HD66773R Datasheet, PDF (79/133 Pages) Renesas Technology Corp – 262,144-color, 132 x 176-dot Graphics Controller Driver for TFT LCD panels

HD66773R
5. Read/Write mode 1: AM = 0, LG2–0 = 001/010/011
This mode is used when data are horizontally written in high-speed with performing logical operation on
the GRAM data (base data) and data from the microcomputer. The logical operation is performed on the
GRAM read-out data and the data sent from the microcomputer, and the result of the logical operation is
written to GRAM. In the read operation, the GRAM data is not read out to the microcomputer but retained
temporarily in the read-data latch of the HD66773R. Accordingly, the read operation can be performed
using the same pulse width with the write-access pulse (68-system: ENABLE “High” level width, 80-
system: ENABLE “Low” level width), but requires the same bus cycle time as the normal read operation.
In this operation, the write-data mask function (WM15–0) is available. After writing, the address counter
(AC) automatically increments by 1 (I/D = 1) or decrements by 1 (I/D = 0), and jumps to the counter at the
opposing edge of the next one-raster-row below after when the counter reaches either left or right edge of
GRAM.
Operation Examples:
1) I/D = "1", AM = "0", LG2-0 = "001"(OR)
2) WM15-0 = "0000"H
3) AC = "0000"H
WM15
Write-data mask: _{0 0 0 0 0 0 0 0}
WM0
0 00 0 0 0 0 0
Read data (1):
DB17 DB10 DB8
DB1
1 00 11 00 1 0 10 0 0 00 0
Write data (1):
1 01 11 10 0 0 11 0 0 00 0
Read data (2):
Write data (2):
0 00 01 11 1 0 00 0 0 0 0 0
1 10 0 0 0 1 1 1 0 0 0 0 0 0 0
Logical
operation(OR)
1 01 11 10 10 11 0 00 00
Logical
operation(OR)
11 0 011 1 11 00 0 00 00
"0000"H
10 1 11 10 10 11 00 00 0
Read data (1) + Write data (1)
"0001"H
11 0 011 1 11 00 00 00 0
Read data (2) + Write data (2)
GRAM
Rev.1.10, Jun.21.2003, page 79 of 133