Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
OVERVIEW
16-DIP-300
The KS2508 is used to display some characters or symbols on
a screen of monitor. Basically, the operation is to control the
internal memory on chip and generate the R,G,B signals for
some characters or symbols. The R,G,B signals are synchronized with the horizontal sync. Then the R,G,B signals are
mixed with the main video signal in the Video Amp IC.
The font data for characters or symbols are stored in the internal ROM. This stored data are accessed and controlled by the
control data from a micro controller. The control data are transmitted through the I2C bus. All timing control signals including
the system clock are synchronized with the horizontal sync.
Therefore there is a PLL circuitry on chip.
FEATURES
•
256 ROM fonts (Each font consists of 12 x 18 dots.)
•
Full Screen Memory Architecture
•
Wide range PLL available (15 kHz ~ 120 kHz)
•
Programmable vertical height of character
•
Programmable vertical and horizontal positioning
•
Character color selection up to 16 different colors
•
Programmable background color (Up to 16 colors)
•
Character blinking, bordering and shadowing
•
Color blinking
•
Character scrolling
•
Fade-in and fade-out
•
Box drawing
•
Character sizing up to four times
•
96 MHz pixel frequency from on-chip PLL
•
IIC Protocol Data Transmission (Slave Address : BAH)
ORDERING INFORMATION
Device
Package
KS2508 16-DIP-300
Operating Temperature
0°C ~ 70°C
1
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
BLOCK DIAGRAM
SDA 7
RAM
Data
Data
Receiver
SCL 8
16
Control
16 Data
ROM
Addr
RAM
(480 x 16)
9
Font
Control
Font
12 Data
15 INT
Frame
Control
HFLB 6
OSD
_PLL
VFLB 9
H-Pulse
V-Pulse
Control Register
CLK
Row
Control
Display
Control
Display
Controller
Frame
Control
13 G_OUT
12 B_OUT
Timing
Controller
VREF
10
16
VDD_D
VREF1
4
VSS_D
VCO_IN
1
VDD_A
5
14 R_OUT
H/V/CLK
Control
H/V/CLK
Control
VSS_A
3
Output
Stage
11 FBLK
Row
Control
2
Single Color ROM
(256 x 18x12)
Figure 1. Functional Block Diagram
2
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
PIN CONFIGURATIONS
VSS-A
16 VDD_D
1
VCO-IN 2
15 INT
VREF1
3
14 R_OUT
VDD-A
4
13 G_OUT
KS2508
VREF 5
12 B_OUT
HFLB 6
11 FBLK
SDA
7
SCL
8
10 VSS_D
9
VFLB
Figure 2. Pin Configurations
3
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
PIN DESCRIPTIONS
Table 1. Pin Descriptions
Pin No.
Signal
Active
I/O
Description
1
VSS_A
-
-
2
VCO_IN
-
Input
This voltage is generated at the external loop filter and
goes into the input stage of the VCO.
3
VREF1
-
Input
1.26 V DC Voltage from the Bandgap Reference.
Connected to ground through a resistor to make internal
reference current (Typical 36 KΩ for 27µA)
4
VDD_A
-
-
5
VREF
-
Input
Bandgap Reference Voltage (Typical 1.26 V)
6
HFLB
Low
Input
Horizontal Flyback Signal
7
SDA
-
In/Out
Serial Data (I2C)
8
SCL
-
In/Out
Serial Clock (I2C)
9
VFLB
Low
Input
Vertical Flyback Signal
10
VSS_D
-
-
Ground for Digital Part
11
FBLK
-
Output
Fast Blank Signal
12
B_OUT
-
Output
Video Signal Output (B)
13
G_OUT
-
Output
Video Signal Output (G)
14
R_OUT
-
Output
Video Signal Output (R)
15
INT
-
Output
Intensity Signal Output
16
VDD_D
-
-
Ground (Analog Part)
+5 V Supply Voltage for Analog Part
+5 V SUpply Voltage for Dogital Part
4
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
ABSOLUTE MAXIMUM RATINGS
Parameters
Symbol
Value
Unit
Min.
