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[/] [a-z80/] [trunk/] - Rev 16

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16 Simplify by adding nhold_clk_wait

Inverted version is used to feel AND gates to enable
Keep hold_clk_wait used only in the sequencer
gdevic 2856d 08h /a-z80/trunk/
15 zxspectrum: Fix few Quartus warnings gdevic 2856d 19h /a-z80/trunk/
14 Add hold_clk_wait to ALU CFL latch

This correctly delays latching the C-Flag for CCF instruction when
nWAIT was asserted at that instruction's M1/T2 cycle

UART: fixed two synthesis warnings
gdevic 2856d 20h /a-z80/trunk/
13 Full support for nWAIT during M1 and memory cycles
This set of changes fixes issues with nWAIT signal
Updated reg control, resets, ir modules to handle delay
This correctly delays clearing of IR if the nWAIT was asserted at
the very first M1 cycle
Simplify decode_state to use discrete write enable for CB/ED flags
Gate CB/ED write with hold_clk_wait to enable nWAIT delay
genfuse add code to test nWAIT insertion at M1
Add host wait state circuitry from Zilog manual (wait_state.*)
Add wait test code to basic fpga/modelsim models
Select from 3 options to test wait states:
- no wait state inserted (nWAIT=1)
- insert a wait state to every M1 cycle
- insert a wait state to each memory access cycle
zxspectrum: Add custom NMI handler and a function to enter game pokes after pressing the NMI button
zxspectrum: Corrected bits 7,5 when reading ULA port 254
zxspectrum: Fix the shift key repeat bug
When using additional keys (<,>,?,...) and shift was released before
a symbol, it would repeat. This change fixes that by correctly resetting
keyboard mask state bitfields.
Added new data pins module for Lattice toolset
It has been reported that "data_pins.v" does not compile on Lattice
toolset and this variation of the code has been proposed and verified
by a user.
Fixed M1 during reset
Memory_ifc module set M1 to inactive (high) during nRESET
Exported wait_m1 signal from that module as a testpoint
gdevic 2857d 16h /a-z80/trunk/
12 Explicitly set python to execute within a batch file gdevic 2870d 09h /a-z80/trunk/
11 zxspectrum improvements:

- Added ZX Spectrum ROM mods as described in the blog:
http://www.baltazarstudios.com/zx-spectrum-rom-mods
This mod allows NMI interrupt to break into a special
handler code inside the ROM image and let the user
type a POKE address (5 decimal digits) + value (3
decimal digits) to modify a memory location
- Changed default joystick pins to Atari style joystick
as described in the blog
- Added a timing constraints file
gdevic 3082d 18h /a-z80/trunk/
10 zxspectrum: Various improvements

- Fixed keyboard bug (by Bogdan S.)
- Minor comment changes
- Renamed reset to nreset
gdevic 3128d 09h /a-z80/trunk/
9 Updated documentation gdevic 3129d 02h /a-z80/trunk/
8 z80: Release 4 gdevic 3129d 05h /a-z80/trunk/
7 z80: Fixing repeating INIR/OTIR class of instructions gdevic 3193d 09h /a-z80/trunk/
6 Added deployment folder with all files needed to use the CPU
Changed ZX Spectrum project to use deployment files as example
Changed extension for Verilog include files from *.i to *.vh
Updated documentation; added section on file generators
Minor corrections and fixes to various files
gdevic 3543d 19h /a-z80/trunk/
5 zxspectrum: Various improvements

- Added "Turbo" speed mode switch (SW2)
- Turbo speed is (3.5 MHz x 2 = 7.0 MHz)
- LEDG5 lits when a key is being pressed
- LEDG6 blinks when a speaker/line-in is being toggled

Misc:
- Fixed a false clock for ula:beep
- Fixed unused Kempston input warning
- Updated documentation to 1.1
gdevic 3573d 08h /a-z80/trunk/
3 - New directory structure
- Added documentation files (and PDF versions)
- Fixed tests
gdevic 3579d 09h /a-z80/trunk/
1 The project and the structure was created root 3585d 16h /a-z80/trunk/

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