Bug 338

Summary: CompUnitALU needs go_die to be wired to ALU shadow mask
Product: Libre-SOC's first SoC Reporter: Luke Kenneth Casson Leighton <lkcl>
Component: Source CodeAssignee: Luke Kenneth Casson Leighton <lkcl>
Status: CONFIRMED ---    
Severity: enhancement CC: libre-soc-bugs
Priority: ---    
Version: unspecified   
Hardware: PC   
OS: Mac OS   
See Also: https://bugs.libre-soc.org/show_bug.cgi?id=305
NLnet milestone: NLnet.2019.02.012 total budget (EUR) for completion of task and all subtasks: 0
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Bug Blocks: 81    

Description Luke Kenneth Casson Leighton 2020-05-22 17:16:20 BST 
this is for ALU cancellation.  when go_die is pulled on a Comp Unit, it indicates
that the result - computed or in transit to *be* computed - is no longer required
and must be dropped on the floor, immediately.

ALU pipelines are to be set up with "cancellation" capability.  this is set
from nmutil.concurrentunit.ReservationStations "maskwid" parameter, which is
set one per CompUnit.  with the cancellation mask being N bits wide,
N go_die CompUnits may be connected together on the front, one go_die signal
to each cancellation mask bit.