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Single 14 Segment Display Driver with Limited ASCII Decoder
0.1
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Top entity of the display driver. More...
Entities | |
| arch | architecture |
| Architecture definition of the DisplayDriverwDecoder_Top. More... | |
Libraries | |
| ieee | |
Use Clauses | |
| std_logic_1164 | |
| numeric_std | |
Ports | |
| clk | in std_logic |
| input clock, xx MHz. | |
| reset | in std_logic |
| active high | |
| ascii_in | in std_logic_vector ( 7 downto 0 ) |
| wr_en | in std_logic |
| active high write enable to store the ASCII code in a register | |
| disp_data | out std_logic_vector ( 14 downto 0 ) |
| disp_sel | out std_logic |
Top entity of the display driver.
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Port |
ASCII symbols are coded in 1B having values from 0x00 to 0x7F. Current implementation uses 104-Character ASCII Font Map described in MAX6955 Datasheet. https://datasheets.maximintegrated.com/en/ds/MAX6955.pdf The MSB is used to light the display dot. For example if you want to display H the code will be 0x48 (or 01001000b). If you want to display H. the code will be 0xC8 (or 11001000b).
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Port |
Typically the data fed to display (single or multiple) is provided for single display at a time. If multiple displays are required disp_sel signal must be provided (according typical dynamic display indication).
| Bit Number | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Display Segment | a | b | c | d | e | f | g1 | g2 | h | i | j | k | l | m | dp |
Note that there is no standard way to name the segments. Current data bits correspondt to display segments according this picture: https://www.maximintegrated.com/en/images/appnotes/3211/3211Fig02.gif
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Port |
If more displays needs to be fed change disp_sel to vector with length equal to number of displays. Use principles of the standard dynamic indication: provide data then enable the displays sequentially. If brightness control is desired just AND the selector and the PWM controller output.
1.8.13