ANALOG I/O (Continued)

Name

Pin

I / O

Functional Description

MIC1

21

I

Mono microphone input

Either MIC1 or MIC2 can be muxed to a programmable boost amplifier with selection by the

MS bit (bit D8) in the General Purpose register, 20h. The boost amplifier gain (0 dB or 20 dB)

is set by the 20dB bit (D6) in the Mic Volume register, 0Eh. Nominal input levels at the two

gain settings are 1 Vrms and 0.1 Vrms respectively. The amplifier output is selectable (Record

Select register, 1Ah) by either the right or left channels of the Record Select Mux for

conversion on either or both channels of the stereo ADCs. The amplifier output can also be

accessed at the stereo mixer MIX1 (muting and mixing adjustments via Mic Volume register,

0Eh) where it is mixed equally into both left and right channels of Stereo Mix 3D for access to

the stereo outputs Line Out and Line Level Out. Access to the Mono analog output is

selected by a mux controlled by the MIX bit (D9) in General Purpose register, 20h.

MIC2

22

I

Mono microphone input

Either MIC1 or MIC2 can be muxed to a programmable boost amplifier with selection by the

MS bit (bit D8) in the General Purpose register, 20h. The boost amplifier gain (0 dB or 20 dB)

is set by the 20dB bit (D6) in the Mic Volume register, 0Eh. Nominal input levels at the two

gain settings are 1 Vrms and 0.1 Vrms respectively. The amplifier output is selectable (Record

Select register, 1Ah) by either the right or left channels of the Record Select Mux for

conversion on either or both channels of the stereo ADCs. The amplifier output can also be

accessed at the stereo mixer MIX1 (muting and mixing adjustments via Mic Volume register,

0Eh) where it is mixed equally into both left and right channels of Stereo Mix 3D for access to

the stereo outputs Line Out and Line Level Out. Access to the Mono analog output is

selected by a mux controlled by the MIX bit (D9) in General Purpose register, 20h.

LINE_IN_L

23

I

Left Stereo Channel Input

This line level input (1 Vrms nominal) is selectable at the left channel of the stereo Record

Select Mux for conversion by the left channel ADC. It can also be mixed into the left channel

of the Stereo Mix 3D signal at MIX1 under the control of the Line In Volume register, 10h. The

LINE_IN_L level can be muted (along with LINE_IN_R) or adjusted from +12 dB to -34.5 dB

in 1.5 dB steps. Stereo Mix 3D is combined into the Stereo Mix signal at MIX2 for access to

the stereo outputs Line Out and Line Level Out.

LINE_IN_R

24

I

Right Stereo Channel Input

This line level input (1 Vrms nominal) is selectable at the right channel of the stereo Input

Mux for conversion by the right channel ADC. It can also be mixed into the right channel of

the Stereo Mix 3D signal at MIX1 under the control of the Line In Volume register, 10h. The

LINE_IN_R level can be muted (along with LINE_IN_L) or adjusted from +12 dB to -34.5 dB

in 1.5 dB steps. Stereo Mix 3D is combined into the Stereo Mix signal at MIX2 for access to

the stereo outputs Line Out and Line Level Out.

LINE_OUT_L

35

O

Left Stereo Channel Output

This line level output (1 Vrms nominal) is fed from the left channel of the Stereo Mix signal

from MIX2 via the Master Volume register, 02h. The LINE_OUT_L amplitude can be muted

(along with LINE_OUT_R) or adjusted from 0 dB to -46.5 dB in 1.5 dB steps.

LINE_OUT_R

36

O

Right Stereo Channel Output

This line level output (1 Vrms nominal) is fed from the right channel of the Stereo Mix signal

from MIX2 via the Master Volume register, 02h. The LINE_OUT_R amplitude can be muted

(along with LINE_OUT_L) or adjusted from 0 dB to -46.5 dB in 1.5 dB steps.

MONO_OUT

37

O

Mono Output

This mono line level output (1 Vrms nominal) is fed from either a microphone input (MIC1 or

MIC2, after boost amplifier) or from the mono sum of the left and right Stereo Mix 3D

channels from MIX1. The optional National 3D Sound enhancement can be disabled (default)

by the 3D bit (bit D13) in the General Purpose register, 20h. Choice of input is by the MIX bit

(D9) in the same register. MIX=0 selects a microphone input. Output level can be muted or

adjusted from 0 dB to -46.5 dB in 1.5 dB steps via the Mono Volume register, 06h.

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