| Rev |
Log message |
Author |
Age |
Path |
| 176 |
Switched from distributed to block RAM, and adjusted the logic to help
timing closure. The resulting core will build in designs up to 200MHz in
speed. |
dgisselq |
3001d 00h |
/zipcpu/trunk/rtl/ |
| 175 |
Fixed the carry bit for logical shifts: it is the last bit shifted out of the
register. 0x80000000>>32 yields a 0 with carry set. Anything logically
shifted by a number greater than thirty two clears carry and register. |
dgisselq |
3001d 00h |
/zipcpu/trunk/rtl/ |
| 174 |
Simplified the divide to improve timing performance. |
dgisselq |
3001d 00h |
/zipcpu/trunk/rtl/ |
| 160 |
Logic updates, and bug fix corrections to bring this in line with the current
XuLA2-LX25 SoC version. (i.e., the XuLA version was debugged and improved,
this update pushes those improvements to the mainline.) |
dgisselq |
3093d 20h |
/zipcpu/trunk/rtl/ |
| 157 |
Added the divide unit to the list of ZipCPU dependencies. |
dgisselq |
3093d 20h |
/zipcpu/trunk/rtl/ |
| 145 |
This fixes the pipelined memory problem that was introduced a while back to
fix ... pipelined memory conflicts. This appears to maintain the success
of the fix, while recovering the pipeline memory performance that was had
before. |
dgisselq |
3126d 19h |
/zipcpu/trunk/rtl/ |
| 144 |
Makes the auto-reload capability a configuration option, and fills out the
reset so that it is properly implemented. |
dgisselq |
3126d 19h |
/zipcpu/trunk/rtl/ |
| 140 |
Minor changes, but fixes build of zippy_tb.cpp. |
dgisselq |
3130d 08h |
/zipcpu/trunk/rtl/ |
| 138 |
This updates the CPU multiply instruction into a set of three instructions.
MPY is a 32x32-bit multiply instruction, returning the low 32-bit result,
MPYUHI returns the upper 32-bits assuming the result was unsigned and MPYSHI
returns the upper 32-bits assuming the result was signed. |
dgisselq |
3133d 06h |
/zipcpu/trunk/rtl/ |
| 133 |
Changes preceding an instruction set update, which will change the multiply
operation from a 16x16 bit multiply to three types of 32x32-bit multiplies. |
dgisselq |
3147d 20h |
/zipcpu/trunk/rtl/ |
| 132 |
Lots of minor bug fixes. |
dgisselq |
3147d 20h |
/zipcpu/trunk/rtl/ |
| 131 |
Fixed a variable use before declaration error. |
dgisselq |
3147d 20h |
/zipcpu/trunk/rtl/ |
| 130 |
Simplified the lock logic, and removed it when pipelining was not defined. This
also means the file is now dependent upon cpudefs.v. In another change, brev
was modified so as not to update the flags. This makes it useable with GCC
as a potential move or load immediate instruction. |
dgisselq |
3147d 20h |
/zipcpu/trunk/rtl/ |
| 129 |
Bug fix. Fixes some ugly race conditions that would cause code from the wrong
address to be executed. |
dgisselq |
3147d 20h |
/zipcpu/trunk/rtl/ |
| 128 |
Cleaned up some comments. |
dgisselq |
3147d 20h |
/zipcpu/trunk/rtl/ |
| 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 |
3166d 21h |
/zipcpu/trunk/rtl/ |
| 115 |
A bug fix, applies to when there are more than 9 interrupt lines into the CPU. |
dgisselq |
3167d 05h |
/zipcpu/trunk/rtl/ |
| 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 |
3191d 05h |
/zipcpu/trunk/rtl/ |
| 91 |
Minor updates. |
dgisselq |
3231d 22h |
/zipcpu/trunk/rtl/ |
| 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 |
3231d 22h |
/zipcpu/trunk/rtl/ |
| 88 |
Eliminated some warnings. The div fixes were to simplify the logic, even though
the result is less readable ... |
dgisselq |
3255d 22h |
/zipcpu/trunk/rtl/ |
| 84 |
Minor updates. |
dgisselq |
3257d 21h |
/zipcpu/trunk/rtl/ |
| 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 |
3257d 21h |
/zipcpu/trunk/rtl/ |
| 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 |
3257d 21h |
/zipcpu/trunk/rtl/ |
| 81 |
Trying to clean up ISE generated warnings. |
dgisselq |
3257d 21h |
/zipcpu/trunk/rtl/ |
| 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 |
3257d 21h |
/zipcpu/trunk/rtl/ |
| 71 |
This contains a bunch of bug fixes. (A lot ...) For example, the pipeline
stall code has also seriously changed, to fixed the pipeline memory load/op
stage conflict, while maintaining no-stall operation for operands that don't
need an offset. This had a cascading effect, however, so that the multiply
could no longer complete in a single cycle. Therefore, the timing on the
multiplies was slowed down to two cycles from a single cycle. (It's the
only two-cycle ALU operation ...) The illegal instruction code has also been
fixed, so that illegal instructions no longer stalls the prefetch bus. |
dgisselq |
3263d 00h |
/zipcpu/trunk/rtl/ |
| 69 |
This implements the "new Instruction Set" architecture for the Zip CPU. It's
a massive change set, that touches just about everything but probably not
enough of everything. Please see the spec.pdf for a description of this
new architecture. |
dgisselq |
3269d 04h |
/zipcpu/trunk/rtl/ |
| 66 |
Adjusted the support for the DEBUG_SCOPE within these so that it can be
compiled in, or not, based upon an external build configuration file: cpudefs.v.
That allows me to make that file project specific, while the rest of the CPU
is shared among all projects. |
dgisselq |
3330d 04h |
/zipcpu/trunk/rtl/ |
| 65 |
Lots of logic simplifications to the core, in addition to better support for
illegal instruction detection and bus error detection. The biggest change
had to deal with pushing the debug write interface into the ALU write
processing path. This simplifies the logic of adjusting the PC and CC
registers primarily, but also any writes to other registers. It also delays
these register writes by a clock, but since the debug interface is already
ridiculously slow I doubt that matters any. |
dgisselq |
3330d 04h |
/zipcpu/trunk/rtl/ |
