Cirrus Logic CS4970x4 - Manual (Page 100)

CS4953x4/CS4970x4 DSP Manager API Description
CS4953x4/CS4970x4 System Designer’s Guide
DS810UM6 Copyright 2013 Cirrus Logic, Inc 7-7
AND Command = 0xEF80HHHH 0xhhhhhhhh
Read Request Command = 0xEFCnHHHH
Read Response Message = 0x6FC0HHHH 0xhhhhhhhh
n = number of words – 1 (bits [20..16])
0xHHHH = Index
0xhhhhhhhh = Data Value
7.4.2 DSP_CFG_xxx Registers
The DSP_CFG_xxx registers in Table 7-4 are used to specify the desired firmware configuration. The
writeable parameters are deliberately defined in contiguous locations so that they can be written from the
microcontroller to the DSP as efficiently as possible.
Table 7-3. Microcontroller Interface API
Index Variable Description
0x0000 DSP_BOOT
Bit 9 = Reserved
Whenever a non-zero value is written to this register, the DSP manager firmware begins the
specified configuration change. When the change is complete, this register value is reset to
zero. The DSP manager may also (optionally) send an unsolicited message to the
microcontroller upon completion of the operation.
Bit 8 = configuration lock bit. If this bit is set, the DSP firmware assumes that the
DSP_CFG_* variables are being modified by the microcontroller
Bits 7: 0 = boot action
0x00 = system is not in any of the following states.
0x01 = change to new configuration, as defined in DSP_CFG_xxx variables below
0x02 = save state in preparation for power down
0x08 = shut down
0x04 = save calibration parameters to DSP state flash area
Table 7-4. DSP_CFG_xxx Firmware Configuration Registers
Index Variable Description
0x0001 DSP_CFG_INPUT_FS
Input source sample rate, determined by DSP
Note: In case of PCM input, DSP_CFG_INPUT_FS is sent out as an unsolicited
message along wtih the PCM autodetect message (format = EF0000001
0000000X = Input sample rate. Refer to Sample Rate table in the
DSP_CFG_OUTPUT_FS variable.
This message can be disabled using bit 2 in DSP_MSG_MASK in
Table 7-5 .
0x0002 DSP_CFG_STREAM_TYPE
Input source stream type, determined by DSP
Note: Refer to
Table 7-1 for stream types
0x0003 DSP_CFG_INPUT_CHANNELS
Read Only
Value in this index determines the channels present in the input PCM stream over
HDMI.
Bits[7:0]=LFE ,Rb, Lb , Rs , Ls, R , C, L. Other bits RSVD.
Not valid for SPDIF input source.
Default:0xffffffff
DSP_CFG_STREAM_FS Input stream sample rate, as determined by DSP