Underflow in the Transmitter
McBSP Exception/Error Conditions
4-10
SPRU592E
4.5.1 Example of the Underflow Condition
7 shows an underflow condition. After B is transmitted, DXR1 is not
reloaded before the subsequent frame-sync pulse. Thus, B is again
transmitted on DX.
Figure 4
−
7. Underflow During McBSP Transmission
XEMPTY
Á
Á
B5
B6
B7
B0
B1
B2
B3
B4
B5
B6
B7
A0
A1
XRDY
DX
FSX
CLKX
ÁÁ
ÁÁ
Write to DXR1(C)
DXR1 to XSR1 copy(B)
4.5.2 Example of Preventing the Underflow Condition
8 shows the case of writing to DXR1 just before an underflow
condition would otherwise occur. After B is transmitted, C is written to DXR1
before the next frame-sync pulse. As a result, there is no underflow; B is not
transmitted twice.
Figure 4
−
8. Underflow Prevented in the McBSP Transmitter
XEMPTY
Á
Á
Á
Á
C5
C6
C7
B0
B1
B2
B3
B4
B5
B6
B7
A0
A1
XRDY
DX
FSX
CLKX
Á
Á
Á
Á
DXR1 to XSR1 copy(C)
Write to DXR1(C)
DXR1 to XSR1 copy
Summary of Contents for TMS320VC5509
Page 5: ...vi This page is intentionally left blank ...
Page 43: ...McBSP Operation 2 20 SPRU592E This page is intentionally left blank ...
Page 105: ...SPI Operation Using the Clock Stop Mode 6 16 SPRU592E This page is intentionally left blank ...
Page 187: ...Transmitter Configuration 8 40 SPRU592E This page is intentionally left blank ...
Page 191: ...General Purpose I O on the McBSP Pins 9 4 SPRU592E This page is intentionally left blank ...
Page 201: ...Emulation Power and Reset Considerations 10 10 SPRU592E ...
Page 207: ...Data Packing Examples 11 6 SPRU592E This page is intentionally left blank ...
Page 273: ...McBSP Register Worksheet 13 14 SPRU592E This page is intentionally left blank ...