alc880 Realtek Semiconductor Corporation, alc880 Datasheet - Page 19

• Manufacturer Part Number: alc880
• Description: 7.1 Channel High Definition Audio Codec
• Manufacturer: Realtek Semiconductor Corporation

7.1.2.
The HDA controller supports two SDOs for the outbound stream, up to 15 SDIs for the inbound stream.
RST#, BCLK, SYNC, SDO0 and SDO1 are driven by the controller to codecs. Each codec drives its own
point-to-point SDI signal(s) to the controller.
Figure 6, on page 10, shows the possible connections between the HDA controller and codecs:
• Codec 0 is a basic connection. There is one single SDO and one single SDI for normal transmission
• Codec 1 has two SDOs for doubled outbound rate, and a single SDI for normal inbound rate
• Codec 3 supports a single SDO for normal outbound rate, and two SDIs for doubled inbound rate
• Codec N has two SDOs and multiple SDIs
The multiple SDOs and multiple SDIs are used to expand the transmission rate between controller and
codecs. Section 7.2 Frame Composition, page 10, describes the detailed outbound and inbound stream
compositions for single and multiple SDOs/SDIs.
The connections shown in Figure 6 can be implemented concurrently in an HDA system. The
ALC880(D) is designed to receive a single SDO stream.
7.1 Channel High Definition Audio Codec
Signal Name
BCLK
SYNC
RST#
SDO
SDI
BCLK
SYNC
SDO
SDI
Signaling Topology
Codec/Controller
Controller
Controller
Controller
Controller
Source
Controller samples SDI at rising edge of BCLK
Type for Controller Description
Input/Output
Codec samples SDO at both rising and falling edge of BCLK
Table 6.
Output
Output
Output
Output
8-Bit Frame SYNC
7
3
6
Figure 5.
5
2
4
HDA Signal Definitions
3
1
2
Global 24.0MHz bit clock.
Global 48kHz Frame Sync and outbound tag signal.
Serial data output from controller.
Serial data input from codec. Weakly pulled down by the
controller.
Global active low reset signal.
1
9
0
Bit Timing
0
999 998 997 996 995 994 993 992 991 990
499
Start of Frame
498
497
496
Track ID: JATR-1076-21
495
494
ALC880 Series
Datasheet
Rev. 1.4