S1D13700F01 Epson Electronics America, Inc., S1D13700F01 Datasheet - Page 65

• Manufacturer Part Number: S1D13700F01
• Description: Embedded Memory Graphics Lcd Controller
• Manufacturer: Epson Electronics America, Inc.

Epson Research and Development
Vancouver Design Center
CGRAM ADR
bits 15-0
Hardware Functional Specification
Issue Date: 2005/12/13
REG[19h] Character Generator RAM Start Address Register 0
Address = 8019h
REG[1Ah] Character Generator RAM Start Address Register 1
Address = 801Ah
7
7
6
6
Default = 00h
Default = 00h
The CGRAM ADR command sets the start address of the character generator RAM
(CGRAM) when indirect addressing is used. The values from REG[19h] through
REG[1Ah] are passed as parameters when the CGRAM ADR command is issued. For
further information on the CGRAM ADR command, see Section 11.1.8, “CGRAM ADR”
on page 74.
For example, to determine the address of a 8x8 character at character code index 80h with
a CGRAM start address of 6000h, the following calculation can be used.
character start = (character code index x character height) + CGRAM start address
The character starts in RAM at address 6400h and takes 8 memory locations.
Character Generator RAM Start Address bits [15:0]
These bits determine the memory start address of the Character Generator RAM
(CGRAM). The exact memory location of the start of each character stored in CGRAM
can be calculated by multiplying the character code index by the character height and add-
ing the total to the CGRAM start address.
5
5
= (80h x 8) + 6000h
= 400h + 6000h
= 6400h
CGRAM Start Address bits 15-8 (MSB)
CGRAM Start Address bits 7-0 (LSB)
4
4
Revision 4.05
3
3
2
2
1
1
Read/Write
Read/Write
X42A-A-002-04
S1D13700F01
0
0
Page 65