| Rev |
Log message |
Author |
Age |
Path |
| 79 |
Adjusted the opcodes for NOOP, BREAK, and LOCK. |
dgisselq |
3876d 17h |
/zipcpu/ |
| 78 |
Found/corrected annoying bug in floating point documentation of the opcode
table. |
dgisselq |
3876d 17h |
/zipcpu/ |
| 77 |
First check-in: the test bench for the divide instruction. |
dgisselq |
3877d 16h |
/zipcpu/ |
| 76 |
The biggest change here was to zippy_tb, to make it more similar to the debugger
and to make it work with VLIW-type instructions. |
dgisselq |
3877d 16h |
/zipcpu/ |
| 75 |
Modified for VLIW instructions. |
dgisselq |
3877d 16h |
/zipcpu/ |
| 74 |
Added a bunch of debugging code to the Dhrystone benchmark assembly file, as
well as two new testing assembly files. |
dgisselq |
3877d 16h |
/zipcpu/ |
| 73 |
Documentations updates. |
dgisselq |
3877d 17h |
/zipcpu/ |
| 72 |
Some updated graphics, now containing images of the CPU that include the
divide and (currently non-existant) floating point unit. |
dgisselq |
3877d 17h |
/zipcpu/ |
| 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 |
3877d 17h |
/zipcpu/ |
| 70 |
Updated the assembler support files, zopcodes in particular, to handle
the disassembly of the new very long instruction word codes. |
dgisselq |
3877d 17h |
/zipcpu/ |
| 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 |
3883d 21h |
/zipcpu/ |
| 68 |
Updated specification, includes well illustrated pipeline discussion. |
dgisselq |
3918d 21h |
/zipcpu/ |
| 67 |
Includes timing diagrams in support of a very descriptive specification section. |
dgisselq |
3918d 22h |
/zipcpu/ |
| 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 |
3944d 21h |
/zipcpu/ |
| 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 |
3944d 21h |
/zipcpu/ |
| 64 |
Shuffled some comments into here from elsewhere. |
dgisselq |
3944d 21h |
/zipcpu/ |
| 63 |
Simplified bus interactions, and added support for detecting illegal
instructions (i.e. bus errors) in the pipefetch routine. |
dgisselq |
3944d 21h |
/zipcpu/ |
| 62 |
Simplified the subtraction logic, so the carry bit no longer depends on
a separate 32-bit operation but becomes part of the subtract operation. |
dgisselq |
3944d 21h |
/zipcpu/ |
| 61 |
Simplified the bus delay logic. Depends upon the stall line being irrelevant
outside of a bus cycle. |
dgisselq |
3944d 21h |
/zipcpu/ |
| 60 |
Fixed assembler processing of jump instructions, so that the new fast
return instruction can be used. The test file was modified to test
pipelined value passing within the CPU. That's where the value gets
(re)used before being stored back in the register file. As of this release,
all tests work. |
dgisselq |
3944d 21h |
/zipcpu/ |
