TM-1300 Datasheet, PDF (105/533 Pages) NXP Semiconductors – Programmable Media Processor

Enhanced Video Out
Chapter 7
by Marc Duranton, Dave Wyland, Gert Slavenburg
7.1 ENHANCED VIDEO OUT SUMMARY
The TM1300 Enhanced Video Out (EVO) improves on
the design of the TM1000 Video Out (VO) unit while
maintaining binary-compatibility. TM1300 EVO is fully
backward compatible with TM1100, and has been ex-
tended to support byte data rates up to 81-MHz and im-
prove the Genlock mode. The summary of new EVO fea-
tures versus TM1000 includes:
• Internal clock generator (DDS) has reduced jitter
• Full alpha blending supports 129-levels
• Chroma keying
• Frame synchronization can be internally or externally
generated (Genlock mode)
• External frame sync. follows the field number gener-
ated in the EAV/SAV code
• Programmable YUV output clipping
• Data-valid signal generated in data-streaming mode
• In message passing mode, message length can
range from one word (4 bytes) up to 16 MB.
7.2 ABOUT THIS DOCUMENT
This chapter describes the TM1300 EVO unit which ex-
tends and improves the design of the TM1000 VO unit,
and consolidates the changes introduced in the TM1100.
Please refer to the TM1000 databook for a description of
the VO unit’s functionality.
7.3 BACKWARD COMPATIBILITY
The EVO is functionally compatible with the TM1000 VO
unit. All TM1000 VO features are supported exactly in
the same fashion by the TM1300 EVO. Software written
for the TM1000 VO can control the TM1300 EVO without
modification (with the exception of the Genlock mode
which now requires EVO_CTL.GENLOCK to be set to 1
in addition to VO_CTL.SYNC_MASTER = 0).
All new features and improvements are selectively en-
abled by setting bits in the new EVO_CTL MMIO regis-
ter, described in Section 7.16.4. A method to determine
the existence of new EVO registers is given in
Section 7.16.1.
The new TM1300 EVO features are disabled on hard-
ware reset in order to remain hardware-compatible with
the TM1000 VO. So it is assumed throughout this chap-
ter that all new functions controlled by EVO_CTL are en-
abled by software. Any new software should use the new
EVO modes. Please refer to the TM1000 databook for a
description of the VO unit’s funtionality.
7.4 FUNCTION SUMMARY
The TM1300 EVO generates and transmits continuous
digital video images. It can connect to an off-chip video
subsystem such as a digital video encoder chip (e.g., the
Philips SAA7125 DENC digital encoder), a digital video
recorder, or the video input of another TM1300 through
a CCIR 656-compatible byte-parallel video interface.
See Figure 7-1, Figure 7-1, and Figure 7-2.
The EVO can either supply video pixel clock and syn-
chronization signals to the external interface or synchro-
nize to signals received from the external interface (Gen-
lock mode).
PAL, NTSC, 16:9 and other video formats including dou-
ble pixel-rate, non-interlaced video formats are support-
ed through programmable registers which control pixel
clock frequency and video field or frame format.
The EVO can combine a background video image from
SDRAM with an optional foreground graphics overlay im-
age from SDRAM using 129-level, per-pixel alpha blend-
ing. The composite result is sent out as continuous vid-
eo. Video image data is taken from a planar memory
format, with separate Y, U and V planes in memory in
YUV 4:2:2 or 4:2:0 format. The optional graphics overlay
is taken from a pixel-packed YUV 4:2:2+α data structure
in memory.
The EVO can also be used to stream continuous data
(data-streaming mode) or send unidirectional messages
(message-passing mode) from one TM1300 to another.
In data-streaming mode, the EVO generates a continu-
ous stream of arbitrary byte data using internal or exter-
nal clocking. Dual buffers allow continuous data stream-
ing in this mode by allowing the DSPCPU to set up a
buffer while another is being emptied by the EVO. Data-
valid signals are generated on VO_IO1 and VO_IO2 to
synchronize data streaming to other TM1300 data re-
ceivers.
In message-passing mode, unidirectional messages can
be sent to the Video In (VI) port(s) of one or more
TM1300s. Start and end-of-message signals are provid-
ed to synchronize message passing to other TM1300
message receivers.
PRODUCT SPECIFICATION
7-1