Datasheet HD44780U (LCD-II) (Hitachi) - 10
| Manufacturer | Hitachi |
| Description | Dot Matrix Liquid Crystal Display Controller/Driver |
| Pages / Page | 60 / 10 — HD44780U. Display Data RAM (DDRAM). Figure 1 DDRAM Address. Figure 2 … |
| File Format / Size | PDF / 330 Kb |
| Document Language | English |
HD44780U. Display Data RAM (DDRAM). Figure 1 DDRAM Address. Figure 2 1-Line Display
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HD44780U Display Data RAM (DDRAM)
Display data RAM (DDRAM) stores display data represented in 8-bit character codes. Its extended capacity is 80 × 8 bits, or 80 characters. The area in display data RAM (DDRAM) that is not used for display can be used as general data RAM. See Figure 1 for the relationships between DDRAM addresses and positions on the liquid crystal display. The DDRAM address (A ) is set in the address counter (AC) as hexadecimal. DD • 1-line display (N = 0) (Figure 2) When there are fewer than 80 display characters, the display begins at the head position. For example, if using only the HD44780, 8 characters are displayed. See Figure 3. When the display shift operation is performed, the DDRAM address shifts. See Figure 3. High order Low order bits bits Example: DDRAM address 4E AC AC6 AC5 AC4 AC3 AC2 AC1 AC0 1 0 0 1 1 1 0 (hexadecimal)
Figure 1 DDRAM Address
Display position (digit) 1 2 3 4 5 79 80 DDRAM 00 01 02 03 04 . 4E 4F address (hexadecimal)
Figure 2 1-Line Display
Display position 1 2 3 4 5 6 7 8 DDRAM 00 01 02 03 04 05 06 07 address For shift left 01 02 03 04 05 06 07 08 For shift right 4F 00 01 02 03 04 05 06
Figure 3 1-Line by 8-Character Display Example
10 Document Outline Description Features Ordering Information HD44780U Block Diagram HD44780U Pin Arrangement (FP-80B) HD44780U Pin Arrangement (TFP-80F) HD44780U Pad Arrangement HD44780U Pad Location Coordinates Pin Functions Function Description Interfacing to the MPU Reset Function Instructions Instruction Description Interfacing the HD44780U Power Supply for Liquid Crystal Display Drive Relationship between Oscillation Frequency and Liquid Crystal Display Frame Frequency Instruction and Display Correspondence Initializing by Instruction Absolute Maximum Ratings DC Characteristics AC Characteristics Bus Timing Characteristics Interface Timing Characteristics with External Driver Power Supply Conditions Using Internal Reset Circuit DC Characteristics AC Characteristics Bus Timing Characteristics Interface Timing Characteristics with External Driver Power Supply Conditions Using Internal Reset Circuit Electrical Characteristics Notes Load Circuits Timing Characteristics
Display data RAM (DDRAM) stores display data represented in 8-bit character codes. Its extended capacity is 80 × 8 bits, or 80 characters. The area in display data RAM (DDRAM) that is not used for display can be used as general data RAM. See Figure 1 for the relationships between DDRAM addresses and positions on the liquid crystal display. The DDRAM address (A ) is set in the address counter (AC) as hexadecimal. DD • 1-line display (N = 0) (Figure 2) When there are fewer than 80 display characters, the display begins at the head position. For example, if using only the HD44780, 8 characters are displayed. See Figure 3. When the display shift operation is performed, the DDRAM address shifts. See Figure 3. High order Low order bits bits Example: DDRAM address 4E AC AC6 AC5 AC4 AC3 AC2 AC1 AC0 1 0 0 1 1 1 0 (hexadecimal)
Figure 1 DDRAM Address
Display position (digit) 1 2 3 4 5 79 80 DDRAM 00 01 02 03 04 . 4E 4F address (hexadecimal)
Figure 2 1-Line Display
Display position 1 2 3 4 5 6 7 8 DDRAM 00 01 02 03 04 05 06 07 address For shift left 01 02 03 04 05 06 07 08 For shift right 4F 00 01 02 03 04 05 06
Figure 3 1-Line by 8-Character Display Example
10 Document Outline Description Features Ordering Information HD44780U Block Diagram HD44780U Pin Arrangement (FP-80B) HD44780U Pin Arrangement (TFP-80F) HD44780U Pad Arrangement HD44780U Pad Location Coordinates Pin Functions Function Description Interfacing to the MPU Reset Function Instructions Instruction Description Interfacing the HD44780U Power Supply for Liquid Crystal Display Drive Relationship between Oscillation Frequency and Liquid Crystal Display Frame Frequency Instruction and Display Correspondence Initializing by Instruction Absolute Maximum Ratings DC Characteristics AC Characteristics Bus Timing Characteristics Interface Timing Characteristics with External Driver Power Supply Conditions Using Internal Reset Circuit DC Characteristics AC Characteristics Bus Timing Characteristics Interface Timing Characteristics with External Driver Power Supply Conditions Using Internal Reset Circuit Electrical Characteristics Notes Load Circuits Timing Characteristics
