Mapping onto Datapath Control
Relationship between register transfer and microoperations:
Register Transfer Microoperations
AC ? MBR AC ? RBUS (immediate),
AC + MBR ? AC AC ? ALU A (immediate),
MBUS ? ALU B (immediate),
ALU Result ? RBUS (immediate),
IR:0> ? MAR IR ? ABUS (immediate),
IR:0> ? PC IR ? ABUS (immediate),
1 ? Read/Write Read (immediate);
0 ? Read/Write Write (immediate);
1 ? Request Request (immediate);
Special microoperations for AC ? ALU and ALU Result ? RBUS
not strictly necessary since these connections can be hardwired