W99681CF Datasheet, PDF (40/78 Pages) Winbond – JPEG USB Dual Mode Camera Chip

W99681CF
1 DRAM Start Address Setup. Program the 21-bit WORD address to BA + 18H (bits 7-0), BA
+ 19H (bits 15-8), then BA + 1AH (bits 20-16).
2 Read Access Mode Setup. Program 0 to bit 0 of BA + 1BH to select read mode.
W99681CF then starts accessing 16-bit DRAM data into the internal latches, and the
internal DRAM address will be increased by 1 automatically after the access.
3 Read Low-Byte DRAM Data. Read low-byte DRAM data from BA + 1CH location.
4 Read High-Byte DRAM Data. Read high-byte DRAM data from BA + 1DH location. The
W99681CF starts accessing the next-address DRAM data and the internal DRAM address
will be increased by 1 automatically after the access.
5 Read Contiguous DRAM Data. Repeat steps 3 and 4 for contiguous DRAM data
accesses.
Write Access (uC writes data to DRAM)
1 DRAM Start Address Setup. Program the 21-bit WORD address to BA + 18H (bits 7-0), BA
+ 19H (bits 15-8), then BA + 1AH (bits 20-16).
2 Write Access Mode Setup. Program 1 to bit 0 of BA + 1BH to select write mode.
3 Write Low-Byte DRAM Data. Write low-byte DRAM data into BA + 1CH location.
4 Write High-Byte DRAM Data. Write high-byte DRAM data into BA + 1DH location. The
W99681CF then starts writing the 16-bit data into DRAM and the internal DRAM address
will be increased by 1 automatically after the access.
5 Write Contiguous DRAM Data. Repeat steps 3 and 4 for contiguous DRAM data
accesses.
7.8.5 IHV-Specific Information
The microcontroller can provide IHV-specific information including Vendor ID, Product ID, Device
release number, and string descriptors of manufacturer, product, and device′s serial number as that of
E²PROM to save the cost of an E²PROM. Maximum 128 bytes information can be provided and data
structure is the same as that of E²PROM shown in Table 7.14. All IHV-specific information must be
written to the W99681CF via the Vendor String Data Port register (CR0F) in word-aligned sequence
right after hardware reset and base address is set up.
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