am79q02 ETC-unknow, am79q02 Datasheet - Page 54

• Manufacturer Part Number: am79q02
• Description: Quad Subscriber Line Audio-processing Circuit Qslac Devices
• Manufacturer: ETC-unknow

50, 51. Write/Read IIR Z Filter Coefficients (IIR only)
54
(9A/9Bh)
R/W = 0: Write
R/W = 1: Read
This command writes/reads the IIR filter section only, without affecting the FIR.
The Z-transform equation for the Z filter is defined as:
Sample rate = 32 kHz
For i = 0 to 5 and 7
Power Up and Hardware Reset (
See note under Commands 31 and 32.
Note: Z
one. The input to the IIR filter section is first increased by a gain of 1/Z
avoiding truncation limitations through processing within this filter. The IIR filter output is then multiplied
by Z
coefficients, but it also includes the initial 1/Z
and normalization, is actually Z
Command
I/O Data Byte 11
I/O Data Byte 12
I/O Data Byte 13
I/O Data Byte 14
I/O Data Byte 15
6
to normalize the overall gain. Z
6
is used for IIR filter scaling only. Its value is typically greater than zero but less than or equal to
(H
H
z
z
i
6
z
z
z ( )
=
=
(z) = 0)
C1i 2
C16 2
=
z
•
0
•
Am79Q02/021/031 Data Sheet
+
–
z
–
m1i
1
m16
•
{
z
{
1
–
5
1
1
/Z
+
+
+
6
C2i 2
C45
C25
C26
C47
C27
.
C26 2
RST
z
D
1
2
5
7
•
is the actual IIR filter gain value defined by the programmed
•
z
) Values = 0190 0190 0190 0190 0190 0190 01 0190 (Hex)
•
2 –
–
m2i
–
+
6
m26
D
0
z
gain. The theoretical effective IIR gain, without the Z
[
6
3
1
}
•
+
z
C3i 2
–
3
m45
m25
m26
m47
m27
D
+
0
5
•
z
4
•
–
m3i
z
4 –
(
D
1
1
+
4
+
z
-------------------------------------- -
5
C4i 2
1 z
•
6
–
z
, improving dynamic range and
C35
C15
C16
C37
C17
D
6
•
1
•
3
7
z
–
•
7
m4i
z
•
1 –
)
z
]
–
D
}
0
1
2
MPI Command
m35
m15
m16
m37
m17
D
1
1
6
R/W
D
gain
0