Description of Operation
12-20
ADSP-BF537 Blackfin Processor Hardware Reference
The
TFS
signal is used as a transmit data valid signal which is active during
transmission of an enabled word. The SPORT’s data transmit pin is
three-stated when the time slot is not active, and the
TFS
signal serves as an
output-enabled signal for the data transmit pin. The SPORT drives
TFS
in
multichannel mode whether or not
ITFS
is cleared. The
TFS
pin in multi-
channel mode still obeys the
LTFS
bit. If
LTFS
is set, the transmit data valid
signal will be active low—a low signal on the
TFS
pin indicates an active
channel.
Once the initial
RFS
is received, and a frame transfer has started, all other
RFS
signals are ignored by the SPORT until the complete frame has been
transferred.
If
MFD > 0
, the
RFS
may occur during the last channels of a previous frame.
This is acceptable, and the frame sync is not ignored as long as the delayed
channel 0 starting point falls outside the complete frame.
In multichannel mode, the
RFS
signal is used for the block or frame start
reference, after which the word transfers are performed continuously with
no further
RFS
signals required. Therefore, internally generated frame
syncs are always data independent.
The Multichannel Frame
A multichannel frame contains more than one channel, as specified by the
window size and window offset. A complete multichannel frame consists
of 1 – 1024 channels, starting with channel 0. The particular channels of
the multichannel frame that are selected for the SPORT are a combination
of the window offset, the window size, and the multichannel select regis-
ters. See
.
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...