HD66773R Datasheet, PDF (23/133 Pages) Renesas Technology Corp – 262,144-color, 132 x 176-dot Graphics Controller Driver for TFT LCD panels

HD66773R
Instructions
Outline
The HD66773R adapts 18-bit bus architecture that enables high-speed interfacing with a high-performance
microcomputer. Data sent from external (18/16/9/8 bits) are stored temporarily in the instruction register
(IR) and the data register (DR) to store control information before internal operation starts. Since internal
operation is decided according to the signal sent from the microcomputer, register selection signal (RS),
read/write signal (R/W), and internal 16-bit data bus signal (DB15 to DB0) are called instruction. GRAM
is accessed through internal 18-bit data bus. There are eight categories of instructions:
1. Specify index
2. Read status
3. Control display
4. Control power management
5. Process graphics data
6. Set internal GRAM addresses
7. Transfer data to and from internal GRAM
8. Set grayscale level for internal grayscale γ-adjustment
Normally, the 7^th instruction to write data to be displayed is executed the most frequently. The address of
internal GRAM is updated automatically after data are written to internal GRAM. With window address
function, this reduces the amount of data transmission to minimum and thereby lightens the load on the
program in the microcomputer. Since instructions are executed in 0 cycle, it is possible to write
instructions consecutively.
As the following figure shows, the assignment to the 16 instruction bits (IB15-0) varies according to the
interface to be used. An instruction must adopt the data format for each interface.
Rev.1.10, Jun.21.2003, page 23 of 133