ADSP-BF535 Blackfin Processor Hardware Reference
11-63
Serial Port Controllers
In multichannel mode, late (alternative) frame mode is entered automati-
cally; the first bit of the transmit data word is available and the first bit of
the receive data word is sampled in the same serial clock cycle that the
frame sync is asserted, provided that
MFD
is set to 0.
The
TFS
signal is used as a transmit data valid signal which is active during
transmission of an enabled word. The SPORT’s
DT
pin is three-stated
when the time slot is not active, and the
TFS
signal serves as an output
enabled signal for the
DT
pin. The SPORT drives
TFS
in multichannel
mode whether or not
ITFS
is cleared.
Once the initial
FS
is received, and a frame transfer has started, all other
FS
signals are ignored by the SPORT until the complete frame has been
transferred.
In multichannel mode, the
RFS
signal is used for the block or frame start
reference, after which the transfers are performed continuously with no
FS
required. Therefore, internally generated frame syncs are always data
independent.
Multichannel Frame Delay
The 4-bit
MFD
field in the multichannel configuration control register
specifies a delay between the frame sync pulse and the first data bit in mul-
tichannel mode. The value of
MFD
is the number of serial clock cycles of
the delay. Multichannel frame delay allows the processor to work with dif-
ferent types of interface devices.
A value of 0 for
MFD
causes the frame sync to be concurrent with the first
data bit. The maximum value allowed for
MFD
is 15. A new frame sync may
occur before data from the last frame has been received, because blocks of
data occur back-to-back.
Summary of Contents for ADSP-BF535 Blackfin
Page 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Page 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Page 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Page 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Page 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Page 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Page 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Page 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Page 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Page 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Page 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Page 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Page 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...