MSP 44x8G
PRELIMINARY DATA SHEET
6.4.1. NICAM Mode Control/Additional Data Bits
Register
6.4.2. Additional Data Bits Register
Contains the remaining 8 of the 11 additional data bits.
The additional data bits are not yet defined by the
NICAM 728 system.
NICAM operation mode control bits and A[2:0] of the
additional data bits.
Format:
Format:
MSB
C_AD_BITS 00 23hex
LSB
MSB
7
ADD_BITS 00 38hex
LSB
0
11
...
...
7
6
5
4
3
2
1
0
6
5
4
3
2
1
Auto
_FM
A[2] A[1] A[0]
C4
C3
C2
C1
S
A[10]
A[9]
A[8]
A[7]
A[6]
A[5]
A[4]
A[3]
Important: “S” = Bit[0] indicates correct NICAM-syn-
chronization (S = 1). If S = 0, the MSP 4418/4458G
has not yet synchronized correctly to frame and
sequence, or has lost synchronization. The remaining
read registers are therefore not valid. The MSP mutes
the NICAM output automatically and tries to synchro-
nize again as long as any NICAM standard is selected
by the STANDARD SELECT register.
6.4.3. CIB Bits Register
CIB bits 1 and 2 (see NICAM 728 specifications).
Format:
MSB
CIB_BITS 00 3Ehex
LSB
0
7
x
6
x
5
x
4
x
3
x
2
x
1
The operation mode is coded by C4-C1 as shown in
Table 6–10.
CIB1
CIB2
Table 6–10: NICAM operation modes as defined by
the EBU NICAM 728 specification
6.4.4. NICAM Error Rate Register
C4 C3 C2 C1 Operation Mode
ERROR_RATE
Error free
00 57hex
0
0
0
0
0
0
0
0
1
0
1
0
Stereo sound (NICAMA/B),
independent mono sound (FM1)
0000hex
07FFhex
maximum error rate
Two independent mono signals
(NICAMA, FM1)
Three independent mono channels
(NICAMA, NICAMB, FM1)
Average error rate of the NICAM reception in a time
interval of 182 ms, which should be close to 0. The ini-
tial and maximum value of ERROR_RATE is 2047.
This value is also active if no NICAM-standard is
selected. Since the value is achieved by filtering, a cer-
tain transition time (approx. 0.5 sec) is unavoidable.
Acceptable audio may have error rates up to a value of
700dec. Individual evaluation of this value by the con-
troller and an appropriate threshold may define the fall-
back mode from NICAM to FM/AM-Mono in case of
poor NICAM reception.
0
1
0
0
1
0
1
0
Data transmission only; no audio
Stereo sound (NICAMA/B), FM1
carries same channel
1
1
0
0
0
1
1
0
One mono signal (NICAMA). FM1
carries same channel as NICAMA
Two independent mono channels
(NICAMA, NICAMB). FM1 carries
same channel as NICAMA
The bit error rate per second (BER) can be calculated
by means of the following formula:
BER = ERROR_RATE * 12.3*10−6 /s
1
x
0
1
1
x
1
x
Data transmission only; no audio
Unimplemented sound coding
option (not yet defined by EBU
NICAM 728 specification)
AUTO_FM: monitor bit for the AUTO_FM Status:
0: NICAM source is NICAM
1: NICAM source is FM
Note: It is not necessary to read out and evaluate the
C_AD_BITS. All evaluation is performed in the MSP
and indicated in the STATUS register.
78
Micronas
MICRONAS [ MICRONAS ]
