Motorola DSP56012 Manuale Utente
2-16
DSP56012 User’s Manual
MOTOROLA
Signal Descriptions
Serial Audio Interface (SAI)
2.8
SERIAL AUDIO INTERFACE (SAI)
The SAI is composed of separate receiver and transmitter sections.
2.8.1
SAI Receive Section
The receive section of the SAI has four dedicated signals
.
Table 2-8
Serial Audio Interface (SAI) Receive Signals
Signal
Name
Signal
Type
State
during
Reset
Signal Description
SDI0
Input
Tri-stated
Serial Data Input 0
—This is the receiver 0 serial data input.
This signal is high impedance during hardware or software
reset, while receiver 0 is disabled (R0EN = 0), or while the chip
is in the Stop state. No external pull-up resistor is required.
reset, while receiver 0 is disabled (R0EN = 0), or while the chip
is in the Stop state. No external pull-up resistor is required.
SDI1
Input
Tri-stated
Serial Data Input 1
—This is the receiver 1 serial data input.
This signal is high impedance during hardware or software
reset, while receiver 1 is disabled (R1EN = 0), or while the chip
is in the Stop state. No external pull-up resistor is required.
reset, while receiver 1 is disabled (R1EN = 0), or while the chip
is in the Stop state. No external pull-up resistor is required.
SCKR
Input or
Output
Output
Tri-stated
Receive Serial Clock
—SCKR is an output if the receiver
section is programmed as a master, and a Schmitt-trigger
input if programmed as a slave.
input if programmed as a slave.
SCKR is high impedance if all receivers are disabled (personal
reset) and during hardware or software reset, or while the chip
is in the Stop state. No external pull-up is necessary.
reset) and during hardware or software reset, or while the chip
is in the Stop state. No external pull-up is necessary.
WSR
Input or
Output
Output
Tri-stated
Receive Word Select
—WSR is an output if the receiver section
is programmed as a master, and a Schmitt-trigger input if
programmed as a slave. WSR is used to synchronize the data
word and to select the left/right portion of the data sample.
programmed as a slave. WSR is used to synchronize the data
word and to select the left/right portion of the data sample.
WSR is high impedance if all receivers are disabled (personal
reset), during hardware reset, during software reset, or while
the chip is in the stop state. No external pull-up is necessary.
reset), during hardware reset, during software reset, or while
the chip is in the stop state. No external pull-up is necessary.