Typ.
Max.
VDD
-
-
7.0
V
VI
-
-
7.0
V
Operating Temperature Range
TOPR
-20
-
70
°C
Storage Temperature Range
TSTG
-40
125
°C
PD
-
1200
mW
Maximum Supply Voltage
Input Voltage
Power Dissipation
-
NOTE: PKG Thermal Resistance : 64.2 °C/W
ELECTRICAL CHARACTERISTICS
DC Electrical Characteristics
(Ta = 25 °C, VDD = 5 V)
Table 2. DC Electrical Characteristics
Parameters (Conditions)
Supply Voltage
Supply Current
(No load on any output)
Input Voltage
Output Voltage
(lout = 1mA)
Input Leakage Current
VCO Input Voltage
Symbol
Min.
Typ.
Max.
Unit
VDD
4.75
5.00
5.25
V
IDD
-
-
25
mA
VIH
0.8VDD
-
-
V
VIL
-
-
VSS + 0.4
V
VOH
0.8VDD
-
-
V
VOL
-
-
VSS + 0.4
V
IIL
-10
-
10
µA
VVCO
2.5
V
5
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
OPERATION TIMINGS
Table 3. Operation Timings
Parameters (Conditions)
Symbol
Min.
Typ.
Max.
Unit
Output Signal - R/G/B_OUT, INT, FBLK (Ta = 25°C VDDA = VDD = 5 V , CLOAD = 30pF)
Rise Time
tR
-
-
6
nsec
Fall Time
tF
-
-
6
nsec
Horizontal Flyback Signal Frequency
fHFLB
-
-
120
kHz
Vertical Flyback Signal Frequency
fVFLB
-
-
200
Hz
fSCL
-
-
300
kHz
Hold Time for start condition
ths
500
-
-
ns
Set Up Time for stop condition
tsus
500
-
-
ns
Low Duration of clock
tlow
400
-
-
ns
High Duration of clock
thigh
400
-
-
ns
Hold Time for data
thd
0
-
-
ns
Set Up Time for data
tsud
500
-
-
ns
Time between 2 access
tss
500
-
-
ns
Fall Time of SDA
tfSDA
-
-
20
ns
Rise Time of both SCL and SDA
trSDA
-
-
-
ns
Input Signal - HFLB, VFLB
I2C Interface - SDA, SCL (Refer to Figure 3)
SCL Clock Frequency
tss
thd
SDA
ths
tsud
SCL
thigh
tlow
Figure 3. I2C Bus Timing Diagram
6
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
FUNCTIONAL DESCRIPTIONS
Data Transmission to the KS2508
According to the I2C protocol, the KS2508 receives the data from a micro controller. The SDA line and the SCL line
are shown in Figure 4. As shown in Figure 4, after the starting pulse, the slave address with R/W* bit and an
acknowledge are transmitted in sequence, an internal register address of the KS2508 is followed. The first 8-bit
byte is the upper 8bits of the register address. The lower 8bits of the register address are followed after the second
acknowledge. There is a data transmission format and are two address bit patterns in the KS2508 as following.
The slave address of the KS2508 is BAH(in hexadecimal).
Data Transmission Format
Row Address -> Column Address -> Data Byte N -> Data Byte N+1 -> Data Byte N+2 -> ....
Address Bit Pattern for Display Registers Data
(a) Row Address Bit Pattern
R3 - R0: Valid Data for Row Address
A15
A14
A13
A12
A11
A10
A9
A8
X
X
X
X
R3
R2
R1
R0
(b) Column Address Bit Pattern
C4 - C0: Valid Data for Column Address
A7
A6
A5
A4
A3
A2
A1
A0
X
X
X
C4
C3
C2
C1
C0
After addressing, data bytes are followed as the above data transmission format. The Figure 4 describes the data
transmission with the I2C bus protocol.
