alc885-gr Realtek Semiconductor Corporation, alc885-gr Datasheet - Page 32
Manufacturer Part Number
7.1+2 Channel High-performance Hda Codec With Content Protection
Realtek Semiconductor Corporation
There are two types of response from the codec to the controller. Solicited Responses are returned by the
codec in response to a current command verb. The codec will send Solicited Response data in the next
frame, without regard to the Set (Write) or Get (Read) command. The 32-bit Response is interpreted by
software, opaque to the controller.
Unsolicited Responses are sent by the codec independently of software requests. Jack Detection or GPI
status information can be actively delivered to the controller and interpreted by software. The ‘Tag’ in
Bit[31:28] is used to identify unsolicited events. This tag is undefined in the HDA specifications.
Note: The response stream in the link protocol is 36-bits wide. The response is placed in the lower
7.5. Power Management
The ALC885 does not support Wake-Up events when in low power mode. All power management state
changes in widgets are driven by software. Table 16 shows the System Power State Definitions.
In the ALC885, all the widgets, including output/input converters, support power control. Software may
have various power states depending on system configuration.
Table 17 indicates those nodes that support power management. To simplify power control, software can
configure whole codec power states through the audio function (NID=01h). Output converters (DACs)
and input converters (ADCs) have no individual power control to supply fine-grained power control.
7.1+2 Channel High-Performance HDA Codec
With Content Protection
32-bit field. Bit-35 is a ‘Valid’ bit to indicate the response is ‘Ready’. Bit-34 is set to indicate that
an unsolicited response was sent.
All power on. Individual DACs and ADCs can be powered up or down as required
All amplifiers and converters (DACs and ADCs) are powered down. State maintained, analog reference
All amplifiers and converters (DACs and ADCs) are powered down. State maintained, but analog
reference is off (D1 + analog reference off)
Power still supplied. The codec stops the internal clock. State is maintained
All power removed. State lost
Table 16. System Power State Definitions
Table 15. Unsolicited Response Format
Table 14. Solicited Response Format