beautypg.com

9 general purpose input/output (gpio), Table210 general purpose i/o (gpio) signals, 10 digital audio interface (dax) – Motorola DSP56012 User Manual

Page 58: Table211 digital audio interface (dax) signals, General purpose input/output (gpio) -18, Digital audio interface (dax) -18, Table 2-10, General purpose i/o (gpio) signals -18, Table 2-11, Digital audio interface (dax) signals -18

background image

2-18

DSP56012 User’s Manual

MOTOROLA

Signal Descriptions

General Purpose Input/Output (GPIO)

2.9

GENERAL PURPOSE INPUT/OUTPUT (GPIO)

2.10

DIGITAL AUDIO INTERFACE (DAX)

Table 2-10

General Purpose I/O (GPIO) Signals

Signal

Name

Signal Type

State during

Reset

Signal Description

GPIO0–
GPIO7

Input or
Output
(standard or
open-drain)

Disconnected
internally

General Purpose Input/Output

—These signals

are used for control and handshake functions
between the DSP and external circuitry. Each
GPIO signal may be individually programmed to
be one of four states:

Not connected

Input

Standard output

Open-drain output

Table 2-11

Digital Audio Interface (DAX) Signals

Signal Name

Type

State During

Reset

Signal Description

ADO

Output

Output, driven
high

Digital Audio Data Output—

This signal is an

audio and non-audio output in the form of
AES/EBU, CP340 and IEC958 data in a biphase
mark format. The signal is driven high when the
DAX is disabled, and during hardware or software
reset.

ACI

Input

Tri-stated

Audio Clock Input—

This is the DAX clock input.

When programmed to use an external clock, this
input supplies the DAX clock. The external clock
frequency must 256, 384, or 512 times the audio
sampling frequency (256 x Fs, 384 x Fs or 512 x Fs,
respectively). The ACI signal is high impedance
(tri-stated) only during hardware or software reset.
If the DAX is not used, connect the ACI signal to
ground through an external pull-down resistor to
ensure a stable logic level at the input.