L64780 LSI Logic Corporation, L64780 Datasheet - Page 66

• Manufacturer Part Number: L64780
• Description: Dvb-t Cofdm Demodulator Technical Manual 2/00
• Manufacturer: LSI Logic Corporation

4.3.3 Address Line 0x04
4-14
RES
FRAME_NB
Register Descriptions
0x04
RES
7
Reserved
This bit is reserved.
COFDM Frame Number
When this register is read, these bits provide the last
value received by the channel, using the TPS signalling
information. The values are:
The initial condition for the FRAME_NB is 0b00 (Frame 0).
Internally, there are three TPS registers:
If the AUTO_MODE_ENABLE bit is set, then every time
a valid TPS is received and a super-frame boundary is
detected, the demodulator copies the contents of the
received TPS register into the active TPS register (and
changes the current mode of the DTTV receiver if the
received TPS changes).
If the received TPS (stored in the received TPS register)
and the current mode of the DTTV demodulator (held in
FRAME_NB[1:0]
The first (0x02, the active TPS register) contains the
current mode of the DTTV demodulator.
The second (the next TPS register, 0x03) is written by
writing to the TPS register in the register map. When
the “change mode” command is issued, the next TPS
register is copied into the active TPS register, and this
becomes the current mode of the demodulator.
The third register (the received TPS register, 0x04)
contains a copy of the last valid TPS that was
received in the input signal. This register can be read
by reading from the TPS register in the register map.
FRAME_NB
0
0
1
1
6
5
0
1
0
1
Definition
Frame 0
Frame 1
Frame 2
Frame 3
4
HIERARCHY
2
1
QAMTYPE
R [6:5]
0
7