Hi,
I have questions about C6670 Viterbi Coprocessor(VCP2).
The questions are about setting up the "generator polynomials(Gn)"value to the VCP2 control registers which is needed for VCP2 operation.
And the questions are related to the setup at the time of encode/decode written in the WiMAX standard(802.16-2009.pdf).
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IEEE Standard for Local and metropolitan area networks
Part 16: Air Interface for Broadband Wireless Access Systems）
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Question#1:
In WiMAX Standard(802.16-2009.pdf) page.1032 "8.4.9.2.1 Convolutional coding (CC)", generator polynomials(G0, G1) are written.
If setting the above G0 and G1 to the VCP2 Control Register, is following VCP2 Control Register's value correct ?
If not correct, what is the correct value to setup to the VCP2 Control Register?
Condition:
rate = 1/2
G1 = 171[oct]
G2 = 133[oct]
VCP2 Control Register Value:
VCPIC0 = 0x0000D46C
By the way, Encode's diagram(Figure 287-Convolutional encoder of rate 1/2) are written on page.1032 of WiMAX Standard(802.16-2009.pdf).
Question#2:
To set the constraint length(K) to the VCP2, which parameter should I set?
Or, does VCP2 calculate internally from the value of G1 and G2?
Question#3:
In Viterbi Coprocessor(VCP2) User Guide(sprugv6a) page.33 Table 3-4 VCP2 Input Configuration Register 0(VCPIC0) Field Descriptions,
there are note written as following:
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1. The polynomial generators are 9-bit values defined as G(z) = b8z-8 + b7z-7 + b6z-6 + b5z-5 + b4z-4 + b3z-3 + b2z-2 + b1z-1 + b0,
but only 8 bits are passed in the POLYn bitfields so that b1 is the most significant bit and b8 is the least significant bit (b0 is not passed,
but set by the internal VCP hardware).
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Does this mean that "b0" is always set to "1" ?
best regards,
g.f.
