ZR36057 ZORAN [Zoran Corporation], ZR36057 Datasheet - Page 18

• Manufacturer Part Number: ZR36057
• Description: ENHANCED PCI BUS MULTIMEDIA CONTROLLER
• Manufacturer: ZORAN [Zoran Corporation]

Enhanced PCI Bus Multimedia Controller
input or output. When configured as an output, the host is able
to force the level of a pin through its corresponding register bit.
5.8 Interrupt Requests
The ZR36057’s interrupt manager connects to the various con-
ditions that may generate an interrupt request, enables or
disables them as specified in the Interrupt Control Register, and
drives the INTA output. It stores the corresponding status bits in
the Interrupt Status Register, and clears the status bits per host
instructions.
The ZR36057 can associate any one of the following events with
an interrupt request:
6.0 VIDEO INPUT PROCESSOR
6.1 Horizontal Filter
Prior to a significant horizontal down scaling of the input image,
it is advisable to apply one of the possible horizontal filters. The
filter type is selected through the HFilter parameter.
6.2 Horizontal/Vertical Downscaler
The horizontal and vertical down scalers are independent of
each other. The horizontal scaling ratio is configured through the
HorDcm parameter. HorDcm indicates the number of pixels to
drop out of every 64 consecutive pixels. HorDcm ranges from 0
to 63, where 0 represents the no scaling configuration (1:1 input
to output ratio).
The vertical scaling ratio is configured through the VerDcm
parameter. VerDcm indicates the number of lines to drop out of
every 64 consecutive lines. VerDcm ranges from 0 to 63, where
0 represents the no scaling configuration (1:1 input to output
ratio).
HFilter = 0
HFilter = 1 Filter 2: 3-tap luminance filter, 3-tap pre-interpolation
HFilter = 2 Filter 3: 4-tap luminance filter, 4-tap chrominance filter.
HFilter = 3 Filter 4: 5-tap luminance filter, 4-tap chrominance filter.
HFilter = 4 Filter 5: 4-tap luminance filter, 4-tap chrominance filter.
• A positive edge on the GIRQ1 input pin.
• A positive edge on the GIRQ0 input pin.
• MPEG mode - the code memory buffer pointer passing one
• JPEG modes - successful completion of a JPEG field or
of its report points.
frame process (in compression or decompression).
Filter 1: No luminance filter, 3-tap pre-interpolation filter
of chrominance.
chrominance filter.
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Each one of these events can be separately enabled or disabled
through the corresponding bit in the Interrupt Control Register.
An additional global enable bit enables or disables all interrupts.
When an interrupt-associated event occurs, two things happen:
Both the status bit(s) and INTA remain active, until the host
clears those status bits that are currently set. This is done by
writing a ‘1’ to those bits. When the host does that, the INTA
output signal returns to its passive, tri-state level.
If the host attempts to clear any of the Interrupt Status Register
bits at the same time that the interrupt logic attempts to set it
(because of an interrupt event), the set operation has priority
over the clear operation.
The vertical downscaler can operate in two ways. If DupFld=0 it
treats the top and bottom fields the same way. If DupFld=1 it
uses different line dropping topologies for the top and the bottom
fields, such that if the fields are equal (one field is actually dupli-
cated, like the output of most MPEG-1 decoders), then the total
loss of information is minimized. For example, when the video
source is a video digitizer, it is recommended to apply DupFld=0,
and when the video source is the ZR36110, and the CCIR size
is down scaled by half or more, it is recommended to apply
DupFld=1.
6.3 Color Space Converter
The color space converter converts the YUV input to RGB
format. The YUV2RGB parameter determines the type of
conversion:
When the 15- or 16-bit RGB format is selected, it is advisable to
apply the error diffusion option, in order to eliminate false
contours from the output image. This option is selected by the
ErrDif parameter (1 turns the error diffusion option on, while 0
turns it off).
YUV2RGB = 00b
YUV2RGB = 01b
YUV2RGB = 10b
YUV2RGB = 11b
• The corresponding bit in the Interrupt Status Register is set.
• If the interrupt is enabled, and the interrupts are enabled glo-
bally, then the INTA open-drain output pin is asserted to its
active-low level.
no conversion, output format is YUV 422.
conversion to RGB 8,8,8 (24-bit output)
conversion to RGB 5,6,5 (16-bit)
conversion to RGB 5,5,5 (15-bit)