C-Boot ROM Description
616
SPRUHE8E – October 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
ROM Code and Peripheral Booting
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Sine/Cosine Table, IQ Math Table
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Table size: 1282 words
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Q format: Q30
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Contents: 32-bit samples for one and a quarter period sine wave
This is useful for accurate sine wave generation and 32-bit FFTs. This can also be used for 16-bit
math, just skip over every second value.
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Normalized Inverse Table, IQ Math Table
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Table size: 528 words
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Q format: Q29
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Contents: 32-bit normalized inverse samples plus saturation limits
This table is used as an initial estimate in the Newton-Raphson inverse algorithm. By using a more
accurate estimate the convergence is quicker and hence cycle time is faster.
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Normalized Square Root Table, IQ Math Table
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Table size: 274 words
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Q format: Q30
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Contents: 32-bit normalized inverse square root samples plus saturation
This table is used as an initial estimate in the Newton-Raphson square-root algorithm. By using a more
accurate estimate the convergence is quicker and hence cycle time is faster.
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Normalized Arctan Table, IQ Math Table
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Table size: 452 words
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Q format: Q30
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Contents 32-bit second order coefficients for line of best fit plus normalization table
This table is used as an initial estimate in the Arctan iterative algorithm. By using a more accurate
estimate the convergence is quicker and hence cycle time is faster.
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Rounding and Saturation Table, IQ Math Table
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Table size: 360 words
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Q format: Q30
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Contents: 32-bit rounding and saturation limits for various Q values
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Exp Min/Max Table, IQMath Table
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Table size: 120 words
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Q format: Q1 - Q30
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Contents: 32-bit Min and Max values for each Q value
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Exp Coefficient Table, IQMath Table
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Table size: 20 words
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Q format: Q31
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Contents: 32-bit coefficients for calculating exp (X) using a taylor series
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Inverse Sin/Cos Table, IQ Math Table
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Table size: 85 x 16
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Q format: Q29
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Contents: Coefficient table to calculate the formula f(x) = c4*x^4 + c3*x^3 + c2*x^2 + c1*x + c0.
6.6.1.2
On-Chip C-Boot ROM IQmath Functions
The following IQmath functions are included in the Boot ROM:
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IQNatan2 N= 15, 20, 24, 29
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IQNcos N= 15, 20, 24, 29
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IQNdiv N= 15, 20, 24, 29