T7507 Quad PCM Codec with Filters,
Termination Impedance, and Hybrid Balance
Data Sheet
August 1999
Functional Description (continued)
Input Word Definition
The control data input on DI is an 8-bit word of the format:
C1 C0 M D4 D3 D2 D1 D0
Bits C0 and C1 are the channel select bits. Bit M is a mode control bit. Bits D0, D1, D2, and D3 are data bits. Bit D4
can be either a mode control bit or a data bit. If M is set to 0, the data word is set to the PCM time-slot assignment
mode and bit D4 is a data bit. If M is set to 1, then D4 is also a mode set bit. If M, D4 = 1, 0, then the data word rep-
resents the relay/switch control delayed/nondelayed timing mode. If M, D4 = 1, 1 then the data word represents the
codec/SLIC control mode.
Table 3. C0, C1 Channel Select
C1
C0
Channel
0
0
1
1
0
1
0
1
0
1
2
3
Table 4. M, D4, D3, D2, D1, D0 Mode Select and Data
M
D4
D3
D2
D1
D0
0
Time-Slot
Time-Slot
Time-Slot
Time-Slot
Time-Slot
Assignment
Assignment
Assignment
Assignment
Assignment
1
1
0
Delayed/Nondelayed
Relay State
Relay State
Relay State
PCM Timing Mode or Control Information Control Information Control Information 1
Reserved*
3
2
1
T7507 Per Channel
Powerup/Powerdown
Channel Receive
Gain
B1 SLIC Control Bit
B0 SLIC Control Bit
* Delayed/nondelayed PCM timing is a global parameter—all channels are programmed to the most recent value. To program PCM timing, use
C0 = C1 = 0. (That is channel 0.) M = 1, D4 = 0. When programming C1, C0 = 01, M = 1, D4 = 0, then D3 must be programmed to 0. When C1,
C0 = 10, 11, M = 1, D4 = 0, then D3 is ignored.
Table 5. M = 0 Mode (PCM Time-Slot Assignment)
D4
D3
D2
D1
D0
Function
0
0
0
0
0
0
0
0
0
1
Time Slot 0
Time Slot 1
.
.
.
1
1
1
1
1
Time Slot 31
Note: Do not assign two channels to the same time slot. If two channels are assigned to the same time slot, the result is indeterminate. It is rec-
ommended that time-slot assignment should only be done when the channel is powered down. If multiple chips are tied to the same DX
bus, this can result in bus contention. Thus, reassignment of time slots should be done before the channel is powered up. For all codecs,
upon powerup, channel 0 will be assigned to time slot 0, channel 1 will be assigned to time slot 1, channel 2 will be assigned to time slot
2, and channel 3 will be assigned to time slot 3.
12
Lucent Technologies Inc.
AGERE [ AGERE SYSTEMS ]
