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Rev Log message Author Age Path
20 Revert "Corrected unconnected enable line" in memory_ifc module. Fixes erroneous extra delay of nIORQ signal on INT ACK. gdevic 2137d 02h /a-z80/trunk/
19 Some documentation updates gdevic 2148d 06h /a-z80/trunk/
18 Correctly latch IO RW wait request

Fixed bug: Issuing nWAIT during IO RW was ignored (IORQ, not M1)
Taping into a correct point of IORQ generator sequence train gives
an additional signal to be OR-ed when composing a generic latch_wait

Corrected unconnected enable line
gdevic 2425d 20h /a-z80/trunk/
17 z80: Release 5 gdevic 2833d 20h /a-z80/trunk/
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 2866d 11h /a-z80/trunk/
15 zxspectrum: Fix few Quartus warnings gdevic 2866d 22h /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 2866d 23h /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 2867d 20h /a-z80/trunk/
12 Explicitly set python to execute within a batch file gdevic 2880d 12h /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 3092d 22h /a-z80/trunk/
10 zxspectrum: Various improvements

- Fixed keyboard bug (by Bogdan S.)
- Minor comment changes
- Renamed reset to nreset
gdevic 3138d 12h /a-z80/trunk/
9 Updated documentation gdevic 3139d 06h /a-z80/trunk/
8 z80: Release 4 gdevic 3139d 08h /a-z80/trunk/
7 z80: Fixing repeating INIR/OTIR class of instructions gdevic 3203d 12h /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 3553d 23h /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 3583d 12h /a-z80/trunk/
3 - New directory structure
- Added documentation files (and PDF versions)
- Fixed tests
gdevic 3589d 13h /a-z80/trunk/
1 The project and the structure was created root 3595d 19h /a-z80/trunk/

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