LC78711E Datasheet, PDF (16/43 Pages) Sanyo Semicon Device – Graphics Display Processor

LC78711E
Writing graphics data
[A] Set up point (Xs, Ys): X is a 9-bit address.
[B] Set up point (Xe, Ye): Y is an 8-bit address.
1. Begin writing color codes from the origin coordinate address (Xs, Ys).
2. If the X direction address (Xs) matches the endpoint address (Xe), reset the X address to the origin address (Xs). At
the same time, increment the Y address by one count.
3. Terminate writing when the endpoint address (Xe, Ye) is reached.
• At termination, reset the address to the origin address (Xs, Ys) and exit.
• Terminate writing even if the CE pin has gone low. In this case, the address will be set to the endpoint address plus
one and the algorithm will exit.
• The address manipulations described above, are for the case where automatic address incrementing has been set up
by command.
1. When writing to the graphics display area, specify the address of the origin [A] to be 6 and the address of the
endpoint [B] to be 11.
2. When writing to a rectangular area, the origin [A] and the endpoint [B] can be set to arbitrary values.
When filling is specified by command, RAM data will be set to the first specified color code.
In this case, it suffices to write the color code that was specified at that point. However, add the condition that the
color code setting must not be changed during the fill operation.
3. When writing a straight line, set either the X (horizontal) values or Y (vertical) values of the origin [A] and endpoint
[B] to the same value.
For example, to draw a straight line in the vertical direction, set the origin [A] to (Xs, Ys) and set the endpoint [B] to
(Xs, Ye).
To draw a straight line in the horizontal direction, set the origin [A] to (Xs, Ys) and set the endpoint [B] to (Xe, Ys).
Filling must be specified by command to write straight lines.
4. Set up the addresses as follows to write scroll data.
For example,
To scroll down, specify 2 as the origin [A] and 7 as the endpoint [B].
To scroll right, specify 5 as the origin [A] and 9 as the endpoint [B].
To scroll left, specify 7 as the origin [A] and 12 as the endpoint [B].
To scroll up, specify 10 as the origin [A] and 15 as the endpoint [B].
Reading out color codes for specific bits
It is possible to read out (not write) the color code for a given dot by using a command to set the origin address (Xs, Ys).
Executing the read out command latches the data into the serial output shift register. The command manipulation
terminates when the data for a single dot has been read out. (The command register is reset.)
Graphics display priority order
1. Cross cursor
2. Sprite A pattern
3. Sprite B pattern
4. Graphics screen
5. Border screen
6. Background screen (not displayed during graphics display)
Note: There are cases where the same pattern is displayed for sprite patterns A and B. Thus the LC78711E may be in a
state of accessing the same sprite RAM. Therefore, a time difference must be set up for the sprite pattern accesses
(reads) for the A and B patterns.
No. 5476-16/43