Philips pca84c64 DATASHEETS

INTEGRATED CIRCUITS

DATA SH EET

PCA84C646; PCA84C846

Microcontrollers for TV tuning control and OSD applications

Preliminary speciﬁcation Supersedes data of June 1994 File under Integrated Circuits, IC14

1995 Jun 15

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

CONTENTS

1 FEATURES

1.1 PCF84CXXXA kernel

1.2 VST and OSD derivative 2 GENERAL DESCRIPTION 3 ORDERING INFORMATION 4 BLOCK DIAGRAM 5 PINNING INFORMATION

5.1 Pinning

5.2 Pin description 6 RESET

6.1 Reset trip level

6.2 Reset status 7 ANALOG CONTROL

7.1 6 and 7-bit PWM outputs (PWM00 to PWM07)

7.2 VST control 14-bit PWM DAC 8 AFC INPUT 9 OSD (ON SCREEN DISPLAY) FUNCTION

9.1 Features

9.2 Horizontal display position control

9.3 Vertical display position control

9.4 Clock generator 10 DISPLAY RAM ORGANIZATION

10.1 Description of display RAM codes

10.2 Loading character data into display RAM

10.3 Writing character data to display RAM

10.4 Default value of the display character 11 CHARACTER ROM

11.1 Character ROM organization

PCA84C646; PCA84C846

12 OSD CONTROL REGISTERS

12.1 Derivative Register 22 (CON1)

12.2 Derivative Register 23 (CON2)

12.3 Derivative Register 33 (CON3)

12.4 Derivative Register 34 (CON4)

12.5 Derivative Register 35 (VPOS)

12.6 Derivative Register 36 (HPOS)

12.7 Derivative Register 37 (BCC) 13 COMBINATION OF TWO OR MORE FONT

CELLS TO FORM A NEW FONT

14 OSD CLOCK IN DIFFERENT TV

STANDARDS

14.1 Maximum number of characters per row

14.2 Maximum number of rows per frame 15 T3: 8-BIT COUNTER 16 I2C-BUS MASTER SLAVE TRANSCEIVER 17 DERIVATIVE REGISTERS 18 INPUT/OUTPUT 19 OPTION LISTS 20 LIMITING VALUES 21 DC CHARACTERISTICS 22 AC CHARACTERISTICS 23 AFC CHARACTERISTICS 24 PACKAGE OUTLINE 25 SOLDERING 26 DEFINITIONS 27 LIFE SUPPORT APPLICATIONS 28 PURCHASE OF PHILIPS I2C COMPONENTS

1995 Jun 15 2

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

1 FEATURES

1.1 PCF84CXXXA kernel

• 8-bit CPU, ROM, RAM, I/O and derivative logic in one package

• Over 80 instructions

• All instructions of 1 or 2 cycles

• Quasi-bidirectional standard I/O port lines (P0, P1)

• Configuration of I/O lines individually selected by mask

• External interrupt

• 2 direct testable inputs T0, T1

• 8-bit timer/event counter

• Single level vectored interrupt: external (INT),

counter/timer, I2C-bus and VSYNC

• Configuration of optimal on-chip oscillator transconductance by mask

• On-chip oscillator clock frequency: 1 to 10 MHz

• Power-on-reset and low-voltage detector

• Low standby voltage and current in Idle and Stop modes

• Single power supply: 4.5 to 5.5 V

• Operating temperature: −20 to +70 °C.

1.2 VST and OSD derivative

• 6 kbytes (PCA84C646) or 8 kbytes (PCA84C846) system ROM, 192 bytes system RAM

• A multi-master I

• One 14-bit PWM output for VST

• Three AFC inputs with 4-bit DAC and comparator

• Four 6-bit PWM and four 7-bit PWM outputs

(DACs for analog controls)

• Eight port lines with 10 mA LED drive (at ≤1.2 V) capability

INT/T0

C-bus interface

PCA84C646; PCA84C846

• Programmable active level polarities of

• Display RAM: 64 × 10-bit

• Display character fonts: 64 (62 customized + 2 special

reserved codes)

• Display starting position: 64 different positions by software control, both vertical and horizontal

• Character size: 4 different character sizes, line-by-line basis, 1 dot = 1H/1V, 2H/2V, 3H/3V, 4H/4V. (H: OSD clock period, V: number of horizontal scan line height)

• Character matrix: 12 × 18 with no spacing between characters

• Foreground colours: 8, character-by-character basis

• Background colours: 8, word-by-word basis. Available

when background is either in North-west shadowing, Box shadowing and Frame shadowing mode

• Background/shadowing modes: 4, No background, North-west shadowing, Box shadowing, Frame shadowing (raster blanking), frame basis

• On-chip oscillator for On Screen Display (OSD) function

• Character blinking rate: 1 : 1, 1 : 3, 3 : 1 (frequency:

⁄16,1⁄32,1⁄64 or1⁄

character basis

• Display format: flexible display format by using Carriage Return (CR) code

• Spacing between lines: 4 different choices, from 0, 4, 8 or 12 horizontal scan lines

• Auto display character RAM address post increment when writing data

• On-chip Power-on-reset

• VSYNC leading edge can generate interrupt

(programmable enable/disable by software)

• 8-bit counter triggered by external pulse input.

