User's Manual

9.3.1.3 A Priori Transfer
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• Word count = 2 * ceil (frame_length/2)
• BCNT = (Word count /2) (No of arrays of length ACNT)
• DESTINATION ADDRESS: TCPSP (5001 0000h)
• SRCBIDX = 8 (Source 2nd Dimension Index)
• DSTBIDX = 8 (Destination 2nd Dimension Index)
• SRCCIDX = 8 (Source 3rd Dimension Index)
• DSTCIDX = 8 (Destination 3rd Dimension Index)
• CCNT = 8 (No of frames in a block)
• BCNTRLD: Don't care
• LINK ADDRESS: See cases 1 and 2 below
Upon completion, this EDMA3 transfer is linked to one of the following:
1. The EDMA3 input configuration parameters transfer parameters of the next user-channel, if there is
one ready to be decoded and the current decoding is a MAP0 from the first iteration.
2. Dummy EDMA3 transfer parameters, if there are no more user channels ready to be decoded.
This EDMA3 transfer to the a priori memory is a TCPXEVT chained and frame-synchronized transfer. This
EDMA3 transfer is chained from the systematic and parity data transfer and occurs only when executing
any MAP but the MAP0 of the first iteration; that is, the OPMOD bits in TCPIC0 must be set to 2h, 4h, and
6h respectively. The parameters should be set as:
• OPTIONS:
– ITCCEN = 0 (Intermediate transfer complete chaining is disabled)
– TCCEN = 0 (Transfer complete chaining is disabled)
– ITCINTEN = 0 (Intermediate transfer complete interrupt is disabled)
– TCINTEN = 1 (Transfer complete interrupt is enabled)
– TCC = 1 to 63 (Transfer Complete Code)
– TCCMODE = 0 (Normal Completion)
– FWID = Don't care
– STAT = 0 (Entry is updated as normal)
– SYNCDIM = 1 (A-Sync. Each event triggers the transfer of ACNT elements.)
– DAM = 0 (Dst addressing within an array increments. Dst is not a FIFO.)
– SAM = 0 (Src addressing within an array increments. Source is not a FIFO.)
• SOURCE ADDRESS: A priori start address (must be double-word aligned)
• If the OPMOD == FIRST_SUB_FRAME
ACNT = 8 * ceil ((frame_length + prolog_length)/8) ⇒ (No of bytes in an array)
• If the OPMOD == MIDDLE_SUB_FRAME
ACNT = 8 * ceil ((frame_length + 2 * prolog_length)/8) ⇒ (No of bytes in an array)
• If the OPMOD == LAST_SUB_FRAME
ACNT = 8 * ceil ((frame_length + prolog_length)/8) ⇒ (No of bytes in an array)
• BCNT = 1 (No of arrays of length ACNT)
• DESTINATION ADDRESS: TCPAP (5004 0000h)
• SRCBIDX = 0 (Source 2nd Dimension Index)
• DSTBIDX = 0 (Destination 2nd Dimension Index)
• SRCCIDX = 0 (Source 3rd Dimension Index)
• DSTCIDX = 0 (Destination 3rd Dimension Index)
• CCNT = 1 (No of frames in a block)
• BCNTRLD: Don't care
• LINK ADDRESS: See cases 1 and 2 below
Upon completion, this EDMA3 transfer is linked to one of the following:
72 TMS320C6457 Turbo-Decoder Coprocessor 2 SPRUGK1 – March 2009
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