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
0
0
1
1
C0
0
1
0
1
Channel
0
1
2
3
Table 4. M, D4, D3, D2, D1, D0 Mode Select and Data
M
0
1
D4
Time-Slot
Assignment
0
D3
Time-Slot
Assignment
Delayed/Nondelayed
PCM Timing Mode or
Reserved*
T7507 Per Channel
Powerup/Powerdown
D2
Time-Slot
Assignment
Relay State
Control Information
3
Channel Receive
Gain
D1
Time-Slot
Assignment
Relay State
Control Information
2
B1 SLIC Control Bit
D0
Time-Slot
Assignment
Relay State
Control Information 1
B0 SLIC Control Bit
1
1
* 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
0
0
D3
0
0
D2
0
0
D1
0
0
D0
0
1
Function
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 D
X
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 ]
