cxd2548r Sony Electronics, cxd2548r Datasheet - Page 71

• Manufacturer Part Number: cxd2548r
• Description: Cd Digital Signal Processor With Built-in Digital Servo And Dac
• Manufacturer: Sony Electronics

3-10. 1-bit DAC Block
(a) DAC block input timing
(b) Description of DAC block functions
Timing Chart 3-3 shows the DAC block input timing chart.
Audio data is not transferred from the CD signal processor block to the DAC block inside the CXD2548R.
This is to allow data to be sent to the DAC block via the audio DSP, etc.
When the data is input to the DAC block without using the audio DSP, the data must be connected outside
the LSI. In this case, EMPH, LRCK, BCK and PCMD can be connected directly with EMPHI, LRCKI, BCKI
and PCMDI.
Zero data detection
When the condition where the lower 4 bits of the input data are DC and the remaining upper bits are all "0"
or all "1" has continued about for 300ms, zero data is detected. Zero data detection is performed
independently for the left and right channels.
Mute flag output
The LMUT and RMUT pins go active when any one of the following conditions is met.
The polarity can be selected with the ZDPL command of $9X.
Attenuation operation
Assuming attenuation data X1, X2 and X3 (X1 > X3 > X2), the corresponding audio outputs are Y1, Y2 and
Y3 (Y1 > Y3 > Y2). First, X1 is sent, followed by X2. If X2 is sent before X1 reaches Y1 (A in the figure), X1
continues approaching Y2. Next, if X3 is sent before X1 reaches Y2 (B or C in the figure), X1 then
approaches Y3 from the value (B or C in the figure) at that point.
Soft mute
When any one of the following conditions is met, soft mute results and the input data is attenuated to "0".
• When zero data is detected
• When a high signal is input to the SYSM pin
• When the SMUT command of $AX is set
• When attenuation data of 000 (high) is set
• When "Soft mute" in the operation controls for serial control is high
• When a high signal (= mute) is input to the input pin SYSM
0dB
–
3FF (H)
0dB
23.2 [ms]
– 71 –
23.2 [ms]
A
Y1
B
Y3
C
Y2
23.2 [ms]
–
000 (H)
t
CXD2548R