-
Notifications
You must be signed in to change notification settings - Fork 3
/
VGA_512x384_Bitmap.spin
224 lines (173 loc) · 21.5 KB
/
VGA_512x384_Bitmap.spin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
''********************************************
''* VGA 512x384 2-Color Bitmap Driver v1.0 *
''* Author: Chip Gracey *
''* Copyright (c) 2006 Parallax, Inc. *
''* See end of file for terms of use. *
''********************************************
''
'' This object generates a 512x384 pixel bitmap, signaled as 1024x768 VGA.
'' Each pixel is one bit, so the entire bitmap requires 512 x 384 / 32 longs,
'' or 6,144 longs (24KB). Color words comprised of two byte fields provide
'' unique colors for every 32x32 pixel group. These color words require 512/32
'' * 384/32 words, or 192 words. Pixel memory and color memory are arranged
'' left-to-right then top-to-bottom.
''
'' A sync indicator signals each time the screen is drawn (you may ignore).
''
'' You must provide buffers for the colors, pixels, and sync. Once started,
'' all interfacing is done via memory. To this object, all buffers are read-
'' only, with the exception of the sync indicator which gets written with a
'' non-0 value. You may freely write all buffers to affect screen appearance.
''
CON
' 512x384 settings - signals as 1024 x 768 @ 67Hz
hp = 512 'horizontal pixels
vp = 384 'vertical pixels
hf = 8 'horizontal front porch pixels
hs = 48 'horizontal sync pixels
hb = 88 'horizontal back porch pixels
vf = 1 'vertical front porch lines
vs = 3 'vertical sync lines
vb = 28 'vertical back porch lines
hn = 1 'horizontal normal sync state (0|1)
vn = 1 'vertical normal sync state (0|1)
pr = 35 'pixel rate in MHz at 80MHz system clock (5MHz granularity)
' Tiles
xtiles = hp / 32
ytiles = vp / 32
' H/V inactive states
hv_inactive = (hn << 1 + vn) * $0101
VAR long cog
PUB start(BasePin, ColorPtr, PixelPtr, SyncPtr) : okay | i, j
'' Start VGA driver - starts a COG
'' returns false if no COG available
''
'' BasePin = VGA starting pin (0, 8, 16, 24, etc.)
''
'' ColorPtr = Pointer to 192 words which define the "0" and "1" colors for
'' each 32x32 pixel group. The lower byte of each word contains
'' the "0" bit RGB data while the upper byte of each word contains
'' the "1" bit RGB data for the associated group. The RGB
'' data in each byte is arranged as %RRGGBB00 (4 levels each).
''
'' color word example: %%0020_3300 = "0" = gold, "1" = blue
''
'' PixelPtr = Pointer to 6,144 longs containing pixels that make up the 512 x
'' 384 pixel bitmap. Longs' LSBs appear left on the screen, while
'' MSBs appear right. The longs are arranged in sequence from left-
'' to-right, then top-to-bottom.
''
'' SyncPtr = Pointer to long which gets written with non-0 upon each screen
'' refresh. May be used to time writes/scrolls, so that chopiness
'' can be avoided. You must clear it each time if you want to see
'' it re-trigger.
'if driver is already running, stop it
stop
'implant pin settings and pointers, then launch COG
reg_vcfg := $200000FF + (BasePin & %111000) << 6
i := $FF << (BasePin & %011000)
j := BasePin & %100000 == 0
reg_dira := i & j
reg_dirb := i & !j
longmove(@color_base, @ColorPtr, 2)
if (cog := cognew(@init, SyncPtr) + 1)
return true
PUB stop | i
'' Stop VGA driver - frees a COG
if cog
cogstop(cog~ - 1)
DAT
'***********************************************
'* Assembly language VGA 2-color bitmap driver *
'***********************************************
org 'set origin to $000 for start of program
' Initialization code - init I/O
init mov dira,reg_dira 'set pin directions
mov dirb,reg_dirb
movi ctra,#%00001_101 'enable PLL in ctra (VCO runs at 4x)
movi frqa,#(pr / 5) << 3 'set pixel rate
mov vcfg,reg_vcfg 'set video configuration
' Main loop, display field and do invisible sync lines
field mov color_ptr,color_base 'reset color pointer
mov pixel_ptr,pixel_base 'reset pixel pointer
mov y,#ytiles 'set y tiles
:ytile mov yl,#32 'set y lines per tile
:yline mov yx,#2 'set y expansion
:yexpand mov x,#xtiles 'set x tiles
mov vscl,vscl_pixel 'set pixel vscl
:xtile rdword color,color_ptr 'get color word
and color,colormask 'clear h/v bits
or color,hv 'set h/v inactive states
rdlong pixel,pixel_ptr 'get pixel long
waitvid color,pixel 'pass colors and pixels to video
add color_ptr,#2 'point to next color word
add pixel_ptr,#4 'point to next pixel long
djnz x,#:xtile 'another x tile?
sub color_ptr,#xtiles * 2 'repoint to first colors in same line
sub pixel_ptr,#xtiles * 4 'repoint to first pixels in same line
mov x,#1 'do horizontal sync
call #hsync
djnz yx,#:yexpand 'y expand?
add pixel_ptr,#xtiles * 4 'point to first pixels in next line
djnz yl,#:yline 'another y line in same tile?
add color_ptr,#xtiles * 2 'point to first colors in next tile
djnz y,#:ytile 'another y tile?
wrlong colormask,par 'visible done, write non-0 to sync
mov x,#vf 'do vertical front porch lines
call #blank
mov x,#vs 'do vertical sync lines
call #vsync
mov x,#vb 'do vertical back porch lines
call #vsync
jmp #field 'field done, loop
' Subroutine - do blank lines
vsync xor hvsync,#$101 'flip vertical sync bits
blank mov vscl,hvis 'do blank pixels
waitvid hvsync,#0
hsync mov vscl,#hf 'do horizontal front porch pixels
waitvid hvsync,#0
mov vscl,#hs 'do horizontal sync pixels
waitvid hvsync,#1
mov vscl,#hb 'do horizontal back porch pixels
waitvid hvsync,#0
djnz x,#blank 'another line?
hsync_ret
blank_ret
vsync_ret ret
' Data
reg_dira long 0 'set at runtime
reg_dirb long 0 'set at runtime
reg_vcfg long 0 'set at runtime
color_base long 0 'set at runtime (2 contiguous longs)
pixel_base long 0 'set at runtime
vscl_pixel long 1 << 12 + 32 '1 pixel per clock and 32 pixels per set
colormask long $FCFC 'mask to isolate R,G,B bits from H,V
hvis long hp 'visible pixels per scan line
hv long hv_inactive '-H,-V states
hvsync long hv_inactive ^ $200 '+/-H,-V states
' Uninitialized data
color_ptr res 1
pixel_ptr res 1
color res 1
pixel res 1
x res 1
y res 1
yl res 1
yx res 1
{{
┌──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ TERMS OF USE: MIT License │
├──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation │
│files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, │
│modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software│
│is furnished to do so, subject to the following conditions: │
│ │
│The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.│
│ │
│THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE │
│WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR │
│COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, │
│ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. │
└──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
}}