Texas Instruments OMAP5912 Reference Manual page 1668

Figure 30. Underflow Prevented in the McBSP Transmitter
CLKX
FSX
A1
DX
XRDY
XEMPTY_
4.5 Unexpected Transmit Frame-Synchronization Pulse
4.5.1 Possible Responses to Transmit Frame-Synchronization Pulses
SPRU762B
Á Á
A0 B7 B6
Á Á
DXR1 to XSR1 copy
section 4.5.1 shows how the McBSP responds to any transmit
frame-synchronization pulses, including an unexpected pulse. Sections 4.5.2
and 4.5.3 show an example of a frame-synchronization error and an example
of how to prevent such an error, respectively.
Figure 31 shows the decision tree that the transmitter uses to handle all
incoming frame-synchronization pulses. The figure assumes that the
transmitter has been started (XRST = 1 in SPCR2). Case 3 in the figure is the
case in which an error occurs.
McBSP Exception/Error Conditions
Á
B5 B4 B3 B2 B1 B0
Á
Write to DXR1(C)
Multichannel Buffered Serial Ports (McBSPs)
Á
C7 C6 C5
Á
DXR1 to XSR1 copy(C)
57