PXD20RM Datasheet, PDF (1564/1628 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

EAV
SAV
Timing Reference Signals
Figure 47-17. Interface Data Stream of ITU-R BT.656-4
Each timing reference signal consists of a four-word sequence in the following format: FF 00 00 XY.
Values are expressed in hexadecimal notation. Value FF and 00 are reserved to be used in the timing
reference signals.
The first three words are a fixed preamble. The fourth word contains information defining field 2
identification, the state of field blanking, and the state of line blanking. The assignment of bits within the
timing reference signal is shown in Table 47-18.
Table 47-18. Video Timing Reference Codes
Data Bit Number
First Word
(FF)
Second Word
(00)
Third Word
(00)
Fourth Word
(XY)
9(MSB)
1
0
0
1
8
1
0
0
F(0: field 1, 1: field 2)
7
1
0
0
V(0: elsewhere, 1: field blanking)
6
1
0
0
H(0: in SAV, 1: in EAV)
5
1
0
0
P3
4
1
0
0
P2
3
1
0
0
P1
2
1
0
0
P0
1
1
0
0
0
0
1
0
0
0
In above table, bits P0, P1, P2, P3 have states dependent on the states of the bits F, V and H. At the receiver
side this arrangement permits one-bit errors to be corrected and two-bit errors to be detected.
Note that when used in progressive video mode (instead of interlaced mode), where frames are transfered
versus odd and even fields, the F bit can be either ignored or considered as indication of frames.
Refer to the ITU-R BT.656-4 recommendation for more details.
47-16
PXD20 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
Freescale Semiconductor