W99681CF Datasheet, PDF (3/78 Pages) Winbond – JPEG USB Dual Mode Camera Chip

W99681CF
TABLE OF CONTENTS
1 GENERAL DESCRIPTION.............................................................................................................. 7
2 FEATURES ....................................................................................................................................... 8
3 PIN CONFIGURATION .................................................................................................................. 10
4 PIN DESCRIPTION ........................................................................................................................ 11
4.1 PIN DEFINITION.................................................................................................................................. 11
4.2 PIN LIST............................................................................................................................................. 16
4.3 POWER-ON RESET INITIALIZATION ..................................................................................................... 17
5 SYSTEM DIAGRAM....................................................................................................................... 18
6 BLOCK DIAGRAM......................................................................................................................... 19
7 FUNCTIONAL DESCRIPTION...................................................................................................... 20
7.1 VIDEO INPUT INTERFACE.................................................................................................................... 20
7.1.1 Camera Control Serial Bus...................................................................................................... 20
7.1.2 Input Video Data Format.......................................................................................................... 20
7.1.3 Cropping.................................................................................................................................... 21
7.1.4 Scaling....................................................................................................................................... 21
7.1.5 Filtering...................................................................................................................................... 22
7.1.6 Captured Video Data Format................................................................................................... 22
7.2 DRAM CONTROL AND INTERFACE ..................................................................................................... 23
7.2.1 DRAM Access Arbitration ........................................................................................................ 23
7.2.2 DRAM Interface ........................................................................................................................ 23
7.3 JPEG COMPRESSION........................................................................................................................ 25
7.3.1 Level Shift and Forward DCT .................................................................................................. 25
7.3.2 Quantization.............................................................................................................................. 25
7.3.3 Huffman Encoding.................................................................................................................... 26
7.3.4 JPEG Encoding Order.............................................................................................................. 26
7.4 USB INTERFACE AND DEVICE CONTROL............................................................................................ 27
7.4.1 Endpoints..................................................................................................................................... 27
7.4.1.1 Default Endpoint (Endpoint 0)............................................................................................................27
7.4.1.2 Video Data-In Endpoint (Endpoint 1).................................................................................................27
7.4.2 USB Device Requests.............................................................................................................. 27
7.4.2.1 Standard Device Requests ................................................................................................................27
7.4.2.2 Video Camera Class-Specific Requests ...........................................................................................29
7.4.2.3 Vendor-Specific Requests .................................................................................................................29
7.4.3 Descriptors................................................................................................................................ 30
7.4.3.1 Device Descriptors .............................................................................................................................30
7.4.3.2 Configuration Descriptors ..................................................................................................................31
7.4.3.3 String Descriptors...............................................................................................................................33
7.5 VIDEO/STILL IMAGE DATA TRANSFER................................................................................................. 34
Publication Release Date: March 2000
-3-
Revision A1