1===================================
2cfag12864b LCD Driver Documentation
3===================================
4
5:License:		GPLv2
6:Author & Maintainer:	Miguel Ojeda <ojeda@kernel.org>
7:Date:			2006-10-27
8
9
10
11.. INDEX
12
13	1. DRIVER INFORMATION
14	2. DEVICE INFORMATION
15	3. WIRING
16	4. USERSPACE PROGRAMMING
17
181. Driver Information
19---------------------
20
21This driver supports a cfag12864b LCD.
22
23
242. Device Information
25---------------------
26
27:Manufacturer:	Crystalfontz
28:Device Name:	Crystalfontz 12864b LCD Series
29:Device Code:	cfag12864b
30:Webpage:	http://www.crystalfontz.com
31:Device Webpage: http://www.crystalfontz.com/products/12864b/
32:Type:		LCD (Liquid Crystal Display)
33:Width:		128
34:Height:	64
35:Colors:	2 (B/N)
36:Controller:	ks0108
37:Controllers:	2
38:Pages:		8 each controller
39:Addresses:	64 each page
40:Data size:	1 byte each address
41:Memory size:	2 * 8 * 64 * 1 = 1024 bytes = 1 Kbyte
42
43
443. Wiring
45---------
46
47The cfag12864b LCD Series don't have official wiring.
48
49The common wiring is done to the parallel port as shown::
50
51  Parallel Port                          cfag12864b
52
53    Name Pin#                            Pin# Name
54
55  Strobe ( 1)------------------------------(17) Enable
56  Data 0 ( 2)------------------------------( 4) Data 0
57  Data 1 ( 3)------------------------------( 5) Data 1
58  Data 2 ( 4)------------------------------( 6) Data 2
59  Data 3 ( 5)------------------------------( 7) Data 3
60  Data 4 ( 6)------------------------------( 8) Data 4
61  Data 5 ( 7)------------------------------( 9) Data 5
62  Data 6 ( 8)------------------------------(10) Data 6
63  Data 7 ( 9)------------------------------(11) Data 7
64         (10)                      [+5v]---( 1) Vdd
65         (11)                      [GND]---( 2) Ground
66         (12)                      [+5v]---(14) Reset
67         (13)                      [GND]---(15) Read / Write
68    Line (14)------------------------------(13) Controller Select 1
69         (15)
70    Init (16)------------------------------(12) Controller Select 2
71  Select (17)------------------------------(16) Data / Instruction
72  Ground (18)---[GND]              [+5v]---(19) LED +
73  Ground (19)---[GND]
74  Ground (20)---[GND]              E    A             Values:
75  Ground (21)---[GND]       [GND]---[P1]---(18) Vee    - R = Resistor = 22 ohm
76  Ground (22)---[GND]                |                 - P1 = Preset = 10 Kohm
77  Ground (23)---[GND]       ----   S ------( 3) V0     - P2 = Preset = 1 Kohm
78  Ground (24)---[GND]       |  |
79  Ground (25)---[GND] [GND]---[P2]---[R]---(20) LED -
80
81
824. Userspace Programming
83------------------------
84
85The cfag12864bfb describes a framebuffer device (/dev/fbX).
86
87It has a size of 1024 bytes = 1 Kbyte.
88Each bit represents one pixel. If the bit is high, the pixel will
89turn on. If the pixel is low, the pixel will turn off.
90
91You can use the framebuffer as a file: fopen, fwrite, fclose...
92Although the LCD won't get updated until the next refresh time arrives.
93
94Also, you can mmap the framebuffer: open & mmap, munmap & close...
95which is the best option for most uses.
96
97Check samples/auxdisplay/cfag12864b-example.c
98for a real working userspace complete program with usage examples.
99