Master Control Registers
74 – CIO Chip
VL-486-4 Reference Manual
Master Control Registers
The master control registers consist of the Master Interrupt Control register and Master
Configuration Control register. These registers provide primary controls for the interrupt logic,
port and counter/timer enable bits, port and counter/timer link bits and the RESET bit.
M
ASTER
I
NTERRUPT
C
ONTROL
R
EGISTER
CIOMIC (READ/WRITE) 00H
D7
D6
D5
D4
D3
D2
D1
D0
MIE
DLC
NV
PAVIS
PBVIS
CTVIS
1
RESET
The Master Interrupt Control register contains the primary control bits for the interrupt control
logic. When the CIO chip is reset, all bits in all device registers are forced to 0 except RESET,
which is set to 1. All bits in the Master Interrupt Control register are Read/Write.