+++ /dev/null
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-Hitachi HD44780 display controller, 4-bit mode, initialization sequence
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-
-This capture contains the initialization sequence of an Hitachi HD44780
-display controller which is very popular for 2x16, 4x20, and similar
-character oriented display modules.
-
-The specific hardware setup that got recorded uses 4-bit mode, which
-means that data gets communicated on lined D4-D7 only, and D0-D3 are
-not connected.
-
-
-Logic analyzer setup
---------------------
-
-The capture was taken with an ASIX Sigma2 logic analyzer, sampling 8
-logic channels at a rate of 50MHz:
-
- Probe HD44780
- -------------------
- 1 IR (infrared remote control, idle, not HD44780 related)
- 2 RS (selects "commands" and "display data" mode)
- 3 RW (read/write, always low for write, fixed in HW)
- 4 E (enable, falling edge clocks data transfers)
- 5 D4 (data lines ...)
- 6 D5
- 7 D6
- 8 D7
-
-
-Data
-----
-
-See https://en.wikipedia.org/wiki/Hitachi_HD44780_LCD_controller for a
-list of display controller commands, and especially the 'Mode Selection'
-section which discusses the synchronization phase.
-
-The sequence demonstrates the following steps:
-- Synchronize to the LCD controller, cope with it being in any arbitrary
- state from previous execution.
-- Configure the LCD controller hardware to 4-bit mode, clear the screen
- and setup other parameters.
-- Print two text labels: "Hello LCD" and "counter", start printing
- counter values.
-
-When a dedicated HD44780 decoder is not available, the 'parallel' decoder
-can extract the most basic information: Clock on E (falling edge), D4-D7
-of the display corresponds to D0-D3 of the decoder (D4-D7 of the decoder
-are not connected). Words consist of 8 bits (span 2 bus cycles), and are
-in big endian format.
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