IDT821068 Ver la hoja de datos (PDF) - Integrated Device Technology
Número de pieza
componentes Descripción
Lista de partido
IDT821068 Datasheet PDF : 45 Pages
| |||
IDT821068 OCTAL PROGRAMMABLE PCM CODEC
INDUSTRIAL TEMPERATURE RANGE
Linear GCI Structure
In GCI linear mode, one GCI frame consists of 8 GCI time slots,
each GCI time slot consists of four 8-bit bytes. Four of the 8 time slots
are used as Monitor Channel and C/I octet, they have a common data
structure:
- Two Don’t Care bytes.
- One monitor channel byte, which is used for reading/writing control
data/coefficients from/to the device for channel A and B.
- One C/I byte, which contains a 6 bit width C/I channel sub-byte
together with an MX bit and an MR bit. All real time signaling
information is carried on the C/I channel sub-byte. The MX (Monitor
Transmit) bit and MR (Monitor Receive) bits are used for handshaking
functions for channel A and B. Both MX and MR bits are active low.
Other four GCI time slots are used for linear voice data (16-bit 2’s
complement). Each time slot consists of two 16-bit linear voice data
bytes: one byte contains the linear voice data for channel A, the other
byte contains the linear voice data for channel B.
The GCI time slot assignment is determined by the TS pin. When
TS is low, the linear GCI Frame Structure is shown in Figure 5.
In linear operation, total eight GCI time slots are required to access
the eight channels of IDT821068. See Table 2 for detailed information
about time slot assignment for linear mode.
FSC
DCL
DD
DU
Detail A
DD
DU
125 µs
TS0 TS1 TS2 TS3 TS4 TS5 TS6 TS7
Detail A
Detail B
TS0 TS1 TS2 TS3 TS4 TS5 TS6 TS7
TS0-3 for Monitor and C/I
Don't Care
Don't Care
TS4-7 for Linear Voice
Data
Monitor Channel C/I Channel
MM
RX
Don't Care
Don't Care
Monitor Channel C/I Channel
MM
RX
Detail B
DD
DU
16-bit Linear Voice Data for Channel A
16-bit Linear Voice Data for Channel B
16-bit Linear Voice Data for Channel A
16-bit Linear Voice Data for Channel B
Figure 5. Linear GCI Frame Structure When TS Is Low
Table 2 - Time Slot Selection for linear GCI
IDT821068
Channels
1
2
3
4
5
6
7
8
Timeslot
Timeslot0
Timeslot0
Timeslot1
Timeslot1
Timeslot2
Timeslot2
Timeslot3
Timeslot3
1
Timeslot4
2
Timeslot4
3
Timeslot5
4
Timeslot5
5
Timeslot6
6
Timeslot6
7
Timeslot7
8
Timeslot7
TS = 0
Monitor and C/I
A
B
A
B
A
B
A
B
TS = 1
A
B
A
B
A
B
A
B
Timeslot
Timeslot4
Timeslot4
Timeslot5
Timeslot5
Timeslot6
Timeslot6
Timeslot7
Timeslot7
Timeslot0
Timeslot0
Timeslot1
Timeslot1
Timeslot2
Timeslot2
Timeslot3
Timeslot3
Voice Channel
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B
8
Share Link: 