★ HARDWARE Manual ★ VDP2 User's Manual ★ Chapter 11 Priority Function
▲ Back ｜ Forward ▼
VDP2 User's Manual / Chapter 11 Priority Function

■ 11.3 Insert line color screen

The line color screen is a screen that does not have a priority number register and forcibly inserts it as the second image of the part where the specified screen is the top image and performs color calculation. At that time, in the part where the line color screen is inserted, the second image before insertion becomes the third image, and the third image becomes the image below it (force image). Figure 11.2 shows the insertion of a line color screen.

Figure 11.2 Inserting a line color screen

● Line color screen enable register

The line color screen enable register specifies whether to insert a line color screen when each screen reaches the top image. A write-only 16-bit register located at address 1800E8H. After turning on the power or resetting, the value will be cleared to 0, so be sure to set it.

LNCLEN 1800E8H
 15
 14
 13
 12
 11
 Ten
 09 09
 08 08
 ---
 ---
 ---
 ---
 ---
 ---
 ---
 ---

 07 07
 06 06
 05 05
 04
 03 03
 02 02
 01 01
 00
 ---
 ---
 SPLCEN
 R0LCEN
 N3LCEN
 N2LCEN
 N1LCEN
 N0LCEN

Line color enable bit : Line color enable bit
(N0LCEN, N1LCEN, N2LCEN, N3LCEN, R0LCEN, SPLCEN) Specifies whether to insert a line color screen when each screen becomes the top image.

N0LCEN 1800E8H Bit 0 For NBG0 (or for RBG1)
N1LCEN 1800E8H Bit 1 For NBG1 (or for EXBG)
N2LCEN 1800E8H Bit 2 For NBG2
N3LCEN 1800E8H Bit 3 For NBG3
R0LCEN 1800E8H Bit 4 For RBG0
SPLCEN 1800E8H Bit 5 For sprites

xxLCEN process
0 Do not insert line color screen when the corresponding screen becomes the top image
1 Insert a line color screen when the corresponding screen becomes the top image
Note The bit name xx can be N0, N1, N2, N3, R0, or SP.

The line color screen is inserted only in the second image where the screen specified to be inserted becomes the top image.
Sprites can only be specified for the entire sprite. If you want to specify for each character, control with the value of the color calculation ratio for each character.
It cannot be used at the same time as the blur calculation function.

▲ Back ｜ Forward ▼
★ HARDWARE Manual ★ VDP2 User's Manual ★ Chapter 11 Priority Function
Copyright SEGA ENTERPRISES, LTD., 1997