Coefficient Interface - Xilinx LogiCORE IP User Manual

Chapter 8: Coefficients
If the user specifies in the CORE Generator or EDK GUI that the Luma and Chroma filters
share common coefficients, then there is no coefficient memory space available for chroma
coefficients. In this case, the user must not load chroma coefficients using the Coefficient
interface, and must not specify chroma coefficients in the .coe file.
Similarly, if the user has specified in the CORE Generator or EDK GUI that the Horizontal
and Vertical filters share common coefficients, then there is no coefficient memory space
available for Vertical coefficients. In this case, the user must not load Vertical coefficients
using the Coefficient interface, and must not specify Vertical coefficients in the .coe file.
Note:
taps.

Coefficient Interface

The scaler uses only one set of coefficients per frame period. To change to a different set of
stored coefficients for the next frame, use the h_coeff_set and v_coeff_set dynamic
register inputs.
You may load new coefficients into a different location in the coefficient store during some
frame period before they are required. You may load a maximum of one coefficient set
(including all of HY, HC, VY, VC components) per frame period. Subsequently, this
coefficient set may be selected for use by controlling h_coeff_set and v_coeff_set.
Filter Coefficients may be loaded into the coefficient memory using the coefficient memory
interface. This comprises:
The 32-bit input word always holds two coefficients. The scaler supports 16-bit coefficient
bit-widths. The word format is shown in
X-Ref Target - Figure 8-1
42
This option is only available if the number of horizontal taps is equal to the number of vertical
coef_data_in(31:0) 32-bit coefficient input bus
coef_wr_en Coefficient write-enable
coef_set_wr_addr(3:0) Coefficient set write address
31
Valid - Coefficient n+1
Figure 8-1: Coefficient Write-Format on coef_data_in(31:0)
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Figure 8-1.
15
Valid - Coefficient n
16-bit Coefficients
Video Scaler v4.0 User Guide
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UG_28_031909
UG805 March 1, 2011