New Micros NMIY-0031, Manual

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N M I Y - 0 0 3 1 P R O G R A M M I N G
Cursor/Display Shift moves the cursor and shifts the display without changing data. Cursor
move direction is also controlled.
10 Move cursor to the left 18 Shift data to left
14 Move cursor to the right 1C Shift data to the right
Function Set sets the number of display lines and selects character format.
30 Set 1 line display with
5x7 dot format. 38 Set 2 line display with 5x7 dot
format.
34 Set 1 line display with
5x10 dot format. 3C Set 2 line display with 5x10 dot
format.
DDRAM Address Set allows the cursor address to be manipulated.
1xxx xxxx binary
where x is a
binary digit Character position addresses are:
80 to 8F(16) to 93(20) to A7(40) for the first line
C0 to CF(16) to D3(20) TO E7(40) for the second line
(Upper address limits are shown for 16, 20, and 40 character per line LCD’s)
Today most LCD’s use the same controller chip, the Hitachi HD44780, or equivalent, regardless
of display line length up to 40 characters and 4 lines. Data memory (DDRAM) will hold up to 40
characters on each line while displaying only a contiguous segment of that line equal to the
number of display characters. The position addresses are shown above where the 16, 20 and 40
character display line end addresses are noted. Note that these address limits assume that the first
character displayed is the first character of that line in memory. Using the shift feature, the first
character displayed can be moved within the memory space in DDRAM. For example, a 16
character per line display could display positions 98 to A7 when shifted fully to the right. See
Entry Mode Set for shift instructions. Addresses on each line wrap to the beginning of that line.
That is, A7 is adjacent to 80 and E7 is adjacent to C0. LCD’s with fewer than 40 characters per
line can still store a full 40 characters, but will display only 16 or 20 of them at a time. The display
window’s position will be the same for all lines of the display.
LCD’s have a command and a data address. The LCD data address is FFF9. When data is
written to this address it will be displayed according to the display mode previously selected.
Display characters are from an enhanced ASCII character set. Numerals, upper and lower case
roman letters, and punctuation marks are among the common characters supported.