Programmable Clock and Framing
11-53
Multichannel Buffered Serial Ports
11.5 Programmable Clock and Framing
The McBSP has several means of selecting clocking and framing for both the
receiver and transmitter. Clocking and framing can be sent to both portions by
the sample rate generator. Each portion can select external clocking and/or
framing independently. Figure 11–37 is a block diagram of the clock and frame
selection circuitry.
Figure 11–37.
Clock and Frame Generation
0
1
1
0
CLKXM
0
1
Inset:
FSX pin
FSR pin
CLKR pin
CLKX pin
FSG
FSX_int
CLKX_int
Frame selection
Clock selection
(R/X) IOEN
CLKG
FSR_int
CLKS pin
internal clock source
†
DXR to XSR
FSGM
0
1
FSR_int
CLKR_int
FSRP
1
0
0
1
FSRM
FSRM & GSYNC
FSRP
0
1
FSXP
See inset
FSXP
FSXM
FSXM
generator
Sample
rate
Receive
Transmit
DLB
CLKRM
CLKRM
CLKXM
CLKRP
CLKRP
CLKXP
CLKXP
See inset
See inset
See inset
Yyy_int
DLB
† ’C6201/C6202/C6701 uses CPU clock as the internal clock source to the sample rate generator.
’C6211/C6711 uses CPU/2 clock as the internal clock source to the sample rate generator.