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[/] [zipcpu/] [trunk/] [rtl/] [core/] - Rev 209

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Rev Log message Author Age Path
129 Bug fix. Fixes some ugly race conditions that would cause code from the wrong
address to be executed.		 dgisselq 3342d 00h /zipcpu/trunk/rtl/core/
118 Fixes two bugs: 1) in the early branching code within the instruction decoder.
This prevented the early branching from working when built with Xilinx's tools,
while the code worked with Verilator. 2) The CPU was not working with the
traditional cache and early branching disabled. These two bugs masked each
other. The replacement code is simpler.		 dgisselq 3361d 01h /zipcpu/trunk/rtl/core/
105 Fixed some nasty early branching bugs. Adjusted the Makefile to declare that
cpudefs.h was automatically generated from cpudefs.v, and made sure that
zipbones included the cpudefs.v so it could get the DEBUG_SCOPE define.
In addition, the test.S was updated to test long jumps, the early branching
bug we found, and all three early branching instructions: ADD #x,PC, LOC(PC),PC,
and LDI #x,PC.		 dgisselq 3385d 09h /zipcpu/trunk/rtl/core/
91 Minor updates. dgisselq 3426d 02h /zipcpu/trunk/rtl/core/
90 Removed MOV x(PC),PC from the list of possible early branching instructions.
ADD X,PC and LDI X,PC are now the only recognized early branching instructions.
This was done to spare logic, although I don't think I spared more than a
LUT or two.		 dgisselq 3426d 02h /zipcpu/trunk/rtl/core/
88 Eliminated some warnings. The div fixes were to simplify the logic, even though
the result is less readable ...		 dgisselq 3450d 02h /zipcpu/trunk/rtl/core/
83 Added a flag to indicate whether an exception took place on the first
or second half of a VLIW instruction--will be zero in non-VLIW mode,
equivalent to the second half of the instruction having caused the
exception. (Expect these flags to be reordered some time in the future into
a less haphazard ordering ...)

Vastly simplified the pipeline logic, primarily for op_stall, but also touched
opA and opB. (Trying to fit within timing on Spartan 6 ...)

Changed division instruction to include a reset on clear_pipeline, to make
certain [BC $addr; DIV Rx,Ry ] works regardless of whether the condition is
true.		 dgisselq 3452d 01h /zipcpu/trunk/rtl/core/
82 Found and (I hope) fixed a nasty bug that would send the prefetch into an
endless loop whenever you jumped to an instruction at the last location
in an unloaded cache line.		 dgisselq 3452d 01h /zipcpu/trunk/rtl/core/
81 Trying to clean up ISE generated warnings. dgisselq 3452d 01h /zipcpu/trunk/rtl/core/
80 Bug fix: declared the (combined) multiply to be signed again. Also
changed the name of the generate'd for block, to keep ISE from complaining.		 dgisselq 3452d 01h /zipcpu/trunk/rtl/core/

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