Cirrus Logic CS4970x4 - Manual (Page 106)

Legacy API Still in Use
CS4953x4/CS4970x4 System Designer’s Guide
DS810UM6 Copyright 2013 Cirrus Logic, Inc 7-13
7.5 Legacy API Still in Use
There are many common functions for which the legacy APIs should definitely be used, although the new
DSP manager firmware makes the use of those APIs easier. For example, the legacy Audio Manager
module contains the registers described in
Table 7-6 , which should still be controlled through the legacy
API:
7.5.1 Legacy Audio Manager
Write Command = 0x830nHHHH 0xhhhhhhhh
Read Request Command = 0x83CnHHHH
Read Response Message = 0x03C0HHHH 0xhhhhhhhh
n = number of words – 1 (bits [20..16])
0xHHHH = Index
0xhhhhhhhh = Data Value
0x00021 DSP_AUTODETECT_MSG
Read Only
Refer to Section 7.3.7 for more information.
There are times when the DSP needs to inform the host of certain changes during
its operation. For example, the DSP sending a message to the host indicating that
the input stream has changed from Dolby Digital to DTS. This information is
useful to the host so it can update the Front panel of the Unit. This type of
message is an unsolicited message because it was initiated by the DSP rather
than the host.
Changes that are reported to the host are:
1. Changes in the input stream type reported by DSP_AUTODETECT_MSG
2. Changes in the incoming bitstream reported by DSP_LAST_ACCN_MSG
0x00022 DSP_LAST_ACCN_MSG
Read Only
Refer to Section 7.3.8 for more information
0x00023 DSP_FLASH_MCU_SCRATCHPAD
Read Only
Address in flash of the beginning of the microcontroller scratch pad area
0x00024 DSP_MSG_MASK
Bits to configure what classes of unsolicited messages the DSP should generate
Bit 0 = 0/1 Disables/enables Flash Image Verification message
Bit 1 = 0/1Disable/enables unsolicited autodetect messages.
Bit 2 = 0/1 Disable/Enable unsolicited Fs message for PCM Input.
0x00025 DSP_FLASH_IMAGE_ADDRESS
Determines the address in the serial Flash where the writable Flash image
begins.
Table 7-5. Firmware Status Registers (Continued)
Index Variable Description