MC68HC908LD64 Datasheet, PDF (276/362 Pages) Freescale Semiconductor, Inc – Microcontrollers

On-Screen Display (OSD)
18.6 OSD Screen Memory Map
The OSD operating screen is mapped to a 1K-byte RAM array from
$0800 to $0BFF. The array is organized as 16 rows by 32 columns, with
two bytes (16-bit) for each row-column location. Figure 18-4 shows the
OSD screen memory map.
COLUMN
0
1
2
3
28
29
30
31
DISPLAY RAM
ADDRESS
$840 – $87F
$880 – $8BF
$8C0 – $8FF
$900 – $93F
$940 – $97F
$980 – $9BF
$9C0 – $9FF
$A00 – $A3F
$A40 – $A7F
$A80 – $ABF
$AC0 – $AFF
$B00 – $B3F
$B40 – $B7F
$B80 – $BBF
NOT MAPPED
ROW
0 ACACACAC
ACAC
1 ACACACAC
ACAC
2 ACACACAC
ACAC
3 ACACACAC
ACAC
4 ACACACAC
ACAC
5
6
A
A
C
C
A
A
C
C
A
A
CC_{D I}AA_{S P}CC _{L A Y}
ACAC
ACAC
7
8
A
A
C
C
A
A
C
C
AA_R CC_{E G}AA _I CC_{S T E R S}
ACAC
ACAC
9 ACACACAC
ACAC
10 A C A C A C A C
ACAC
11 A C A C A C A C
ACAC
12 A C A C A C A C
ACAC
13 A C A C A C A C
ACAC
14 A C A C A C A C
ACAC
15
CONTROL, WINDOW, AND PATTERN REGISTERS
A = Character ATTRIBUTE C = Character CODE
Figure 18-4. Memory Map of OSD Registers
The area covering row0-column0 and row14-column29 are called the
active display registers. Each 16-bit display register defines the
character to be displayed, with an character code (character from font
memory) and an attribute code for that character. Column30 of each row
is the attribute register for the entire row. Row15 registers (not memory
mapped) are used for control, window, and pattern for the entire OSD
screen. See 18.8 OSD Registers for register definitions.
The CPU have direct access to the all screen memory registers ($0800
to $0BFF) when the OSDMEN bit in the OSD control register is clear.
When the OSD circuitry is displaying the characters (OSDMEN=1),
updates to display is by indirectly writing to these registers. The OSD
data registers, row register, column register are used for this purpose.
See 18.7.3 OSD Data Registers (OSDDRH:OSDDRL), 18.7.4 OSD
Row Address Register (OSDRAR), and 18.7.5 OSD Column Address
Register (OSDCAR).
Data Sheet
276
On-Screen Display (OSD)
MC68HC908LD64 — Rev. 3.0
Freescale Semiconductor