diff --git a/OV7670.md b/OV7670.md
index f7431a2..e97fadc 100644
--- a/OV7670.md
+++ b/OV7670.md
@@ -18,3 +18,4 @@
 - Links:
     - https://therandomlab.blogspot.com/2016/06/arduvision-ii-ov7670-fifo-module-and.html
     - https://www.play-zone.ch/en/fileuploader/download/download/?d=1&file=custom%2Fupload%2FFile-1402681702.pdf
+    - http://www.haoyuelectronics.com/Attachment/OV7670-Module-A/CMOS_FIFO%20schematic.pdf
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