128

of f

, programmable),

VSYNC

VSYNC/HSYNC

1995 Jun 15 3

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

2 GENERAL DESCRIPTION

The PCA84C646 and PCA84C846 are 8-bit microcontrollers with enhanced OSD and VST functions. The PCA84C646 and PCA84C846 are members of the PCA84C640 CMOS microcontroller family. They include the PCF84CXXXA processor core, 6 or 8 kbytes of ROM and 192 bytes of RAM.

I/O requirements are adequately catered for with 13 general purpose bidirectional I/O lines plus 16 function combined I/O lines. One 14-bit PWM analog control, 3 AFC inputs (4-bit DAC + comparator) for VST and four 6-bit and 7-bit PWM analog control outputs are provided.

3 ORDERING INFORMATION

TYPE NUMBER

PCA84C646P PCA84C846P

NAME DESCRIPTION VERSION

SDIP42 plastic shrink dual in-line package; 42 leads (600 mil) SOT270-1

PCA84C646; PCA84C846

In addition to all these features a master-slave I interface, 2 directly testable lines and an enhanced OSD facility for flexible screen format (maximum of 64 character types) are also provided.

The on-chip Phase-Locked Loop (PLL) oscillator for OSD operation considerably reduces the radiation generated by the RC or LC oscillator. An 8-bit timer is integrated on-chip with a 5-bit prescaler. Another 8-bit counter with Schmitt-trigger input is used for clock/timer function application.

Figure 1 shows the block diagram of the PCA84C646 and PCA84C846.

PACKAGE

C-bus

1995 Jun 15 4

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

4 BLOCK DIAGRAM

HSYNC

VSYNC

VOW2

VOW1

VOW0

VOB

ON SCREEN DISPLAY

8-bit internal bus

I C-BUS

AFC

3 x 4-BIT

PCA84C646; PCA84C846

MED169

INTERFACE

DAC +

COMPARATOR

SDA SCL

AFC2

INT / T0 T3

RAM

192 bytes

(1)

(2)

ROM

6 kbytes or8 kbytes

8-BIT

COUNTER

CPU

8-BIT

EVENT

TIMER /

COUNTER

DAC

14-BIT

4 x 6-BIT PWM

4 x 7-BIT PWM

PCF84CXXXA

core excluding

ROM / RAM

I / O

PORTS

PARALLEL

48 4

8-BIT I/O PORTS

TDAC AFC0

DP20toDP23

DP10toDP13

DP00/PWM00

DP07/PWM07

P14

P10 to P12

P00toP07

Fig.1 Block diagram

handbook, full pagewidth

1995 Jun 15 5

XTAL1 (IN)

XTAL2 (OUT)

RESET

TEST / EMU

ROM size:

(1) 6 kbytes for PCA84C646.

(2) 8 kbytes for PCA84C846.

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

5 PINNING INFORMATION

5.1 Pinning

handbook, halfpage

DP22/VOW1 DP23/VOW0

VOB

VOW2

VSYNC

HSYNC

P10/DXWR

P11/DXRD

DP13/TDAC

P12/DXALE

P14/DXINT

P00 P01 P02 P03

1 2 3 4 5 6 7 8 9

PCA84C646

PCA84C846

12 13 14 15

42 41

DP20/SDA

DP21/SCL DP10/AFC0

38 37

DP11/AFC1 DP12/AFC2

36 35

INT/T0

RESET

XTAL2

XTAL1 TEST/EMU

30 29

DP00/PWM00

DP01/PWM01 DP02/PWM02

PCA84C646; PCA84C846

P04

P05

P06

P07

Fig.2 Pin configuration PCA84C646P and PCA84C846P (SDIP42; SOT270-1).

1995 Jun 15 6

MED171

DP03/PWM03

DP04/PWM04

DP05/PWM05

DP06/PWM06

DP07/PWM07

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning

PCA84C646; PCA84C846

control and OSD applications

5.2 Pin description Table 1 Pin description for PCA84C646P and PCA84C846P; SDIP42 (see Fig.2)

SYMBOL PIN DESCRIPTION

VOB 1 Video fast blanking output signal. VOW2 2 Video character outputs or derivative port lines. DP22/VOW1 3 DP23/VOW0 4 VSYNC 5 Vertical synchronization signal input, active LOW. HSYNC 6 Horizontal synchronization signal input, active LOW.

