Command File
| ADDX instruction
clock clka 0 1 0 0
clock clkabar 1 0 1 1
clock clkb 0 0 0 1
clock clkbbar 1 1 1 0
vector ir ir3 ir2 ir1 ir0
vector state s1 s2 s3 s4
ana state entp ldma readdm ldtp ldacc bus2acc loading ir
V RESTART 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
V LOADDONE 1
V ENTER 1
V DMSEG 0
V IMSEG 0
V ir 1000
R
Simulation
Notice:
- The difference between ADD and ADDX is that ADDX fetches its operand
from the memory pointed to by the IX (not TP) register
- During ID, the MA is loaded with the address location in the IX (ENIX
and LDMA)
- During OF, the data in DM is loaded into the TP (READDM and LDTP)
- During EX the ACC is loaded with the result of the ALU operation, so
BUS2ACC is low while LDACC
- ADDX requires two operands and needs the value in the
TP so ENTP is asserted