Datasheet

PCMCONF
Address: 0x55
Type: R/W
Software Reset: 0x21
Hardware Reset: 0x21
MSB LSB
b7 b6 b5 b4 b3 b2 b1 b0 Description
X ORD DIF INV FOR SCL PREC (1) PREC (1)
X 1 PCM order the LS bit is transmitted First
X 0 PCM order the MS bit is transmitted First
X 0 The word is right padded
X 1 The word is left padded
X 1 LRCKT Polarity compliant to I2S format
X 0 LRCKT Polarity inverted
X 0 I2S format
X 1 Different formats
X 1 Data are sent on the rising edge of SCKT
X 0 Data are sent on the falling edge of SCKT
X 0 0 16 bit mode (16 slots transmitted)
X 0 1 18 bit mode (18 slots transmitted)
X 1 0 20 bit mode (20 slots transmitted)
X 1 1 24 bit mode (24 slots transmitted)
PCMCONF is used to set the PCM Output Inter-
face configuration:
ORD: PCM order. If this bit is set to’1’, the LS Bit
is transmitted first, otherwise MS Bit is transmiited
first.
DIF: PCM_DIFF. It is used to select the position
of the valid data into the transmitted word. This
setting is significant only in 18/20/24 bit/word
mode.If it is set to ’0’ the word is right-padded,
otherwise it is left-padded.
INV (fig.13): It is used to select the LRCKT clock
polarity. If it is set to ’1’ the polarity is compliant to
I2S format (low -> left , high -> right), otherwise
the LRCKT is inverted. The default value is ’0’. (if
I2S have to be selected, must be set to ’1’ in the
STA013 configuration phase).
FOR: FORMAT is used to select the PCM Output
Interface format.
After hw and sw reset the value is set to 0 corre-
sponding to I
2
S format.
SCL (fig.14): used to select the Transmitter Serial
Clock polarity. If set to ’1’ the data are sent on the
rising edge of SCKT and sampled on the falling. If
set to ’0’ , the data are sent on the falling edge
and sampled on the rising. This last option is the
most commonly used by the commercial DACs.
The default configuration for this flag is ’0’.
PREC [1:0]: PCM PRECISION
It is used to select the PCM samples precision, as
follows:
’00’: 16 bit mode (16 slots transmitted)
’01’: 18 bit mode (32 slots transmitted)
’10’: 20 bit mode (32 slots transmitted)
’11’: 24 bit mode (32 slots transmitted)
The PCM samples precision in STA013 can be
16 or 18-20-24 bits.
When STA013 operates in 16 (18-20-24) bits
mode, the number of bits transmitted during a
LRCLT period is 32 (64).
LRCKT
LRCKT
INV_LRCLK=0
left
left
ri
g
ht
ri
g
ht
left
left INV_LRCLK=1
Figure 13.
LRCKT Polarity Selection
INV_SCLK=0
SCKT
SDO
Figure 14.
SCKT Polarity Selection
INV_SCLK=1
SCKT
SDO
STA013 - STA013B - STA013T
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