DS604 Datasheet, PDF (7/12 Pages) –

3GPP2 Turbo Encoder v2.0
RSC2 Parity0 Output (RSC2_PARITY0)
RSC2_PARITY0 is the Y0 output from RSC2. (See Figure 3.)
RSC2 Parity1 Output (RSC2_PARITY1)
RSC2_PARITY1 is the Y1 output from RSC2. (See Figure 3.)
RSC1 Tail Output (RSC1_TAIL)
RSC1_TAIL is asserted High for three cycles at the end of each output block to indicate trellis termina-
tion of RSC1.
DRSC2 Tail Output (RSC2_TAIL)
RSC2_TAIL is asserted High for three cycles at the end of each output block to indicate trellis termina-
tion of RSC2.
is_{Ready (RDY)}
This signal is asserted High when there is valid data on the SYSTEMATIC and PARITY output ports.
c^{RDY is asserted for block size+6 valid clock cycles each block, to include the tail bits.}
Ready For Data In (RFD_IN)
o _{RFD_IN is an optional pin which can be used to inhibit the output of the core while allowing current}
input operations to continue. RFD_IN is intended to be used as a means for a downstream system using
n the encoded data to indicate that it is not ready to handle any further data. If RFD_IN is Low, all sys-
tematic and parity outputs, RSC1_TAIL, RSC2_TAIL, and RDY outputs are inhibited. The operation of
RFD_IN is described in further detail later in this document.
ti _{Functional Description}
n _{Double-Buffering}
Figure 4 illustrates the LOAD and OUTPUT operations.
u _{Data blocks are written alternately to the two symbol memories, MEM0 and MEM1, and also read out}
alternately, thereby, maximizing the data throughput.
e _{If the block size increases or the core is inhibited by negating ND, the LOAD operation may take longer}
than the OUTPUT operation, in which case, the RDY output port may be driven Low to indicate the OUT-
d _{PUT operation is complete. Similarly, if the block size decreases or the core is inhibited by negating}
RFD_IN, the OUTPUT operation may take longer than the LOAD operation. In which case, the RFD port
may be driven Low to indicate that the LOAD operation is complete and the core is no longer ready for
I ^{data. The effect of changing the block size is shown in Figure 4(a), and the effects of ND and RFD_IN are}
P ^{shown in Figure 4(b)}
DS604 April 2, 2007
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Product Specification