Chips&Tech PC Video Video Windowing Controller
82c9001A
The CT 82c9001 is used for framegrabbers like the Video Blaster.
index 00h (R/W): I/O Address Register
bit 1-7 These bits determine the lower 8 bits of the address the card
responds at. If CS/ is low on RESET this register is initialised to
0D6h. If CD/ is high on RESET the register is loaded with the value
on the databus during the first write to the chip.
index 01h (R/W): Memory Access Register
bit 4 If set the VRAM Write Mask is enabled.
index 06h (R/W): Linear Memory Base Address Register
bit 0-3 Starting Address of the linear in 1MB units.
index 07h (R/W): Data Mask Register, Luminance Data
bit 0-7 A set bit enables the corresponding bits in each byte of the
Luminance data to be modified during data acquisition.
index 08h (R/W): Data Mask Register, Chrominance Data
bit 0-7 A set bit enables the corresponding bits in each byte of the
Chrominance data to be modified during data acquisition.
index 09h (R/W): Interrupt Mask Register
bit 0 If set Video Even Vsync Interrupt is enabled.
1 If set Video Odd Vsync Interrupt is enabled.
2 (R) Video Vsync
3 (R) Video Field. 0=Even, 1=Odd
4 (R) VGA VSync
5 (R) VGA HSync
index 10h-13h General Purpose I/O Register 0-3
index 18h (R/W): General Purpose I/O Control Register
bit 0 I2C Bus Clock. Reads/Writes the I2CK pin
1 I2C Bus Data. Reads/Writes the I2CO pin
2 I2C bus read back input pin I2CI. This pin should be tied to I2CO.
4 If clear enables decode of R10 on GPIO0.
5 If clear SCSMAT is output on GPOI1, else enables decode of R11 on
GPIO1.
6 If clear enables decode of R12 on GPIO2.
7 If clear enables decode of R13 on GPIO3.
index 20h (R/W): Video Acquisition Mode Register
bit 0 If set start video acquisition. Type of acquisition determined by
bits 1-3. If set Stop Acquisition and allow access to video memory.
After an Acquisition this bit should be tested before accessing
video memory.
1 If clear Continuos Video Acquisition, if set Acquire only a field or
frame (see bit 2). Bit 0 cleared at the end of acquisition.
2 If clear Acquire a video frame (full picture), if set (only for
interlaced video) acquire only a field.
3 If clear Acquire an even (first) field, if set Acquire an odd
(second) field.
4 If set Video Hsync is active high.
5 If set Video Vsync is active high.
7 If clear video input is interlaced.
index 21h (R/W): Acquisition Window Control Register
bit 0 If set Video Input Cropping is enabled.
1 If set capture outside cropping window, if clear capture inside
cropping window.
2 If set Horizontal Video Input Scaling is enabled.
3 If set Vertical Video Input Scaling is enabled.
4 Video Input Data Multiplexing. If set the input is non-multiplexed
(i.e.. RGB), if clear input is multiplexed (i.e.. YUV).
5 Multiplexing Ratio. Only active if bit 4 is 0.
0: 4:1:1 or 2:1:1, 1: 4:2:2
6 If set select XFLD input for field signal, if clear use internally
generated field signal.
7 If set invert field signal polarity.
index 22h-23h W(R/W): Acquisition Window, X-Start Register
bit 0-9 Horizontal Start of Acquisition Window measured in pixel clocks from
the trailing edge of Hsync.
index 24h-25h W(R/W): Acquisition Window, Y-start Register
bit 0-9 Vertical Start of Acquisition Window measured in scanlines from the
trailing edge of (Vsync + V Start Adjust (index 30h)).
index 26h-27h W(R/W): Acquisition Window, X-end Register
bit 0-9 Horizontal End of Acquisition Window measured in pixel clocks from
the trailing edge of Hsync.
index 28h-29h W(R/W): Acquisition Window, Y-end Register
bit 0-9 Vertical Start of Acquisition Window measured in scanlines from the
trailing edge of (Vsync + V Start Adjust (index 30h)).
index 2Ah-2Ch 3(R/W): Acquisition Address Register
bit 0-19 Linear Address of the start of the Acquisition Buffer.
1024 bytes are reserved for each line.
index 2Dh (R/W): Acquisition Horizontal Scaling Register.
bit 0-5 If enabled by index 21h bit 2, this is the number of pixels (1-63)
written for each 64 input pixels.
index 2Eh (R/W): Acquisition Vertical Scaling Register.
bit 0-5 If enabled by index 21h bit 3, this is the number of lines (1-63)
written for each 64 input lines.
index 2Fh (R/W): Scaling Field Adjust Register.
bit 0-6 Modifies the scaling value for the odd field during acquisition.
