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Colour Index Latency Correction with bitmap_addr #115

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WillGreen opened this issue Sep 17, 2022 · 1 comment
Open

Colour Index Latency Correction with bitmap_addr #115

WillGreen opened this issue Sep 17, 2022 · 1 comment
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@WillGreen
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We use bitmap_addr to calculate the memory address from drawing coordinates. Address calculation requires three cycles, so we delay write enable (we) to match. We need to delay the colour index (cidx) similarly.

Current examples use a single colour for a shape, and the initialisation steps hide this issue. However, this bug is evident when a shape is drawn with multiple colours.
@WillGreen WillGreen added the bug Something isn't working label Sep 17, 2022
@WillGreen WillGreen self-assigned this Oct 16, 2022
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The Sinescroll demo doesn't suffer from this issue and provides a template for a fix.
See code under: // delay pixel colour to match address calculation

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