Texas Instruments TURBO-DECODER COPROCESSOR 2 TMS320C6457 DSP Benutzerhandbuch
9.1
EDMA3 Resources
9.1.1
TCP2 Dedicated EDMA3 Resources
9.1.2
Special TCP2 EDMA3 Programming Considerations
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Programming
Note that several user channels can be programmed prior to starting the TCP2.
Table 42. EDMA3 Parameters in Standalone (SA) Mode
Direction
Transmit (DSP
Transmit (DSP
→
TCP)
Receive (TCP
→
DSP)
Data
Usage
Required/Optional
Transmit
Input configuration
Send the input configuration
Required
parameters
parameters
Transmit
Systematics and parities
Send the systematics and parities
Required
Transmit
Interleaver indexes
Send the interleaver table
Optional INTER bit
Receive
Hard decisions
Read the hard decisions
Required
Receive
Output parameters
Read the output parameters
Optional OUTF bit
Table 43. EDMA3 Parameters in Shared Processing (SP) Mode
Direction
Transmit (DSP
Transmit (DSP
→
TCP)
Receive (TCP
→
DSP)
Data
Usage
Required/Optional
Transmit
Input configuration
Send the input configuration
Required
parameters
parameters
Transmit
Systematics and parities
Send the systematics and parities
Required
Transmit
A prioris
Send the a prioris
Required except for first
iteration MAP1
iteration MAP1
Receive
Extrinsics
Read the extrinsics
Required
Within the available 64 EDMA3 channels event sources, two are assigned to the TCP: event 30 and event
31.
31.
•
Event 30 is associated to the TCP2 receive event (TCPREVT) and is used as the synchronization
event for the EDMA3 transfer from the TCP2 to the DSP (receive).
event for the EDMA3 transfer from the TCP2 to the DSP (receive).
•
Event 31 is associated to the TCP2 transmit event (TCPXEVT) and is used as the synchronization
event for the EDMA3 transfer from the DSP to the TCP2 (transmit).
event for the EDMA3 transfer from the DSP to the TCP2 (transmit).
The EDMA3 parameters consists of eight words as shown in
. In the context of the TCP2, all
EDMA3 transfers should follow ACNT * BCNT number of bytes in A_Sync Mode and ACNT *BCNT *
CCNT number of bytes in AB_Sync Mode. The number of bytes should be a multiple of 8. For more
information, see the TMS320C6457 DSP Enhanced Direct Memory Access (EDMA3) Controller Reference
Guide (
CCNT number of bytes in AB_Sync Mode. The number of bytes should be a multiple of 8. For more
information, see the TMS320C6457 DSP Enhanced Direct Memory Access (EDMA3) Controller Reference
Guide (
Figure 99. EDMA3 Parameters Structure
31
0
EDMA3 Channel Options Parameter (OPT)
EDMA3 Channel Source Address (SRC)
Number of arrays of length ACNT (BCNT)
Number of bytes in array (ACNT)
EDMA3 Channel Destination Address (DST)
Destination 2nd Dimension Index (DSTBIDX)
Source 2nd Dimension Index (SRCBIDX)
BCNTRLD
LINK
Destination 3rd Dimension Index (DSTCIDX)
Source 3rd Dimension Index (SRCCIDX)
Reserved
Number of frames in block (CCNT)
SPRUGK1 – March 2009
TMS320C6457 Turbo-Decoder Coprocessor 2
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