ADSP-BF537 Blackfin Processor Hardware Reference
12-51
SPORT Controllers
instruction; the
SLEN
field tells the SPORT how many of those bits
to shift out of the register over the serial link. The SPORT always
transfers the
SLEN+1
lower bits from the transmit buffer.
L
The frame sync signal is controlled by the
SPORTx_TFSDIV
and
SPORTx_RFSDIV
registers, not by
SLEN
. To produce a frame sync
pulse on each byte or word transmitted, the proper frame sync
divider must be programmed into the frame sync divider register;
setting
SLEN
to 7 does not produce a frame sync pulse on each byte
transmitted.
•
Internal transmit frame sync select
. (
ITFS
). This bit selects
whether the SPORT uses an internal
TFS
(if set) or an external
TFS
(if cleared).
•
Transmit frame sync required select
. (
TFSR
). This bit selects
whether the SPORT requires (if set) or does not require (if cleared)
a transmit frame sync for every data word.
L
The
TFSR
bit is normally set during SPORT configuration. A frame
sync pulse is used to mark the beginning of each word or data
packet, and most systems need a frame sync to function properly.
•
Data-Independent transmit frame sync select
. (
DITFS
). This bit
selects whether the SPORT generates a data-independent
TFS
(sync
at selected interval) or a data-dependent
TFS
(sync when data is
present in
SPORTx_TX
) for the case of internal frame sync select
(
ITFS = 1
). The
DITFS
bit is ignored when external frame syncs are
selected.
The frame sync pulse marks the beginning of the data word. If
DITFS
is set, the frame sync pulse is issued on time, whether the
SPORTx_TX
register has been loaded or not; if
DITFS
is cleared, the
frame sync pulse is only generated if the
SPORTx_TX
data register has
been loaded. If the receiver demands regular frame sync pulses,
DITFS
should be set, and the processor should keep loading the
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 ...