Computer Hardware User's Guide

Write must
complete
before the
two reads can
complete
2 reads
performed
Pipeline Conflicts
8-13
Pipeline Operation
Example 8–8. Single Store Followed by Two Reads
STFR 0,*AR1 ; R0 *AR1
LDF *AR2,R1 ; *AR2 R1 in parallel with
 LDF *AR3,R2 ; *AR3 R2
Pipeline Operation
PC Fetch
Decode Read Execute
n STF
n+1 LDFLDF STF
n+2 W LDFLDF STF
n+3 X W LDFLDF STF
n+4 X W LDFLDF (nop)
n+4 Y X W LDFLDF
Note: W, X, Y = Instruction representations