UPC1857ACT datasheet(22/44 Pages) NEC

22 / 44 page

µµµµPC1857A

4.4.3 Surround mode

The following surround modes can be selected by using data of bits D3 and D2 of subaddress 00H.

Simulated :

Simulated stereo sound for monaural source. The difference between the signal that has gone

through HPF and the signal that has gone through LPF is calculated, and the phase of the

difference is shifted and added to the original signal. The simulated stereo effect is created if the

output frequency characteristics of the L-channel and R-channel signals is comb-shaped.

Music

Surround sound for stereo source. The phase of the differential signal between L and R channels

(L-R signal) is rotated by a phase shifter (1-unit), and is added to the original signal.

Movie

Surround sound for stereo source. The phase of the differential signal between L and R channels

(L-R signal) is rotated by a phase shifter (4-unit), and is added to the original signal.

OFF

Original signal as is.

Figure 4-3. Surround Mode

Subaddress

00H

Mute

Output selection

Mode

Data

Surround mode

Surround effect

Simulated

Music

Movie

OFF

Caution The surround mode is OFF (D3, D2 = 11) if the stereo mode is not selected by the output

selection bits (D5, D4 = 00).

UPC1857ACT 데이터시트(PDF) 22 Page - NEC