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updated various code lines due to "fixed predecrement CPU bug"
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@sy2002
sy2002 committed Feb 13, 2016
1 parent 8e368ed commit ad89665
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Showing 7 changed files with 46 additions and 39 deletions.
57 changes: 33 additions & 24 deletions TODO.txt
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@@ -1,28 +1,37 @@
FINALIZING THE CURRENT "STREAK" of FPGA + Q-TRIS:

* Q-TRIS V1.0: Implement winning the game (>= 1.000 lines), take care that
upleveling does not lead to undefined memory locations (table). Optimize
some code parts (at least those resulting from the CPU fix).

* Q-TRIS and/or Monitor: Stand alone auto-starting Q-TRIS bitstream. Do it in
the most simple form, which is: make it an .org 0x0000 startable executable,
move the variables that need to be in RAM via other .org commands. (That
means, we need a simple multiplication command outside the monitor.)

* Test Q-TRIS thoroughly again by playing a ~250+ lines session.

* Make a V1.21 release of the hardware and the whole package (and include
the Q-TRIS as a stand alone released bitstream)

HARDWARE:

* Fix CPU BUG: Pre-decrement of the destination operand does not work,
if the source operand is used directly. But it works, if the source
operand is used indirectly. Example:
this works: MOVE @R2, @--R0
this does not work: MOVE R2, @--R0
The bug will be presumably fixed, by changing
and Opcode /= opcMOVE
in vhdl/qnice_cpu.vhd line 401 to
and (Opcode /= opcMOVE or Dst_Mode = amIndirPreDec)
and therefore making it very similar to line 455: The speed optimization
must be disabled in case of pre-decrement.
As soon as this is fixed, the fix can be e.g. tested by changing the two
spots marked with "@TODO" in test_programs/decimal.asm. As soon as
everything works, the code in this test program and also in demos/q-tris.asm
needs to be cleaned up accordingly.

* remove ROM and replace by prefilled RAM
* Remove ROM and replace by prefilled RAM

* Memory management unit (more than 64kWords of RAM/ROM, pages, etc.)

* Interrupt system

* Debugging mechanisms (e.g. single-step mode in hardware)

* Fix tristate problem that slows down CPU by ~50%

* Improve design to support 100 MHz

* keyboard: remove hardcoded hardcoded 18000
* Keyboard: remove hardcoded hardcoded 18000

* Refactor scancode conversion to be more table/ROM like and less
like a huge array of multiplexers

* Add a timer with 0,1us Resolution (10 MHz frequency), so that
we can measure performance (e.g. against the emulator)
Expand All @@ -31,20 +40,20 @@ HARDWARE:

* Refactor TIL and TIL Mask to support 8 digits / 32 bits

* Refactor scancode conversion to be more table/ROM like and less
like a huge array of multiplexers

* Refactor Video RAM: avoid inferring two RAMs for video RAM

* single-step-mode in hardware incl. address/data display on 7-segs
* VGA being able to report the vertical retrace for flicker-free graphics,
e.g. for being able to enhance Q-TRIS to work double-buffered and to
switch buffers during retrace. And/or for having a good general sync.
mechanism. To "report" via register and/or interrupt.

MONITOR and/or STANDARD LIBs:

* Backspace and CTRL-U support in IO$GETS

* Basic mathematical routines * (exists), / (from decimal.asm), % (ditto)
* Basic mathematical routines * (exists), / (from decimal.asm?), % (ditto?)

* Decimal converter (from decimal.asm)
* Decimal converter (from decimal.asm?)

* 32 bit arithmetic

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14 changes: 7 additions & 7 deletions demos/q-tris.asm
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Expand Up @@ -149,7 +149,7 @@ CAH_X .EQU 41
CAH_Y .EQU 8
CAH_W .EQU 40
CAH_H .EQU 10
CRE_A_HELP .ASCII_W "Q-TRIS V0.9 by sy2002 in January 2016 "
CRE_A_HELP .ASCII_W "Q-TRIS V0.9 by sy2002 in February 2016 "
.ASCII_W " "
.ASCII_W "How to play: "
.ASCII_W " "
Expand Down Expand Up @@ -419,11 +419,11 @@ HANDLE_STATS INCRB
; the level is multipled to account for the higher difficulty
; in higher levels
_H_STATS_SCORE MOVE R8, R9
SYSCALL(mult, 1)
SYSCALL(mult, 1) ; @TODO: replace SYSCALLs
MOVE R10, R8
MOVE Level, R9
MOVE @R9, R9
SYSCALL(mult, 1)
SYSCALL(mult, 1) ; @TODO: replace SYSCALLs
MOVE Score, R0
ADD R10, @R0

