HD66773R Datasheet, PDF (67/133 Pages) Renesas Technology Corp – 262,144-color, 132 x 176-dot Graphics Controller Driver for TFT LCD panels

HD66773R
High-Speed Burst RAM Write Function
The HD66773R incorporates the high-speed burst RAM-write function, which writes data to RAM in one-
fourth the access time required for the standard RAM-write operation. This function is especially useful for
applications which require the high-speed rewrite of the display data such as display of colored moving
picture and so on.
In high-speed RAM write mode (HWM), data to be written to RAM is temporarily stored to the internal
register of HD66773R. The data storage in the register is executed by word. When the data storage
operation is executed 4 times, all the data stored in the register is written to RAM at once. While the data is
being written from the register to RAM, another set of data is being written to the register. This function
enables high-speed and consecutive RAM write, which is required in displaying moving pictures and so on.
a)Operational flow of high-speed consecutive RAM write
Microcomputer
18
AAddddrreessss
ccoo(uAunnCtte)err
㧔AC㧕
16
Register 1
Register 2
Register 3
72
Register 4
""00000000""HH "0001"H "0002"H ^{""00000033""HH}
GRAM
Rev.1.10, Jun.21.2003, page 67 of 133