AMD Geode SC3200 - Manual (Page 334)

334 AMD Geode™ SC3200 Processor Data Book
Video Processor Module - Video Processor Registers - Function 4 32581C
Offset 08h-0Bh Video X Position Register (R/W) Reset Value: 00000000h
Provides the window X position. This register is programmed relative to CRT horizontal sync input (not physical screen position).
Note: H_TOTAL and H_SYNC_END are values programmed in the GX1 module’s Display Controller Timing registers
(GX_BASE+Memory Offset 8330h[26:19] and 8338h[10:3], respectively). The value of (H_TOTAL – H_SYNC_END) is some-
times referred to as “horizontal back porch”. For more information, see the AMD Geode™ GX1 Processor Data Book.
31:28 Reserved.
27:16 VID_X_END (Video X End Position). Represents the horizontal end position of the video window (not inclusive). This value
is calculated according to the following formula:
Value = Desired screen position + (H_TOTAL – H_SYNC_END) – 13.
15:12 Reserved.
11:0 VID_X_START (Video X Start Position). Represents the horizontal start position of the video window. This value is calcu-
lated according to the following formula:
Value = Desired screen position + (H_TOTAL – H_SYNC_END) – 14.
Offset 0Ch-0Fh Video Y Position Register (R/W) Reset Value: 00000000h
Provides the window Y position. This register is programmed relative to CRT vertical sync input (not physical screen position).
Note: V_TOTAL and V_SYNC_END are values programmed in the GX1 module’s Display Controller Timing registers
(GX_BASE+Memory Offset 8340h[26:16] and 8348h[26:16], respectively). The value of (V_TOTAL – V_SYNC_END) is some-
times referred to as “vertical back porch”. For more information, see the AMD Geode™ GX1 Processor Data Book.
31:27 Reserved.
26:16 VID_Y_END (Video Y End Position). Represents the vertical end position of the video window (not inclusive). This value is
calculated according to the following formula:
Value = Desired screen position + (V_TOTAL – V_SYNC_END) + 2.
15:11 Reserved
10:0 VID_Y_START (Video Y Start Position). Represents the vertical start position of the video window. This value is calculated
according to the following formula:
Value = Desired screen position + (V_TOTAL – V_SYNC_END) + 1.
Offset 10h-13h Video Upscale Register (R/W) Reset Value: 00000000h
Provides horizontal and vertical upscale factors of the window.
31:30 Reserved.
29:16 VID_Y_SCL (Video Y Scale Factor). Represents the vertical upscale factor of the video window according to the following
formula:
VID_Y_SCL = 8192 * (Ys - 1) / (Yd - 1)
where:
Ys = Video source vertical size in pixels
Yd = Video destination vertical size in pixels
Note: Upscale factor must be used. Yd is equal or bigger than Ys. If no scaling is intended, set to 2000h. The actual scale
factor used is VID_Y_SCL/8192, but the formula above fits a given source number of lines into a destination win-
dow size.
Note: When progressive mixing/blending is programmed (F4BAR0+Memory Offset 4Ch[9] = 0) and the video data is
interlaced, this register should be programmed to 1000h to double the vertical lines,
15:14 Reserved.
13:0 VID_X_SCL (Video X Scale Factor). Represents horizontal upscale factor of the video window according to the following
formula:
VID_X_SCL = 8192 * (Xs - 1) / (Xd - 1)
where:
Xs = Video source horizontal size in pixels
Xd = Video destination vertical size in pixels
Note: Upscale factor must be used. Xd is equal or bigger than Xs. If no scaling is intended, set to 2000h. The actual scale
factor used is VID_X_SCL/8192, but the formula above fits a given source number of pixels into a destination win-
dow size.
Table 7-7. F4BAR0+Memory Offset: Video Processor Configuration Registers (Continued)
Bit Description