alc260d-ve-lf Realtek Semiconductor Corporation, alc260d-ve-lf Datasheet - Page 20

• Manufacturer Part Number: alc260d-ve-lf
• Description: 2 Channel High Definition Audio Codec
• Manufacturer: Realtek Semiconductor Corporation

7.2.3.
The HDA link is designed for sample rates of 48kHz. Variable sample rates are delivered in multiple or
sub-multiple rates of 48kHz. Two sample blocks per frame result in a 96kHz delivery rate. One sample
block over two frames results in a 24kHz delivery rate. The HDA specification states that the sample rate of
the outbound stream be synchronized by the controller, not by the codec. Each stream has its own sample
rate, independent of any other stream.
The HDA controller supports 48kHz and 44.1kHz base rates. Table 7 shows the recommended sample rates
based on multiples or sub-multiples of one of the two base rates.
Rates in sub-multiples (1/n) of 48kHz are interleaving n frames containing no sample blocks. Rates in
multiples (n) of 48kHz contain n sample blocks in a frame. Table 8 shows the delivery cadence of variable
rates based on 48kHz.
The HDA link is defined to operate at a fixed 48kHz frame rate. To deliver samples in (sub) multiple rates
of 44.1kHz, an appropriate ratio between 44.1kHz and 48kHz must be maintained to avoid frequency drift.
The appropriate ratio between 44.1kHz and 48kHz is 147/160. Meaning 147 sample blocks are transmitted
every 160 frames.
The cadence ‘12-11-11-12-11-11-12-11-11-12-11-11-11- (repeat)’, interleaves 13 frames containing no
sample blocks in every 160 frames. It provides a low long-term frequency drift for 44.1kHz of delivery rate.
Rates in sub-multiples (1/n) of 44.1kHz also follow this cadence AND interleave n empty frames. Rates in
multiples (n) of 44.1kHz applying this cadence contain n sample blocks in the non-empty frame AND
interleave an empty frame between non-empty frames (Table 9, page 14).
2 Channel High Definition Audio Codec
N: No sample block in a frame
(Sub) Multiple
192kHz
12kHz
16kHz
32kHz
48kHz
96kHz
8kHz
Rate
1/6
1/4
1/3
1/2
2/3
Y: One sample block in a frame
Y
1
2
4
x
: X sample blocks in a frame
Variable Sample Rates
48kHz Base
8kHz (1 sample block every 6 frames)
12kHz (1 sample block every 4 frames)
16kHz (1 sample block every 3 frames)
24kHz (1 sample block every 2 frames)
32kHz (2 sample blocks every 3 frames)
48kHz (1 sample block per frame)
96kHz (2 sample blocks per frame)
192kHz (4 sample blocks per frame)
Delivery Cadence
YNNNNN (repeat)
YNNN (repeat)
YNN (repeat)
Y
Y (repeat)
Y
Y
2
2
4
NN (repeat)
(repeat)
(repeat)
Table 7. Defined Sample Rate and Transmission Rate
Table 8. 48kHz Variable Rate of Delivery Timing
13
44.1kHz Base
Description
One sample block is transmitted every 6 frames
One sample block is transmitted every 4 frames
One sample block is transmitted every 3 frames
One sample block is transmitted every 6 frames
Two sample blocks are transmitted in each frame
Four sample blocks are transmitted in each frame
11.025kHz (1 sample block every 4 frames)
22.05kHz (1 sample block every 2 frames)
44.1kHz (1 sample block per frame)
88.2kHz (2 sample blocks per frame)
176.4kHz (4 sample blocks per frame)
One sample block is transmitted every 6 frames
Track ID: JATR-1076-21 Rev. 1.4
ALC260(D)
Datasheet