XMOS xCORE-200 Multi-channel Audio board, Design Manual

Page: 110 / 112

USB Audio Design Guide 110/110
Function adatReceiver48000
Description ADAT Receive Thread (48kHz sample rate).
When a data rame is received, samples will be output onto the streaming
channel At first a word 0x000000Z1 will be output, where
Z
are the user data;
after that eight words 0x0ZZZZZZ0 will be output where
ZZZZZZ
is a 24-bit
sample value. The eight words may refer to sample values on eight channels,
or on fewer channels if muxing is used.
The function will return if it cannot lock onto a 48,000 Hz signal. Normally the
48000 function is called in a while(1) loop. If both 44,100 and 48,000 need to
be supported, they should be called in sequence in a while(1) loop. Note that
the functions are large, and that 44,100 should not be called if 44.1 KHz does
not need to be supported.
Type
void
adatReceiver48000(buffered in port:32 p, chanend oChan)
Parameters
p
ADAT port - should be 1-bit and clocked at 100MHz
oChan
channel on which decoded samples are output
Function adatReceiver44100
Description ADAT Receive Thread (44.1kHz sample rate).
When a data rame is received, samples will be output onto the streaming
channel At first a word 0x000000Z1 will be output, where
Z
are the user data;
after that eight words 0x0ZZZZZZ0 will be output where
ZZZZZZ
is a 24-bit
sample value. The eight words may refer to sample values on eight channels,
or on fewer channels if muxing is used.
The function will return if it cannot lock onto a 44,100 Hz signal. Normally the
44,100 function is called in a while(1) loop. If both 44,100 and 48,000 need to
be supported, they should be called in sequence in a while(1) loop. Note that
the functions are large, and that 48,000 should not be called if 48 Khz does
not need to be supported.
Type
void
adatReceiver44100(buffered in port:32 p, chanend oChan)
Parameters
p
ADAT port - should be 1-bit and clocked at 100MHz
oChan
channel on which decoded samples are output
XM0088546.1