Functional Description
12-30
ADSP-BF537 Blackfin Processor Hardware Reference
Clock Signal Options
Each SPORT has a transmit clock signal (
TSCLK
) and a receive clock signal
(
RSCLK
). The clock signals are configured by the
TCKFE
and
RCKFE
bits of
the
SPORTx_TCR1
and
SPORTx_RCR1
registers. Serial clock frequency is con-
figured in the
SPORTx_TCLKDIV
and
SPORTx_RCLKDIV
registers.
L
The receive clock pin may be tied to the transmit clock if a single
clock is desired for both receive and transmit.
Both transmit and receive clocks can be independently generated inter-
nally or input from an external source. The
ITCLK
bit of the
SPORTx_TCR1
configuration register and the
IRCLK
bit in the
SPORTx_RCR1
configuration
register determines the clock source.
When
IRCLK
or
ITCLK
=
1
, the clock signal is generated internally by the
processor, and the
TSCLK
or
RSCLK
pin is an output. The clock frequency is
determined by the value of the serial clock divisor in the
SPORTx_RCLKDIV
register.
When
IRCLK
or
ITCLK
=
0
, the clock signal is accepted as an input on the
TSCLK
or
RSCLK
pins, and the serial clock divisors in the
SPORTx_TCLKDIV
/
SPORTx_RCLKDIV
registers are ignored. The externally gen-
erated serial clocks do not need to be synchronous with the system clock
or with each other. The system clock must have a higher frequency than
RSCLK
and
TSCLK
.
Frame Sync Options
Framing signals indicate the beginning of each serial word transfer. The
framing signals for each SPORT are
TFS
(transmit frame sync) and
RFS
(receive frame sync). A variety of framing options are available; these
options are configured in the SPORT configuration registers
(
SPORTx_TCR1, SPORTx_TCR2, SPORTx_RCR1
and
SPORTx_RCR2
). The
TFS
and
RFS
signals of a SPORT are independent and are separately configured
in the control registers.
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 ...