SCL
R/W
SDA
START
IIC SLAVE ADDRESS
ACK
A15 A14 A13 A12 A11 A10 A9
MSB ADDRESS
A8
A7
A6
ACK
A5
A4 A3 A2
LSB ADDRESS
A1
A0
ACK
SCL
...
SDA
D7
D6
D5 D4 D3 D2 D1 D0
DATA BYTE N(MSB DATA)
ACK
D7
D6
D5 D4 D3 D2 D1 D0
DATA BYTE N(LSB DATA)
ACK
D7
D6
D5 D4 D3 D2 D1 D0
DATA BYTE N(MSB DATA)
ACK
...
STOP
Figure 4. SDA line and SCL line (Write Operation)
7
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
Memory Map
The display RAM is addressed with the row and column number in sequence. The display RAM consists of four
register groups: Character & Attribute Registers, Row Attribute Registers and Frame Control Registers-.
As the display area in a monitor screen is 30 columns by 15 rows, the related Character & Attribute Registers are
also 30 columns by 15 rows. Each register contains a character address and an attribute corresponding to display
location on a monitor screen. And one register is composed of 16 bits. The lower 8 bits select characters out of 256
ROM fonts. The upper 7 bits are assigned to give a character attribute to a selected font. Row Attribute Registers
occupy the 31th column of Display RAM and provide the row attribute of a blank mode, raster color, raster color
intensity, character color intensity, horizontal character size, vertical character size.
Frame Control Registers are located at the 16th row. The content of each register is described in Figure 5 and following register set.
00 01 02
27 28 29
30
Row 00
Row 01
Character & Attribute Registers
(30 x 15 Character Display)
Row 13
Row 14
Row 15 00 01 02
Row Attribute
Registers
Frame Control Registers
Figure 5. Memory Map of Display Registers
8
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
ROM Fonts
KS2508 is able to supply 256 single-color ROM fonts for describing an OSD icon. So a multi-language OSD icon
can be generated. The standard font $00 is reserved for blank data.
$00
$01
$02
$0E
$0F
$10
$11
$12
$1E
$1F
$20
$21
$22
$2E
$2F
$E0
$E1
$E2
$EE
$EF
$F0
$F1
$F2
$FE
$FF
Figure 6. Array of ROM Fonts
9
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
Scroll
The scrolling function is to display or erase a character slowly from the top line to the bottom. The scrolling time is
controlled by 'ScrT' bit of the frame control registers. If 'ScrT' bit is high, then the time is 0.5 sec. Otherwise, 1 sec.
Character Bordering & Shadowing
Bordering
Shadowing
10
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
Character Height Control
Two examples of the height-controlled character are shown in the following figure. The height control is performed
by repeating some lines. The repeating line-number comes from the equation below.
[# of the repeating lines = 2 + N × M ] ,
where N = 1,2,3,... and M = round{14÷(CH[5:0]-18)}.
If the M value is less than or equal to 1, all the lines of the standard font are repeated once or more. This is
described as following.
(i) If CH[5:0] is greater than 32, and less than or equal to 46 (32 < CH[5:0] ≤ 46), then all lines are repeated once
or twice. The lines repeated twice are selected by the following equation.
[# of the repeating lines = 2 + N × M ] ,
where N = 1,2,3,... and M= round{14÷(CH[5:0]-32)}.
(ii) If CH[5:0] is greater than 46, and less than or equal to 60 (46 < CH[5:0] ≤ 60), then all lines are repeated twice
or three times. The lines repeated three times are selected by the following equation.
[# of the repeating lines = 2 + N × M ] ,
where N = 1,2,3,... and M= round{14÷(CH[5:0]-46)}.
iii) If CH[5:0] is greater than 60, and less than or equal to 64 (60 < CH[5:0] ≤ 64), then all lines are repeated three
or four times. The lines repeated four times are selected by the following equation.
[# of the repeating lines = 2 + N × M ] ,
where N = 1,2,3,... and M= round{14÷(CH[5:0]-60)}.
