ms))
NMC:
-----
NMC_CSR0-7: Memory Configuration Registers (2101 8000 thru 2101 801C)
NOTE: Diagnostics set these registers based on available memory
31: Base Address Valid
0 = not valid*
1 = valid
28:24: Base Address (0 on reset)
1MB RAM - all address bits used
4MB RAM - only <28:26> used
2:1 RAM size
01 = 1MB RAM
10 = 4MB RAM
11 = non-existent bank
0: Mode
1 = 64-bit mode
NMC_CSR18: Mode Control and Diagnostic Status Register (2101 8048)
31: Fast Diagnostic Mode (FDM)
0 = disabled* - diagnostic use only
30: FDM Second pass
0 = disabled* - diagnostic use only
D–2 Configurable Machine State