This is a diagnostic register and should normally be set to the same
value as index 2Eh.
index 30h (R/W): Input Video Start Adjust
bit 0-5 Number of scanlines from the trailing edge of Vsync to the start of
the active video frame. Should always be non-zero.
index 38h (R/W): Scaling Control Register.
bit 0-1 Chroma Multiplex Adjust Bits.
2 Y-Over-Write-Mode. When acquiring from an interlaced source with a
scaling of less than 1/2, this bit and the Field Grab bit (index 20h
bit 2) should be set to write a scaled image from only one of the
video fields.
3 X-Max Enable. If set prevents wrap around of memory X-address.
4 Y-Max Enable. If set prevents wrap around of memory Y-address.
Should be set for PAL video.
7 Fast Write Enable. If set CPURDY is asserted one clock earlier than
normal.
index 40h (R/W): Display Area Control Register
bit 0 If clear Overlay Window using an X-Y Window is enabled.
1 If clear Overlay Window using Color Keying is enabled.
2 If set display the Display Frame Buffer Data in the Non-color key or
non X-Y Window area, else display VGA data.
3 If set display Frame Buffer Data in the X-Y Window area, else
display VGA data. Only active if bit 0 is set.
4 If set display Frame Buffer Data in the Color Key area, else display
VGA data. Only active if bit 1 is set.
5 If set display Frame Buffer Data in the X-Y Window or Color Key
area, else display VGA data.
6-7 Skew between VGA data input and the multiplexer control output in
VGA clocks: 0: 2 VGA clocks, 1: 3 clocks, 2: 4 clocks, 3: 5 clocks.
index 41h-42h W(R/W): Display Window, X-start Register
bit 0-9 Horizontal start of the Display Window in pixels from the trailing
edge of the VGA Hsync.
index 43h-44h W(R/W): Display Window, Y-start Register
bit 0-9 Vertical start of the Display Window in lines from the trailing edge
of the VGA Vsync
index 45h-46h W(R/W): Display Window, X-end Register
bit 0-9 Horizontal end of the Display Window in pixels from the trailing
edge of the VGA Hsync.
index 47h-48h W(R/W): Display Window, Y-end Register
bit 0-9 Vertical end of the Display Window in lines from the trailing edge
of the VGA Vsync
index 49h (R/W): X-Panning, Low Register
bit 0-7 Lower 8 bits of the Column Offset (*2) loaded into the VRAM during
the data transfer cycle. For 4:1:1 coding bit 0 should be 0.
index 4Ah (R/W): Y-Panning, Low Register
bit 0-7 Lower 8 bits of the Row Offset loaded into the VRAM for the first
active display line.
index 4Bh (R/W): X,Y Panning, High Register
bit 0 Bit 8 of the X-panning value. The lower 8 bits are in index 49h.
4 Bit 8 of the Y-panning value. The lower 8 bits are in index 4Ah.
index 4Ch (R/W): Shift Clock Start Register
bit 0-6 End of the display blank from the trailing edge of the VGA Hsync.
index 4Dh (R/W): Sync Polarity Register
bit 0-1 Horizontal Zoom. 0: No Zoom, 1: x2, 2: x4, 3: x8
2-3 Vertical Zoom. 0: No Zoom, 1: x2, 2: x4, 3: x8
4 VGA Hsync Polarity. If set the VGA Hsync is active high.
5 VGA Vsync Polarity. If set the VGA Vsync is active high.
index 4Eh (R/W): Color Compare Register
bit 0-7 The color to compare with.
index 4Fh (R/W): Color Mask Register
bit 0-7 Only the bit positions, which are 0 in this register are used in
color comparisons
index 50h (R/W): Display Window Interlace Control
bit 0 If set the Display Window is interlaced.
1 If set use the VFLD input for the display window field signal,
rather than the internally generated field signal.
2 If set invert the Display Window field signal polarity.
3-4 Replication of fields.
0,2: No replication.
1: Replicate even field.
3: Replicate odd field.
index FFh (R/W): Chips Version/Enable Register
bit 0 (W) PC Video Global Enable. Must be set to enable other registers.
1 (W) Enable memory if set.
4-7 (R) Silicon revision. 0 for initial release.