ucb1200 NXP Semiconductors, ucb1200 Datasheet - Page 37

• Manufacturer Part Number: ucb1200
• Description: Advanced Modem/audio Analog Front-end
• Manufacturer: NXP Semiconductors

Philips Semiconductors
CODEC DATA TRANSFER INTO THE
Both the audio and the telecom data is transferred within the SIB frame (bit 11-0 and bit 47-32). This data is accompanied
by two data valid flags (bit 30: audio data valid, bit 31: telecom data valid). The codec data in the SIB frames is only
processed in the UCB1200 if the appropriate data valid flag is set in the frame; the data is discarded when the data flag
equals ‘0’. Figure 32 shows the basic codec data synchronization principle used in the UCB1200.
Figure 32 shows that audio and telecom data is made available for the codec up sample filters during the 64th bit in the
SIB frame. This implies that the codec data has to be transferred in one of the SIB frames preceding the codec sample
moment.
Note: If the programmed divisor equals a multiple of 4, the codec data transfer is synchronized to the SIB frame repetition
rate (e.g. AUD_DIV[n] = 8
frames, etc.).
1998 Jul 22
Advanced modem/audio analog front-end
SIBSYNC
SIBCLK
SIBDIN
1 sample is needed in 2 SIB frames, AUD_DIV[n] = 12
UCB1200
Fig.32 Codec input path data synchronization principle.
telecom data[n]
audio data[n]
audio_data_valid
telec_data_valid
SIB INTERFACE
bit64
&
&
37
DFF
DFF
UPSAMPLE FILTERS
fsa
fst
1 sample is needed in 3 SIB
input
latch
input
latch
Product specification
UCB1200