Motorola DSP56012 User Manual

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6-16
DSP56012 User’s Manual 
MOTOROLA
Serial Audio Interface
Serial Audio Interface Programming Model
6.3.2.13
RCS Receiver Left Data Full (RLDF)—Bit 14
Receiver Left Data Full (RLDF) is a read-only status bit that, together with RRDF (see 
below), indicates the status of the enabled receive data registers. RLDF is set when 
the left data word (as indicated by WSR pin and the RLRS bit in the RCS) is 
transferred to the receive data registers after it was shifted in via the shift register of 
the enabled receiver. Since audio data samples are composed of left and right data 
words that are read alternately, normal operation of the receivers occurs when either 
RLDF or RRDF is set, in a corresponding alternating sequence. A receive overrun 
condition is indicated when both RLDF and RRDF are set. RLDF is cleared when the 
DSP reads the receive data register of the enabled receiver, provided that 
 In case of a receive overrun condition, 
 
RLDF is cleared by first reading the RCS, followed by reading the receive data 
register of the enabled receivers. RLDF is also cleared by hardware and software 
reset, when the DSP is in the Stop state, and when all receivers are disabled (R0EN 
and R1EN cleared). If RXIE is set, an interrupt request will be issued when RLDF is 
set. The vector of the interrupt request will depend on the state of the receive overrun 
condition. The RLDF bit is cleared during hardware reset and software reset.
6.3.2.14
RCS Receiver Right Data Full (RRDF)—Bit 15
Receiver Right Data Full (RRDF) is a read-only status bit which, in conjunction with 
RLDF, indicates the status of the enabled receive data register. RRDF is set when the 
right data word (as indicated by the WSR pin and the RLRS bit in RCS) is transferred 
to the receive data registers after being shifted in via the shift register of the enabled 
receiver. Since audio data samples are composed of left and right data words that are 
read alternately, normal operation of the receivers occurs when either RLDF or RRDF 
is set, in a corresponding alternating sequence. A receive overrun condition is 
indicated when both RLDF and RRDF are set. RRDF is cleared when the DSP reads 
the receive data register of the enabled receiver, provided that 
 
In case of a receive overrun condition, 
 RRDF is cleared by first 
reading the RCS, followed by reading the receive data register of the enabled 
receiver. RRDF is also cleared by hardware reset and software reset, when the DSP is 
in the Stop state, and when all receivers are disabled (R0EN and R1EN cleared). If 
RXIE is set, an interrupt request will be issued when RRDF is set. The vector of the 
interrupt request will depend on the state of the receive overrun condition. The 
RRDF bit is cleared during hardware reset and software reset.
(RLDF
RRDF
1).
=
(RLDF
RRDF
1),
=
(RLDF
RRDF
1).
=
(RLDF
RRDF
1),
=