99 lines
3.1 KiB
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99 lines
3.1 KiB
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cfag12864b LCD Driver Documentation
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===================================
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:License: GPLv2
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:Author & Maintainer: Miguel Ojeda <ojeda@kernel.org>
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:Date: 2006-10-27
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.. INDEX
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1. DRIVER INFORMATION
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2. DEVICE INFORMATION
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3. WIRING
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4. USERSPACE PROGRAMMING
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1. Driver Information
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---------------------
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This driver supports a cfag12864b LCD.
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2. Device Information
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---------------------
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:Manufacturer: Crystalfontz
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:Device Name: Crystalfontz 12864b LCD Series
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:Device Code: cfag12864b
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:Webpage: http://www.crystalfontz.com
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:Device Webpage: http://www.crystalfontz.com/products/12864b/
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:Type: LCD (Liquid Crystal Display)
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:Width: 128
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:Height: 64
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:Colors: 2 (B/N)
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:Controller: ks0108
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:Controllers: 2
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:Pages: 8 each controller
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:Addresses: 64 each page
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:Data size: 1 byte each address
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:Memory size: 2 * 8 * 64 * 1 = 1024 bytes = 1 Kbyte
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3. Wiring
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---------
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The cfag12864b LCD Series don't have official wiring.
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The common wiring is done to the parallel port as shown::
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Parallel Port cfag12864b
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Name Pin# Pin# Name
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Strobe ( 1)------------------------------(17) Enable
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Data 0 ( 2)------------------------------( 4) Data 0
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Data 1 ( 3)------------------------------( 5) Data 1
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Data 2 ( 4)------------------------------( 6) Data 2
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Data 3 ( 5)------------------------------( 7) Data 3
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Data 4 ( 6)------------------------------( 8) Data 4
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Data 5 ( 7)------------------------------( 9) Data 5
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Data 6 ( 8)------------------------------(10) Data 6
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Data 7 ( 9)------------------------------(11) Data 7
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(10) [+5v]---( 1) Vdd
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(11) [GND]---( 2) Ground
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(12) [+5v]---(14) Reset
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(13) [GND]---(15) Read / Write
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Line (14)------------------------------(13) Controller Select 1
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(15)
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Init (16)------------------------------(12) Controller Select 2
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Select (17)------------------------------(16) Data / Instruction
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Ground (18)---[GND] [+5v]---(19) LED +
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Ground (19)---[GND]
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Ground (20)---[GND] E A Values:
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Ground (21)---[GND] [GND]---[P1]---(18) Vee - R = Resistor = 22 ohm
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Ground (22)---[GND] | - P1 = Preset = 10 Kohm
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Ground (23)---[GND] ---- S ------( 3) V0 - P2 = Preset = 1 Kohm
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Ground (24)---[GND] | |
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Ground (25)---[GND] [GND]---[P2]---[R]---(20) LED -
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4. Userspace Programming
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------------------------
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The cfag12864bfb describes a framebuffer device (/dev/fbX).
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It has a size of 1024 bytes = 1 Kbyte.
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Each bit represents one pixel. If the bit is high, the pixel will
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turn on. If the pixel is low, the pixel will turn off.
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You can use the framebuffer as a file: fopen, fwrite, fclose...
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Although the LCD won't get updated until the next refresh time arrives.
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Also, you can mmap the framebuffer: open & mmap, munmap & close...
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which is the best option for most uses.
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Check samples/auxdisplay/cfag12864b-example.c
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for a real working userspace complete program with usage examples.
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