Signal/Connection Descriptions
General Purpose Input/Output (GPIO)
GENERAL PURPOSE INPUT/OUTPUT (GPIO)
Table 1-10 General Purpose I/O (GPIO) Signals
Signal |
Signal Type |
State during |
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Signal Description |
Name |
Reset |
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GPIO0– |
Input or |
Disconnected |
General Purpose Input/Output—These signals |
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GPIO7 |
Output |
internally |
are used for control and handshake functions |
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(standard or |
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between the DSP and external circuitry. Each |
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open-drain) |
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GPIO signal may be individually programmed to |
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be one of four states: |
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• |
Not connected |
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• |
Input |
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• |
Standard output |
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• Open-drain output |
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DIGITAL AUDIO INTERFACE (DAX)
Table 1-11 Digital Audio Interface (DAX) Signals
Signal Name |
Type |
State During |
Signal Description |
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Reset |
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ADO |
Output |
Output, driven |
Digital Audio Data Output—This signal is an |
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high |
audio and non-audio output in the form of AES/ |
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EBU, CP340 and IEC958 data in a biphase mark |
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format. The signal is driven high when the DAX is |
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disabled, and during hardware or software reset. |
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ACI |
Input |
Tri-stated |
Audio Clock Input—This is the DAX clock input. |
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When programmed to use an external clock, this |
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input supplies the DAX clock. The external clock |
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frequency must 256, 384, or 512 times the audio |
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sampling frequency (256 x Fs, 384 x Fs or 512 x Fs, |
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respectively). The ACI signal is high impedance |
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(tri-stated) only during hardware or software reset. |
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If the DAX is not used, connect the ACI signal to |
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ground through an external pull-down resistor to |
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ensure a stable logic level at the input. |
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1-16 |
DSP56011/D |
MOTOROLA |