OpenCores
URL https://opencores.org/ocsvn/zipcpu/zipcpu/trunk

Subversion Repositories zipcpu

[/] [zipcpu/] - Rev 56

Rev

Go to most recent revision

Filtering Options

Clear current filter

Rev Log message Author Age Path
56 Here's a bit of work in progress for getting the Zip CPU working on a XuLA2
board. Many changes include: the existence of a cpudefs.v file to control
what "options" are included in the ZipCPU build. This allows build control
to be separated from the project directory (one build for a XuLA2 board,
another for a Basys-3 development board). Other changes have made things
perhaps harder to read, but they get rid of warnings from XST.

A big change was the addition of the (* ram_style="distributed" *) comment
for the register set. This was necessary to keep XST from inferring a block
RAM and breaking the logic that was supposed to take place between a register
read and when it was used.
dgisselq 3089d 23h /zipcpu/
55 A test was added to double check whether carry following right shifts worked.
This was a necessary part of getting two cycle linear feedback shift register
operations working for a memory test on a XuLA2 board. With this, I can now
verify that such feedback registers work for pseudorandom number purposes.
dgisselq 3089d 23h /zipcpu/
54 This builds on the support for backslash character escapes in both single
and multicharacter expressions. Backslash character escapes are now
possible with quotations and backslashes, and the same code to interpret
the escapes is applied to both single and multicharacter sequences.
dgisselq 3089d 23h /zipcpu/
53 Updated the #include/#define directives to work properly for nested includes.
(They were supposed to work properly for nested includes before ... and didn't)
This fixes those bugs.
dgisselq 3089d 23h /zipcpu/
52 Added the capability to "see" character's encoded within a binary file,
by printing the character value(s) of each opcode (if they are printable)
on each line.
dgisselq 3089d 23h /zipcpu/
51 Added the capability to look at binary files and 'see' characters as they
are encoded in memory.
dgisselq 3089d 23h /zipcpu/
50 Dhrystone benchmark updates--added the copyright notice. (Oops!) dgisselq 3099d 15h /zipcpu/
49 Final set of changes finishing the Dhrystone package. Dhrystone, as
implemented by hand in assembly, now works.
dgisselq 3099d 15h /zipcpu/
48 Files added/updated to get Dhrystone benchmark to work. Several fixes
to the CPU in the process, 'cause it wasn't working. Stall-less ALU
ops now work better, to include grabbing the memory result as it comes out
of the memory unit and placing it straight into either ALU or memory unit
for the next instruction.
dgisselq 3099d 15h /zipcpu/
47 Added some new graphics, includes the file for the Zip Bones system. dgisselq 3099d 15h /zipcpu/
46 A series of updates associated with getting Dhrystone to work. Includes
updates to getting multiple files to link/work together within the assembler,
as well as getting quoted quotations to work in the lexer, and better
include file support in the preprocessor.
dgisselq 3099d 15h /zipcpu/
45 Library routines for 32-bit multiply and divide, both signed and unsigned. dgisselq 3099d 15h /zipcpu/
44 ?? dgisselq 3099d 15h /zipcpu/
43 Minor edits to the C++ testbench. dgisselq 3099d 15h /zipcpu/
42 Oops -- forgot to add the stack. dgisselq 3099d 15h /zipcpu/
41 Assembly file for the Dhrystone benchmark added. dgisselq 3099d 15h /zipcpu/
40 Quick update, updates the assembly for the new version of the assembler. dgisselq 3099d 15h /zipcpu/
39 Here's the documentation update to support the pipelined read/writes of
the bus from the CPU, as well as the test file that proved they worked.
dgisselq 3102d 18h /zipcpu/
38 A couple of quick updates:

- The Zip CPU now supports pipelined memory access at one clock per
instruction (assuming all the instructions are in the cache)
- There is now a 'zipbones' module to build a Zip System without peripherals.
Any peripherals would then need to be external to the CPU.
- Some bug fixes.

Documentation changes coming shortly.
dgisselq 3102d 20h /zipcpu/
37 Fixed some minor spelling errors. dgisselq 3111d 11h /zipcpu/
36 *Lots* of changes to increase processing speed and remove pipeline stalls.

Removed the useless flash cache, replacing it with a proper DMA controller.

"make test" in the main directory now runs a test program in Verilator and
reports on the results.
dgisselq 3111d 23h /zipcpu/
35 I updated the system diagram to reflect the new version that has a direct
memory access controller, rather than the (useless) manual cache.
dgisselq 3128d 14h /zipcpu/
34 Bunches of changes, although very little changed with the core itself.

Regarding the core, some bugs were fixed within zipcpu.v (the CPU part of the
core), so that the debugger can change the program counter. The debugger
can now halt the CPU and then view, examine, and modify registers to include
the program counter, although live changes to the CC register have not been
tested.

There was also a bug in the stall handling of the wishbone bus delay line. This
has now been fixed.

Moving outwards to the system, some parameters have been added to zipsystem
to make it more configurable for whatever environment you might wish to place
it within. Other minor clean ups have taken place, mostly to the internal
documentation.

Lots of changes, though, to the assembler. The big one is the implementation
of #define macros, C style. Several buggy macros were in sys.i. These have
been fixed. The Makefile has been adjusted so that the build of test.S, which
depends upon sys.i, is now properly dependent upon sys.i for make purposes.
Further, not only will zpp, the assembler preprocessor, handle #define macros,
it will also recursive #defines. The assembler expression evaluator has also
been updated to properly handle both operator precedence, as well as modulo
arithmetic.

The master system test file, test.S, found in the sw/zasm directory has been
updated to reflect these new capabilities. (I really need to move it to the
bench/asm directory, so you may expect that change sometime later.)
dgisselq 3137d 18h /zipcpu/
33 Finally finished a first draft of the full specification! dgisselq 3140d 17h /zipcpu/
32 Updated the document to match the most recent changes to the CPU. Specifically,
these include the re-instatement of the full SUB command with immediate offset,
and ... others I cannot remember.

The new document also describes what conditions create pipeline stalls,
together with how many cycles each stall condition will create.
dgisselq 3141d 00h /zipcpu/
31 README now comments on the relationship between the debugger and the
test bench. (They came from the same code at one time ...)
dgisselq 3141d 02h /zipcpu/
30 Here's a 20% increase in performance: We've gone from 0.44 clocks per
instruction up to 0.53 clocks per instruction on the test.S testset. The
cost? Oh, only about 300 slices.

Not bad.

The specification document will also soon be updated with a list of
conditions that create stalls, as eliminating stalls was how I managed to get
the performance up like I did.
dgisselq 3141d 02h /zipcpu/
29 Not sure what this file was, but it isn't a part of the project anymore. dgisselq 3141d 10h /zipcpu/
28 I got tired of running the make files across multiple directories, so I
built this makefile to coordinate building across each directory.
dgisselq 3141d 11h /zipcpu/
27 The big change to the test bench code in this directory is the support for
non-interactive operation. The test bench will now run in non-interactive
mode until either the CPU HALT's or executes a BUSY instruction. A 'HALT'
is deemed a test success, whereas a BUSY is deemed a test failure.

A usage() statement now informs the user what commands are available while
running the test bench interactively. (It looks a lot like the debugger looks
like, should you manage to get that up and running.)

The make file now also supports interactive and non-interactive testing via
the 'make itest' and 'make test' targets respectively.
dgisselq 3141d 11h /zipcpu/

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.