CDB42528 Cirrus Logic Inc, CDB42528 Datasheet - Page 50

• Manufacturer Part Number: CDB42528
• Description: BOARD EVAL FOR CS42528/CS49300
• Manufacturer: Cirrus Logic Inc

Specifications of CDB42528

• Main Purpose: Audio, Audio Processing
• Embedded: Yes, DSP
• Utilized Ic / Part: CS49300, CS42528
• Primary Attributes: 8 Single-Ended Analog Inputs and Outputs, 4 S/PDIF Inputs and 2 S/PDIF Outputs
• Secondary Attributes: Parallel, RS422, RS232, UDSP Interfaces
• Product: Audio Modules
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant
• Other names: 598-1503

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Figure 29. Typical Parallel Host Mode Control
READ_BYTE_*(HOST MESSAGE REGISTER)
READ_BYTE_*(HOST CONTROL REGISTER)
READ_BYTE_*(HOST CONTROL REGISTER)
YES
Read Sequence Flow Diagram
HOUTRDY==1
MORE BYTES
HOUTRDY==1
WAIT 100 uS
TO READ?
INTREQ = 0
FINISHED
NO
YES
YES
NO
YES
NO
3) In order to determine whether the CS493XX
4) The host knows that the DSP is ready to
5) If the host expects to read any more response
6) After the response has been read the host
the communication interface. Please note that
‘Read_Byte_*()’ is a generalized reference to
either Read_Byte_MOT() or Read_Byte_INT().
has an outgoing control byte that is valid, the
host must check the HOUTRDY bit of the Host
Control Register (bit 1). If HOUTRDY is high,
then the Host Message Register contains a
valid message byte for the host. If HOUTRDY
is low, then the DSP has not placed a new
control byte in the Host Message Register, and
the host should poll the Host Control Register
again.
provide a new response byte at this point. The
host can safely read a byte from the Host
Message Register (A[1:0] = 00b).
bytes, the host should once again check the
HOUTRDY bit (return to step 1). Please refer to
one of the application code user’s guides to
determine the length of messages to read from
the CS493XX. Typically this length is 1, 3 or 6
bytes, and can be deduced from the message
OPCODE.
should wait at least 100 uS and check
HOUTRDY one final time. If HOUTRDY is high
once again this means that an unsolicited
message has come during the read process
and the host has another message to read (i.e.
skip back to step 4 and read out the new
message).
CS49300 Family DSP
DS339F7