User manual HITACHI HD44780U

[. . . ] HD44780U (LCD-II) (Dot Matrix Liquid Crystal Display Controller/Driver) Description The HD44780U dot-matrix liquid crystal display controller and driver LSI displays alphanumerics, Japanese kana characters, and symbols. It can be configured to drive a dot-matrix liquid crystal display under the control of a 4- or 8-bit microprocessor. Since all the functions such as display RAM, character generator, and liquid crystal driver, required for driving a dot-matrix liquid crystal display are internally provided on one chip, a minimal system can be interfaced with this controller/driver. A single HD44780U can display up to one 8-character line or two 8-character lines. [. . . ] In other words, the display disappears and the cursor or blinking goes to the left edge of the display (in the first line if 2 lines are displayed). It also sets I/D to 1 (increment mode) in entry mode. Return Home Return home sets DDRAM address 0 into the address counter, and returns the display to its original status if it was shifted. The cursor or blinking go to the left edge of the display (in the first line if 2 lines are displayed). Entry Mode Set I/D: Increments (I/D = 1) or decrements (I/D = 0) the DDRAM address by 1 when a character code is written into or read from DDRAM. The cursor or blinking moves to the right when incremented by 1 and to the left when decremented by 1. The same applies to writing and reading of CGRAM. S: Shifts the entire display either to the right (I/D = 0) or to the left (I/D = 1) when S is 1. If S is 1, it will seem as if the cursor does not move but the display does. The display does not shift when reading from DDRAM. Also, writing into or reading out from CGRAM does not shift the display. Display On/Off Control D: The display is on when D is 1 and off when D is 0. When off, the display data remains in DDRAM, but can be displayed instantly by setting D to 1. C: The cursor is displayed when C is 1 and not displayed when C is 0. Even if the cursor disappears, the function of I/D or other specifications will not change during display data write. The cursor is displayed using 5 dots in the 8th line for 5 × 8 dot character font selection and in the 11th line for the 5 × 10 dot character font selection (Figure 13). B: The character indicated by the cursor blinks when B is 1 (Figure 13). The blinking is displayed as switching between all blank dots and displayed characters at a speed of 409. 6-ms intervals when f cp or fOSC is 250 kHz. The cursor and blinking can be set to display simultaneously. (The blinking frequency changes according to fOSC or the reciprocal of fcp. For example, when fcp is 270 kHz, 409. 6 × 250/270 = 379. 2 ms. ) 193 HD44780U Cursor or Display Shift Cursor or display shift shifts the cursor position or display to the right or left without writing or reading display data (Table 7). This function is used to correct or search the display. [. . . ] All voltage values are referred to GND = 0 V. VCC B V1 A V5 A = VCC ­V5 B = VCC ­V1 A 1. 5 V B 0. 25 × A The conditions of V1 and V5 voltages are for proper operation of the LSI and not for the LCD output level. The LCD drive voltage condition for the LCD output level is specified as LCD voltage VLCD. 2. 5. VCC V1 V2 V3 V4V5 must be maintained. For die products, specified up to 75°C. [. . . ]