
Philips Semiconductors
Enhanced Video Out
PRODUCT SPECIFICATION
7-21
starts the EVO by setting the appropriate VO MMIO reg-
isters and the appropriate EVO MMIO registers.
VO_CTL.MODE must be set to the appropriate transfer
mode, appropriate addresses, address offsets, and im-
age timing registers and the associated control bits in the
control register must be set. Lastly, software sets
VO_CTL.VO_ENABLE to begin EVO operation. The
EVO transfers the image, data, or message as com-
manded. In video-refresh and data-streaming modes,
the EVO runs continuously. In message-passing mode,
the EVO runs only until the message has been trans-
ferred.
The EVO unit is reset by a TM1300 hardware reset, or by
a software reset, as described in Table 7-6 for the RE-
SET bit.
The VO_CLK signal is normally set as an output to drive
the data transfer for all modes at a programmable rate.
Table 7-8. EVO_CTL Register Fields
Register
Field
Description
EVO_CTL EVO_ENABLE
When set to 1, new EVO features are enabled. When set to 0 (the hardware reset value), the
EVO behaves exactly like a TM1000 VO unit. Default: 0.
FULL_BLENDING
Activates full 8-bit alpha blending when set to 1. When set to 0, only the original ve TM1000
blending levels are implemented (0%, 25%, 50%, 75%, 100%). Default: 0.
CLIPPING_ENABLE
When set to 1, the values stored in EVO_CLIP are used for the clipping of output data. Otherwise,
TM1000 default values (240 and 16 for Y, U and V) are used. Default: 0.
SYNC_STREAMING When set to 1 in data-streaming mode, VO_IO2 generates a DATA_VALID signal. See Section
7.17.2, “Data-transfer Modes”. Default: 0.
FIELD_SYNC
When set, VO_IO2 will generate frame synchronization signal that follows the eld number in
SAV/EAV codes (Field1 gives a low VO_IO2, Field2 gives a high VO_IO2). Default: 0.
GENLOCK
Activates Genlock mode when set to 1 and VO_CTL.SYNC_MASTER = 0. Default: 0.
KEY_ENABLE
When set, this bit activates chroma key. The overlay values (Y, U and V) are compared to the val-
ues stored in the EVO_KEY register. Bits that correspond to bits set in MASK_Y and MASK_UV
are ignored for the comparison. When there is an exact match between the pixel value and the
value in EVO_KEY register (less the bits selected by MASK_Y and MASK_UV), then the overlay
value is not present in the output stream, resulting in full transparency.
The key is 24 bits (Y, U and V are 8 bits each). Default: 0.
Table 7-9. EVO-Related MMIO Registers Fields
Register
Field
Description
EVO_MASK
MASK_Y
This 4-bit value is used to mask the four lower bits of the overlay Y component during the
chroma key process. Example: Setting MASK_Y to ‘1’ will eliminate the inuence of the
LSB of KEY_Y in the keying process.
MASK_UV
This 4-bit value is used to mask the four lower bits of the overlay U and V components
during the chroma key process. Example: Setting MASK_UV to ‘1’ will eliminate the
inuence of the LSB of KEY_U and KEY_V in the keying process.
EVO_CLIP
LOWER_CLIPY
A Y value lower or equal to LOWER_CLIPY is forced to LOWER_CLIPY. Default: 16.
HIGHER_CLIPY
A Y value higher or equal to HIGHER_CLIPY is forced to HIGHER_CLIPY. Default: 235.
LOWER_CLIPUV
An U or Y value less than or equal to LOWER_CLIPUV is forced to LOWER_CLIPUV.
Default: 16.
HIGHER_CLIPUV
An U or and an V value higher than or equal to HIGHER_CLIPUV is forced to
HIGHER_CLIPUV. Default: 240.
EVO_KEY
KEY_Y
Value compared to the Y component of the overlay for chroma keying.
KEY_U
Value compared to the U component of the overlay for chroma keying.
KEY_V
Value compared to the V component of the overlay for chroma keying.
EVO_SLVDLY
Number of VO_CLK cycles of internal delay for VO_IO2 in Genlock mode.
Table 7-10. Timing register recommended values
Register
Field
525/60
Value
625/50
Value
VO_CLOCK
FREQUENCY
0x855E,
E191
0x855E,
E191
VO_FRAME
FRAME_LENGTH
525
625
FIELD_2_START
264
311
FRAME_PRESET
1
VO_FIELD
F1_VIDEO_LINE
20
23
F2_VIDEO_LINE
283
336
F1_OLAP
2
F2_OLAP
3
–2 (0xE)
VO_LINE
FRAME_WIDTH
858
864
VIDEO_PIXEL_START
138
144