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| author | Gerhard Sittig <gerhard.sittig@gmx.net> | 2019-01-20 11:12:17 +0100 |
|---|---|---|
| committer | Gerhard Sittig <gerhard.sittig@gmx.net> | 2019-01-20 11:12:17 +0100 |
| commit | 2725ee35d4fa0d30e176ed2728fee95a64934cda (patch) | |
| tree | 1edc91e5670048c3649b0eb5cb4327800b9c484a /hd44780/README | |
| parent | 226e72ccfbeed40715c0ae5e1b75e80af174e53a (diff) | |
| download | sigrok-dumps-2725ee35d4fa0d30e176ed2728fee95a64934cda.tar.gz sigrok-dumps-2725ee35d4fa0d30e176ed2728fee95a64934cda.zip | |
hd44780: move HD44780 dump into the display/ subdirectory
Diffstat (limited to 'hd44780/README')
| -rw-r--r-- | hd44780/README | 51 |
1 files changed, 0 insertions, 51 deletions
diff --git a/hd44780/README b/hd44780/README deleted file mode 100644 index 9dc2e29..0000000 --- a/hd44780/README +++ /dev/null @@ -1,51 +0,0 @@ -------------------------------------------------------------------------------- -Hitachi HD44780 display controller, 4-bit mode, initialization sequence -------------------------------------------------------------------------------- - -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. |