DXWR 7 Port line 10 or emulation DXWR signal input.

P10/

DXRD 8 Port line 11 or emulation DXRD signal input.

P11/ DP13/TDAC 9 Derivative I/O port or 14-bit D/A PWM. P12/DXALE 10 Port line 12 or emulation DXALE signal input. T3 11 Secondary 8-bit counter input pin (Schmitt-trigger). P14/DXINT 12 Port line 14 or emulation DXINT signal input. P00 to P07 13 to 20 General I/O port lines (10 mA). V

DP00/PWM00 to DP07/PWM07 29, 28, 27, 26,

TEST/EMU 30 Control input of testing and emulation mode, normally LOW. XTAL1 31 Oscillator input terminal for system clock. XTAL2 32 Oscillator output terminal for system clock. RESET 33 Initialize input, active LOW. T1 34 Direct testable pin and event counter input. INT/T0 35 External interrupt/direct testable pin. DP12/AFC2 36 Derivative I/O port or comparator input with 4-bit DAC. DP11/AFC1 37 DP10/AFC0 38 DP21/SCL 39 Derivative port line or I DP20/SDA 40 Derivative port line or I C 41 External capacitor input for on chip PLL OSD oscillator. V

21 Ground.

Derivative I/O port;

25, 24, 23, 22

42 Power supply.

6-bit PWM (PWM04 to 07) or 7-bit PWM (PWM00 to 03).

C-bus clock line.

C-bus data line.

1995 Jun 15 7

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

6 RESET

The RESET pin is used as an active LOW input to initialize the microcontroller to a defined state.

A Power-on-reset can be generated by using the RC-circuit as shown in Fig.3.

An active reset can be generated by driving theRESET pin from an external logic device. Such an active reset pulse should not fall off before VDD has reached its f

-dependent minimum operating voltage.

xtal

6.1 Reset trip level

RESET trip-voltage level is masked to 1.3 V in the

The PCA84C646 and PCA84C846.

6.2 Reset status

• Derivative Registers status; for details see Table 40

• Program Counter: 00H

• Memory Bank: 00H

• Register Bank: 00H

• Stack Pointer: 00H

• All interrupts disabled

• Timer/event counter 1 stopped and cleared

• Timer prescaler modulo-32 (PS = 0)

• Timer flag cleared

• Serial I/O interface disabled (ESO = 0) and in slave

receiver mode

• Idle and Stop mode cleared.

PCA84C646; PCA84C846

7 ANALOG CONTROL

7.1 6 and 7-bit PWM outputs (PWM00 to PWM07)

The PCA84C646/PCA84C846 has eight PWM outputs for analog controls of e.g. volume, balance, brightness and saturation. These PWM outputs generate pulse patterns with a repetition rate of analog value is determined by the ratio of the HIGH-time and the repetition time. A DC voltage proportional to the PWM control setting is obtained by means of an external integration network (low-pass filter).

The eight PWM outputs are specified as follows:

• PWM00 to PWM03 outputs with 7-bit resolution

• PWM04 to PWM07 outputs with 6-bit resolution.

Figure 4 shows the block diagram of the 6-bit or 7-bit PWM DAC. The polarity of the PWM0n output is selected as shown in Table 2 by the polarity control bit P6LVL/P7LVL (Derivative Register 23; see Table 25).

The PWM0n output shares the pin with a DP0n I/O line under control of a PWMnE enable bit; for selection see Table 3.

Figure 5 shows the 6 and 7-bit PWM0n output patterns (non-inverted; P6LVL/P7LVL = 0).

The HIGH-time of a PWM0n output is t

= [PWMnDL]×t

HIGH

where:

[PWMnDL] = the contents of PWMn data latch (n = 0 to 7; Derivative Register 10 to 17; see Table 40)

t0= 1/f

PWM

; f

PWM

⁄64× f

=1⁄3× f

xtal

PWM

or1⁄

128

× f

PWM

. The

RESET

( 100 kΩ)

RESET

(1) To avoid overload of the internal diode, an external

diode should be added in parallel if C

Fig.3 External components for RESET pin.

1995 Jun 15 8

Table 2 Polarity selection for the PWM0n output

P6L VL/P7LVL POLARITY

(1)

internal reset

1 inverted 0 not inverted

Table 3 Selection of pin function: DP0n/PWM0n (note 1)

PWMnE FUNCTION

PCA84C646/846

MED172

1 PWM0n output 0 DP0n I/O

Note

RESET

> 0.2 µF.

