ADSP-BF537 Blackfin Processor Hardware Reference
12-35
SPORT Controllers
Early Versus Late Frame Syncs (Normal Versus
Alternate Timing)
Frame sync signals can occur during the first bit of each data word (late)
or during the serial clock cycle immediately preceding the first bit (early).
The
LATFS
and
LARFS
bits of the
SPORTx_TCR1
and
SPORTx_RCR1
registers
configure this option.
When
LATFS = 0
or
LARFS
=
0
, early frame syncs are configured; this is
the normal mode of operation. In this mode, the first bit of the transmit
data word is available and the first bit of the receive data word is sampled
in the serial clock cycle after the frame sync is asserted, and the frame sync
is not checked again until the entire word has been transmitted or
received. In multichannel operation, this corresponds to the case when
multichannel frame delay is 1.
If data transmission is continuous in early framing mode (in other words,
the last bit of each word is immediately followed by the first bit of the next
word), then the frame sync signal occurs during the last bit of each word.
Internally generated frame syncs are asserted for one clock cycle in early
framing mode. Continuous operation is restricted to word sizes of 4 or
longer (
SLEN
≥
3
).
Figure 12-11. Example of TCKFE = RCKFE = 1, Transmit and Receive
Connected
B1
B2
B3
TSCLK = RSCLK
INTERNAL OR EXTERNAL
TFS = RFS
INTERNAL OR EXTERNAL
DT
B0
B1
B2
B3
DR
B0
DRIVE
EDGE
SAMPLE
EDGE
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 ...