The repeating line-number is limited to 16.
11
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
: added
line
Standard font
in high vertical resolution
Standard Font(12*18)
Height-controlled font
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Standard Font(12*18)
: added
line
Standard font
in more higher vertical resolution
Height-controlled font
12
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
FRAME CONTROL & TIMING
Figure 7 shows the composition of display frame with the OSD characters.
HFLB
VP[7:0]
HP[7:0]
15 Rows(15 x 18 dots)
30 Columns(=30 x 12 dots)
OSD Characters
Background Screen
Figure 7. Frame Composition with the OSD Characters
User can determine the dot frequency by the equation of H freq. x the number of horizontal resolution.
And the number of horizontal resolution is determined by the bit9 - 8 (dot 1,dot 0) of the frame Control registers-1.
If dot 0 = “0”, dot 1 = “0”, then the dot frequency is calculated by the equation of H freq. × 320.
If the H freq. = 15 kHz, then the dot frequency is 15 kHz × 320 = 4.8 MHz.
If dot 0 = “1”, dot 1 = “1” and the horizontal frequency is 120 kHz, then the dot frequency is 120 kHz × 800 = 96
MHz. 96 MHz is the maximum clock frequency in this processor.
13
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
REGISTER DESCRIPTION
¡ß Character & Attribute Register : Row00~14, Column00~29
F
E
D
BINV BOX1 BOX0
C
B
A
9
8
7
6
B
G
R
Blink
-
C7
C6
Character Attribute
5
4
3
2
1
0
C5
C4
C3
C2
C1
C0
Character Code 256 Fonts)
¡ß Row Attribute Register : Row00~14, Column30
F
E
D
C
B
-
BREN
INTE
CBli
A
BOXE BORD
9
8
7
6
5
4
3
2
1
0
SHA
RB
RG
RR
RINT
CINT
HZ1
HZ0
VZ1
VZ0
Raster Color
Intensity
Character Size
¡ß Frame Control Register 0 : Row15, Column00
F
E
-
Fde
D
C
B
FdeT VPOL HPOL
A
9
8
7
6
5
4
3
2
1
0
-
-
-
-
Erase
EN
ScrI
ScrT
Bli1
Bli0
BliT
¡ß Frame Control Register 1 : Row15, Column01
F
E
D
C
B
A
9
8
7
6
5
4
3
2
1
0
CP1
CP0
Fpll
HF2
HF1
HF0
dot1
dot0
-
FBLK
CH5
CH4
CH3
CH2
CH1
CH0
PLL Control
Character Height Control
¡ß Frame Control Register 2 : Row15, Column02
F
E
D
C
B
A
9
8
7
6
5
4
3
2
1
0
HP7
HP6
HP5
HP4
HP3
HP2
HP1
HP0
VP7
VP6
VP5
VP4
VP3
VP2
VP1
VP0
Horizontal Start Position
Vertical Start Position
14
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
Table 4. Register Description
Registers
Character & Attribute
Register (Row 00~14,
Column 00~29)
Bits
C7~C0
(Bit 7~0)
Blink/FINT
(Bit 9)
Description
Character Code Address of 256 ROM Fonts.
Character Blinking/Font Intensity Enable.
If I‘NTE’bit is low, this bit control blinking effect. The blinking period is
set by the 'BliT' bit and the duty is selected by the 'Bli0' and ' Bli1' bits.
If I‘NTE’bit is high, this bit control the font intensity combined with
I‘NTE’, R
‘ INT’and C
‘ INT’as following table.
INTE Blink/FINT RINT
CINT
Function
0
0
-
-
Normal
0
1
-
-
Blink
1
0
-
-
Normal(No Intensity)
1
1
0
1
Character Intensity
1
1
1
0
Raster Intensity
1
1
1
1
Character & Raster Intensity
B,G,R
(Bit C~A)
Character color is determined by these bits. 8 colors can be selected
and the color intensity of a character is given by 'CINT' bit of Row
Attribute Regisers. So user can select up to 16 colors.
