HD66787 Datasheet, PDF (109/159 Pages) Renesas Technology Corp – 528-channel, One-chip Driver with 262,144-color Display RAM and Power Supply Circuit for Low-temperature Poli-Si TFT (LTPS-TFT) Panels with Incorporat

HD66787
Number of Dummy Write Operations in High-Speed RAM Write (HEA Bits)
HEA1
0
0
1
1
HEA0
0
1
0
1
Number of Dummy Write Operations
Inserted
3
2
1
0
Preliminary
The number of RAM access when writing data in the horizontal direction must be made 4 × N times by
including the dummy writes.
Horizontal RAM write = start dummy write + write data + end dummy write = 4 × N (times)
An example of RAM write in high speed RAM write mode with the window address is as follows.
The RAM data in the specified window-address range is written over consecutively in high speed by
inserting two dummy writes at the start of the line and three dummy writes at the end of the line. The
number of dummy writes is specified with the window-address range specifying bits. In this case, set
HSA1-0 to 10, HEA1-0 to 00.
Writing data in the horizontal direction
AM = 0, ID0 = 1
Window address range setting
HSA = h12, HEA = h30
VSA = h08, VEA = hA0
High-speed RAM write mode setting
HWM = 1
Address set
AD = h0810 *^Note
Dummy RAM write X 2
RAM write X 31
h0000
h0812
GRAM address map
X 153
Specified window address
range (rewrite area)
hA030
Window address range setting
HAS = h12, HEA = h30
VSA = h08, VEA = hA0
hEFAF
Dummy RAM write X 3
Note: In the high-speed RAM write mode, the address set must be either 00 or 11
in ID0 bit setting. Only the RAM address range specified by window addresses
will be overwritten.
High-Speed RAM Write with Window Address Function
Rev.0.22, May.23.2003, page 109 of 159