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

Signal Description

Name

Reset

GPIO0–

Input or

Disconnected

General Purpose Input/Output—These signals

GPIO7

Output

internally

are used for control and handshake functions

(standard or

between the DSP and external circuitry. Each

open-drain)

GPIO signal may be individually programmed to

be one of four states:

•

Not connected

•

Input

•

Standard output

• Open-drain output

DIGITAL AUDIO INTERFACE (DAX)

Table 1-11 Digital Audio Interface (DAX) Signals

Signal Name

Type

State During

Signal Description

Reset

ADO

Output

Output, driven

Digital Audio Data Output—This signal is an

high

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.

MOTOROLA

DSP56011 Technical Data Sheet, Rev. 1

1-17