BOX 1,
BOX0
(Bit E, D)
Character Box Drawing.
The combinations of this two bits generate four different box drawing
modes as following. The following example is the case that box
dawing is activated with the font 'A'
BOX0
0
1
BOX1
0
1
BOX OFF
A
A
A
* Bit F~D(RB/RG/RR) is also used for raster color by setting the
'BOXE' bit low. if the 'BOXE' bit is low,Raster color of a font is
determined by this bits . Priority of raster color selected here is
higher than that of row attribute.
BINV
(Bit F)
Box Inversion.
The box drawing activated by the bit E and D is changed to white
box from black and conversely.
15
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
Table 4. Register Description (Continued)
Registers
Bits
Description
Row Attribute Register
(Row 00 ~ 14, Column 30)
VZ1,VZ0
(Bit 1, 0)
Vertical Character Size Control. Vertical character size is determined
by the combinations of this two bits as following table.
HZ1,HZ0
(Bit 3, 2)
VZ1
VZ0
Vertical Character Size
0
0
1X
0
1
2X
1
0
3X
1
1
4X
Horizontal Character Size Control. The horizontal character size is
determined by the combinations of this two bits as following table.
HZ1
HZ0
Horizontal Character Size
0
0
1X
0
1
2X
1
0
3X
1
1
4X
CINT
(Bit 4)
Character Color Intensity. If I‘NTE’bit and this bit is set, the color
intensity of characters setting F
‘ INT’bit in the same row is high.
RINT
(Bit 5)
Raster Color Intensity. If I‘NTE’bit and this bit is set, the color
intensity of rasters setting F
‘ INT’bit in the same row is high.
RB,RG,RR
(Bit 8~6)
SHA
Raster Color is determined by these bits. 8 colors can be selected
and the color intensity of a character is given by R
‘ INT’bit of Row
Attribute Registers. So it can be selected up to 16 colors.
Character Shadowing. Set this bit to activate characters shadowing.
BORD
Character Bordering. Set this bit to activate characters shadowing.
BOXE
(Bit B)
BOX Enable. If this bit is set, Bit F-D in the Character & Attribute
Registers are used for the box-drawing function.
Otherwise,those are used for raster color of a font. Even though the
raster color attribute is given by Bit 8-6 in the row attribute registers,
the priority of Bit F-D in the character & attribute registers is higher.
CBli
(Bit C)
Color Blink Enable. If this bit is high, color blinking effect is activated.
The effect is to repeat color inversion between character and raster.
Color blinking time and the duty is controlled by Bil T, Bil 1 and Bli 0.
INTE
(Bit D)
Intensity Enable.
If this bit is set, the function of RINT and CINT bit are enabled and the
bit 9 of Character & Attribute Register control the font intensity effect.
Otherwise, all intensity functions are disabled and the bit 9 of Character & Attribute Register control the blinking effect.
BREN
(Bit E)
Back Raster Blank Enable.
If this bit is high and the raster color is black, the raster is transparent
Bit F
Reserved
16
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
Table 4. Register Description (Continued)
Registers
Frame Control Register 0
(Row 15, Column 00)
Bits
Bli T
(Bit 0)
Bli 1,Bli 0
(Bit 2,1)
Description
Blink Time Control.
If this bit is high, the blink time is 0.5 sec. Otherwise, 1 sec.
Blinking Duty Control.
The blinking duty is controlled by the combination of this two bits as
following.
Bli 1
Bli 0
Blinking Duty
0
0
Blink Off
0
1
Duty 25%
1
0
Duty 50%
1
1
Duty 75%
ScrT
(Bit 3)
Scroll Time Control.
If this bit is high, the scroll time is 0.5 sec. Otherwise, 1 sec.
Scrl
(Bit 4)
Scroll Enable.
The scroll display is activated by setting this bit high.
EN
(Bit 5)
OSD Enable.
If this bit is high, OSD is enable. Otherwise, disable.
Erase
(Bit 6)
RAM Erasing.