Expand Down Expand Up @@ -1761,6 +1761,8 @@ PAINT_DIGIT INCRB

INCRB

; @TODO: replace SYSCALLs, so that Q-Tris can run as
; stand alone "app" independendly from the monitor
MOVE DIGITS_WPD, R9 ; calculate offset for digit
SYSCALL(mult, 1) ; pattern: R8 x DIGITS_WPD

Expand Down Expand Up @@ -1867,15 +1869,13 @@ MAKE_DECIMAL INCRB

_MD_LOOP MOVE R4, R9 ; divide by 10
RSUB DIV_AND_MODULO, 1 ; R8 = "shrinked" dividend
SUB 1, R0 ; @TODO: PREDECREMENT CPU BUG!
MOVE R9, @R0 ; extract current digit place
MOVE R9, @--R0 ; extract current digit place
CMP R5, R8 ; done?
RBRA _MD_LOOP, !Z ; no: next iteration

_MD_LEADING_0 CMP R7, R0 ; enough leading "0" there?
RBRA _MD_RET, Z ; yes: return
SUB 1, R0 ; @TODO: PREDECREMENT CPU BUG!
MOVE 0, @R0 ; no: add a "0" digit
MOVE 0, @--R0 ; no: add a "0" digit
RBRA _MD_LEADING_0, 1

_MD_RET MOVE R6, R8 ; restore R8 & R9
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Binary file modified dist_kit/env1.bit
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2 changes: 1 addition & 1 deletion pore/boot_message.asm
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Expand Up @@ -2,4 +2,4 @@ PORE$NEWLINE .ASCII_W "\n"

; PORE$RESETMSG .ASCII_W "QNICE-FPGA [WIP] [only 16 reg-banks!] by sy2002 in January 2016 (GIT #"

PORE$RESETMSG .ASCII_W "QNICE-FPGA Version 1.2 by sy2002 in January 2016 (GIT COMMIT #d52cb2e)\n"
PORE$RESETMSG .ASCII_W "QNICE-FPGA Version 1.21 by sy2002 in February 2016 (GIT COMMIT #8e368ed)\n"
2 changes: 1 addition & 1 deletion pore/boot_message.txt
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Expand Up @@ -2,4 +2,4 @@ PORE$NEWLINE .ASCII_W "\n"

; PORE$RESETMSG .ASCII_W "QNICE-FPGA [WIP] [only 16 reg-banks!] by sy2002 in January 2016 (GIT #"

PORE$RESETMSG .ASCII_W "QNICE-FPGA Version 1.2 by sy2002 in January 2016 (GIT COMMIT #
PORE$RESETMSG .ASCII_W "QNICE-FPGA Version 1.21 by sy2002 in February 2016 (GIT COMMIT #
6 changes: 2 additions & 4 deletions test_programs/decimal.asm
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Expand Up @@ -83,15 +83,13 @@ MAKE_DECIMAL INCRB

_MD_LOOP MOVE R4, R9 ; divide by 10
RSUB DIV_AND_MODULO, 1 ; R8 = "shrinked" dividend
SUB 1, R0 ; @TODO: PREDECREMENT CPU BUG!
MOVE R9, @R0 ; extract current digit place
MOVE R9, @--R0 ; extract current digit place
CMP R5, R8 ; done?
RBRA _MD_LOOP, !Z ; no: next iteration

_MD_LEADING_0 CMP R7, R0 ; enough leading "0" there?
RBRA _MD_RET, Z ; yes: return
SUB 1, R0 ; @TODO: PREDECREMENT CPU BUG!
MOVE 0, @R0 ; no: add a "0" digit
MOVE 0, @--R0 ; no: add a "0" digit
RBRA _MD_LEADING_0, 1

_MD_RET MOVE R6, R8 ; restore R8 & R9
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4 changes: 2 additions & 2 deletions vhdl/env1_globals.vhd
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Expand Up @@ -11,11 +11,11 @@ package env1_globals is

-- file name and file size (in lines) of the file that is converted to the ROM located at 0x0000
constant ROM_FILE : string := "../monitor/monitor.rom";
constant ROM_SIZE : natural := 2838;
constant ROM_SIZE : natural := 2840;

-- file name of file and file size (in lines) of the file containing the Power On & Reset Execution (PORE) ROM
constant PORE_ROM_FILE : string := "../pore/pore.rom";
constant PORE_ROM_SIZE : natural := 455;
constant PORE_ROM_SIZE : natural := 457;

-- size of lower register bank: should be 256
-- set to 16 during development for faster synthesis, routing, etc.
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