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31
IDT821054 QUAD PROGRAMMABLE PCM CODEC WITH MPI INTERFACE
INDUSTRIAL TEMPERATURE RANGE
3.4.3
LOCAL REGISTERS LIST
LREG1: Coefficient Selection, Read/Write (00H/80H)
The Coefficient Select bits (CS[7:0]) are used to control digital filters and function blocks on each channel. The digital filters include
Impedance Matching Filter, Echo Cancellation Filter, High-Pass Filter, Gain for Impedance Scaling, Gain in the Transmit/Receive Path
and Frequency Response Correction in the Transmit/Receive Path. See
Figure - 4 on page 11 for details. It should be noted that the
Impedance Matching Filter and Gain for Impedance Scaling are working together to adjust the impedance. So the CS[0] and CS[2] bits
should be set to the same value to ensure proper operation.
CS [7] = 0: The Digital Gain Filter in the Receive path (GRX) is disabled (default);
CS [7] = 1: The Digital Gain in the Receive path (GRX) is programmed by the Coe-RAM.
CS [6] = 0: The Frequency Response Correction filter in the Receive path (FRR) is disabled (default);
CS [6] = 1: The coefficient of the Frequency Response Correction filter in the Receive path (FRR) is programmed by the Coe-RAM.
CS [5] = 0: The Digital Gain Filter in the Transmit path (GTX) is disabled (default);
CS [5] = 1: The Digital Gain in the Transmit path (GTX) is set by the Coe-RAM.
CS [4] = 0: The Frequency Response Correction filter in the Transmit path (FRX) is disabled (default);
CS [4] = 1: The coefficient of the Frequency Response Correction filter in the Transmit path (FRX) is programmed by the Coe-RAM.
CS [3] = 0: The High-Pass Filter (HPF) is bypassed/disabled;
CS [3] = 1: The High-Pass Filter (HPF) is enabled (default).
CS [2] = 0: The Gain for Impedance Scaling filter (GIS) is disabled (default);
CS [2] = 1: The coefficient of the Gain for Impedance Scaling filter (GIS) is programmed by the Coe-RAM.
CS [1] = 0: The Echo Cancellation Filter (ECF) is disabled (default);
CS [1] = 1: The coefficient of the Echo Cancellation Filter (ECF) is programmed by the Coe-RAM.
CS [0] = 0: The Impedance Matching Filter (IMF) is disabled (default);
CS [0] = 1: The coefficient of theImpedance Matching Filter (IMF) is programmed by the Coe-RAM.
LREG2: Local Loopback Control and SLIC Input Interrupt Enable, Read/Write (01H/81H)
The SLIC Input Interrupt Enable bits IE[4:0] enable or disable the interrupt signal on each channel.
IE[4] = 0: Interrupt disabled. The interrupt generated by changes of SB3 (when SB3 is selected as an input) will be ignored (default);
IE[4] = 1: Interrupt enabled. The interrupt generated by changes of SB3 (when SB3 is selected as an input) will be recognized.
IE[3] = 0: Interrupt disabled. The interrupt generated by changes of SB2 (when SB2 is selected as an input) will be ignored (default);
IE[3] = 1: Interrupt enabled. The interrupt generated by changes of SB2 (when SB2 is selected as an input) will be recognized.
IE[2] = 0: Interrupt disabled. The interrupt generated by changes of SB1 (when SB1 is selected as an input) will be ignored (default);
IE[2] = 1: Interrupt enabled. The interrupt generated by changes of SB1 (when SB1 is selected as an input) will be recognized.
IE[1] = 0: Interrupt disabled. The interrupt generated by changes of SI2 will be ignored (default);
IE[1] = 1: Interrupt enabled. The interrupt generated by changes of SI2 will be recognized.
IE[0] = 0: Interrupt disabled. The interrupt generated by changes of SI1 will be ignored (default);
b7
b6
b5
b4
b3
b2
b1
b0
Command
R/W
0
0000
00
I/O data
CS[7]
CS[6]
CS[5]
CS[4]
CS[3]
CS[2]
CS[1]
CS[0]
b7
b6
b5
b4
b3
b2
b1
b0
Command
R/W
0
0000
01
I/O data
IE[4]
IE[3]
IE[2]
IE[1]
IE[0]
DLB_PCM
ALB_1BIT
DLB_1BIT