RAM data are erased by setting this bit.
Bit A ~ 7
Reserved.
HPOL
(Bit B)
Polarity of Horizontal Fly Back Signal. Positive 1, Negative 0
VPOL
(Bit C)
Polarity of Vertical Fly Back Signal. Positive 1, Negative 0
FdeT
(Bit D)
Fade-in and fade-out Time Control.
If this bit is high, the time is 0.5 sec. Otherwise, 1 sec.
Fde
(Bit E)
Fade-in and fade-out Enable.
The fade-in and fade-out effect is activated by setting this bit high.
Bit F
Reserved.
17
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
Table 4. Register Description (Continued)
Registers
Bits
Frame Control Register 1 CH 5~CH 0
(Row 15, Column 01)
(Bit 5~0)
FBLK
(Bit 6)
dot 1,dot 0
(Bit 9,8)
HF 2~HF 0
(Bit C~A)
FPLL
(Bit D)
CP 1,CP 0
(Bit F,E)
Description
Character Height Control. The vertical character size is determined
by the bit 'VZ1' and VZ0'. According to the value made by this six
bits, the character height is determined.
If the value is 32, the number of vertical pixel of character font is 32.
Eventually, the character height is expanded from 18 to 63.
The binary vlaue must be greater than 18.
It determines the configuration of FBLK output pin. When it is clear,
FBLK pin outputs high during displaying characters or rasters.
Otherwise,FBLK pin outputs high only during displaying characters.
This two bits determine the number of dots per horizontal line.
dot 1
dot 0
No. of Dots
0
0
320 dots/line
0
1
480 dots/line
1
0
640 dots/line
1
1
800 dots/line
The horizontal frequency information is transferred by this three bits.
HF2
HF1
HF0
Hf Information
0
0
0
15 KHz < Hf < 20 KHz
0
0
1
20 KHz ≤ Hf <35 KHz
0
1
0
35 KHz ≤ Hf < 50 KHz
0
1
1
50 KHz ≤ Hf < 65 KHz
1
0
0
65 KHz ≤ Hf <80 KHz
1
0
1
80 KHz ≤ Hf < 95 KHz
1
1
0
95 KHz ≤ Hf < 110 KHz
1
1
1
110 KHz ≤ Hf < 120 KHz
If this bit is high, the VCO block of OSD_PLL operates on full range
(4MHz - 96 MHz).
This bit controls charge pump output current.
CP 1
CP 0
Charge Pump Current
0
0
0.5mA
0
1
0.75mA
1
0
1.0mA
1
1
1.25mA
18
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
Table 4. Register Description (Continued)
Registers
Bits
Description
Frame Control Register 2 VP 7~VP 0
(Row 15, Column 02)
(Bit 7~0)
Vertical Start Position Control.
It means the top margin height from the V-sync reference edge.
( = VP[7:0] × 4 )
HP 7~HP 0
(Bit F~8)
Horizontal Start Position Control.
It means the horizontal display delay from the H-sync reference
edge to the 1'st pixel position of characters. ( = HP[7:0] × 6 )
19
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
STANDARD ROM FONTS
20
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
21
Preliminary
KS2508
OSD PROCESSOR FOR MONITOR
APPLICATION CIRCUIT
VCC=5V
+
100uF
104
1
392
5.6K
2
VSS_A
VDD_D
VCO_IN
INT
16
+
100uF
15
400
14
400
13
400
12
400
11
400
104
INT
101
R_OUT
36K
3
VREF1
R_OUT
VDD_A
G_OUT
100uF
+
G_OUT
Bead
1uH
104
4
4.7uF
5
KS2508
+
VREF
B_OUT
HFLB
FBLK
SDA
VSS_D
B_OUT
104
VCC
6
470
FBLK
VCC
HFLB
120
2K
2N3904
4.7K
7
10
4.7K
120 102
6.2K
2K
8
SCL
VFLB
9
120
1
SDA
2
SCL
VFLB
2.2nF
22