83C055 Philips Semiconductors, 83C055 Datasheet - Page 30

• Manufacturer Part Number: 83C055
• Description: Microcontrollers for TV and video MTV
• Manufacturer: Philips Semiconductors

Philips Semiconductors
15 PROGRAMMING THE OSD EPROM
15.1
The OSD EPROM space starts at location C000H and
ends at location CFFFH. However, due to the addressing
scheme of the OSD, not all locations within this space are
used.The start location of the next character can be
calculated by adding 40H to the start location of the
previous character. For example, character 1 starts at
C000H; then characters 2, 3, and 4 start at C040H,
C080H, and C0C0H, respectively.
15.2
An example of an OSD character bit map, and the program
data to obtain that character is shown in Table 34.
15.3
The mapping for the full OSD EPROM is shown in Table 35. To program the example character into the first character
location of the OSD EPROM would require the data at the address as shown in Table 34.
Table 34 Example of an OSD Character Bit Map (note 1)
Note
1. X can be a logic 0 or logic 1, and will Program and Verify correctly.
1996 Mar 22
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Line 9
Line 10
Line 11
Line 12
Line 13
Line 14
Line 15
Line 16
Line 17
Line 18
Microcontrollers for TV and video (MTV)
LINE
Overview
Character description and programming
OSD EPROM bit map
(BIT 14 TO 8)
0000000
0000000
0011110
0011110
0011110
0011110
0011110
0011110
0011111
0011111
0011111
0011110
0011110
0011110
0011110
0011110
0000000
0000000
UPPER
CHARACTER BIT MAP
(BIT 7 TO 1)
0000000
0000000
0001100
0001100
0001100
0001100
0001100
0001100
1111100
1111100
1111100
0001100
0001100
0001100
0001100
0001100
0000000
0000000
LOWER
X0000000
X0000000
X0011110
X0011110
X0011110
X0011110
X0011110
X0011110
X0011111
X0011111
X0011111
X0011110
X0011110
X0011110
X0011110
X0011110
X0000000
X0000000
UPPER
PROGRAM DATA
30
Each character is 14 bits wide by 18 lines high.A character
is split about a vertical axis into two sections UPPER and
LOWER as illustrated in Table 34:
During Programming and Verification, each section is
programmed using bytes of program data. The MSB of the
program data is not used; however, the MSB location
physically exists, and so will Program and Verify.
Each section contains 7 bits of the character, such that:
– the LOWER section contains bits 7 to 1, and
– the UPPER section contains bits 14 to 8.
The LOWER section of the character is programmed
when the LSB of the program address equals a logic 0,
and the UPPER section when the LSB equals a logic 1.
X0000000
X0000000
X0001100
X0001100
X0001100
X0001100
X0001100
X0001100
X1111100
X1111100
X1111100
X0001100
X0001100
X0001100
X0001100
X0001100
X0000000
X0000000
LOWER
UPPER
C00B
C00D
C01B
C01D
C001
C003
C005
C007
C009
C00F
C013
C015
C017
C019
C01F
C021
C023
C011
83C145; 83C845
83C055; 87C055
ADDRESS (HEX)
Product specification
LOWER
C00A
C00C
C00E
C01A
C01C
C01E
C000
C002
C004
C006
C008
C010
C012
C014
C016
C018
C020
C022