T E C H NI CA L INFO RMA T IO N
12
The complete slave address is:
10000
A1
A0
MSB
LSB
Register Assignments
The registers in the TA2021-100 are selected by the eight-bit index register. At power-up the
Index register is set to zero. The seven least-significant bits of the Index register define the
register address space in the TA2021-100. When a 1 is written to the MSB of the Index register
the Index register value is auto-incremented (by 1) after each byte transfer is complete. If a 0 is
written to the MSB of the Index register the Index register value is not changed.
The following table indicates the Index register address of each register:
I6
I5
I4
I3
I2
I1
I0
Register Addressed
0000000
STATUS
0000001
FAULT
0000010
INITIAL STATE
0000011
VOLUME ADC
0000100
CONTROL
0000101
CONFIGURATION
0000110
VOLUME1 (Channel 1)
0000111
VOLUME2 (Channel 2)
00010
X
X
Test
XXX
1
1
XX
Reserved
X = Don’t care
All Test Registers/Bits should NOT be accessed as they are used for manufacturing test of the
TA2021-100 and can cause unexpected operation. All Reserved Registers/Bits are read-only with
a value of 0.
STATUS Register
ST7
ST6
ST5
ST4
ST3
ST2
ST1
ST0
Overload
Detect
Over-
current
Detect
Reserved
Reserved
Reserved
Mute In
Silence
Muted
Fault
ST7:
Overload detect. When 0, indicates normal operation. When 1, indicates that
the level of the audio input signal has overloaded the amplifier and that the
audio signal is starting to distort. This bit is read/write. Writing a 0 to it will
clear it.
ST6:
Over-current detect. When 0, indicates normal operation. When 1, indicates
that the voltage across R
S
has become greater than V
OC-LIMIT, indicating an over-
current condition and the TA2021-100 is attempting to limit the current by
decreasing the input level using the volume control. This bit is read/write.
Writing a 0 to it will clear it.