1. n = 0 to 7.

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

handbook, full pagewidth

PWM =

xtal

6 or 7-BIT PWM DATA LATCH

6 or 7-BIT DAC PWM

CONTROLLER

P6LVL/P7LVL

(1-BIT)

PCA84C646; PCA84C846

DP0n data

I/O

PWMnE

DP0n/PWM0n

MED177

handbook, full pagewidth

xtal

64 or

128

63

or

127

Fig.4 Block diagram of 6-bit or7-bit PWM DAC.

1 2 3 m m + 1 m + 2

decimal value PWM data latch

64

or

128

MLC261

1995 Jun 15 9

Fig.5 Example PWM0n output patterns (P6LVL/P7LVL = 0).

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

7.2 VST control 14-bit PWM DAC

The PCA84C646 and PCA84C846 have a PWM DAC output (TDAC) with a resolution of 16384 levels for Voltage Synthesized Tuning (VST).

Figure 6 shows the block diagram of the 14-bit PWM DAC which consists of:

• Two 7-bit DAC interface latches (see Table 40): – VSTH: Derivative Register 18; address 18H. – VSTL: Derivative Register 19; address 19H.

• One 14-bit DAC data latch: VSTREG, which contents defines the HIGH-time.

• 14-bit counter.

• Pulse control.

The contents of the interface latches VSTH and VSTL are latched into VSTREG. The upper seven bits of VSTREG are used for coarse adjustment, while the lower seven bits are used for fine adjustment.

The contents of the interface latches VSTH and VSTL are latched into VSTREG at the beginning of the first t VSTL is written (see Fig.7). After VSTH and VSTL are latched into VSTREG, it takes one t

to generate the

sub

appropriate pulse pattern. Therefore, to ensure correct digital-to-analog conversion,

two t

periods should be allowed before beginning the

sub

next sequence (changing the contents of VSTH and VSTL).

To ensure that the correct data is latched into VSTREG, VSTH must contain the correct value before VSTL is written; see the note in Fig.7.

The repetition times of the pulse controllers are:

• Coarse, upper seven bits (VSTH):

sub

128 3 f

⁄×=

xtal

• Fine, lower seven bits (VSTL):

128 t

× 49152 f

sub

⁄==

xtal

Output TDAC shares the same pin as DP13; bit TDACE (Derivative Register 22; see Table 22) selects the function of pin DP13/TDAC.

Table 4 Selection of pin function DP13/TDAC

TDACE FUNCTION

1 TDAC; 14-bit PWM output 0 DP13

sub

after

PCA84C646; PCA84C846

7.2.1 C An active HIGH pulse is generated in every subperiod; the

pulse width being determined by the contents of VSTH. The coarse output (OUT1) is LOW at the start of each subperiod and will remain LOW during

≤

Where ts is the time within t The output will then go HIGH and remain HIGH until the

start of the next subperiod. The coarse pulse width may be calculated as: .

7.2.2 F Fine adjustment is achieved by generating an additional

pulse in specific subperiods. The pulse is added at the start of the selected subperiod and has a pulse width of 3/f

xtal

subperiods a fine pulse will be added. It is the logic 0 state of the value held in VSTL that actually selects the subperiods. When more than one bit is a logic 0 then the subperiods selected will be a combination of those subperiods specified in Table 5. For example, if VSTL = 111 1010 then this is a combination of:

• VSTL = 111 1110: subperiod 64 and

• VSTL = 111 1011: subperiods 16, 48, 80 and 112.

Pulses will be added in subperiods 16, 48, 64, 80 and 112. This example is illustrated in Fig.9.

When VSTL holds 111 1111 fine adjustment is inhibited and the TDAC output is determined only by the contents of VSTH.

Table 5 Additional pulse distribution

111 1110 64 111 1101 32 and 96 111 1011 16, 48, 80 and 112 111 0111 8, 24, 40, 56, 72, 88, 104 and 120 110 1111 4, 12, 20, 28, 36, 44, 52...116 and 124 101 1111 2, 6, 10, 14, 18, 22, 26, 30...122 and 126 011 1111 1, 3, 5, 7, 9, 11, 13, 15, 17...125 and 127

OARSE ADJUSTMENT

VSTH 1+()3×

------------------------------------------f

xtal

subn

Pulse duration 127 VSTH–()

INE ADJUSTMENT

×=

-------f

xtal

. The contents of VSTL determine in which

VSTL ADDITIONAL PULSE IN SUBPERIOD

1995 Jun 15 10

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

‘MOVE instruction’

DAC INTERFACE

7-BIT DATA LATCH

(VSTH)

DATA LOAD

TIMING PULSE

Internal data bus

MSB LSB

DAC INTERFACE

7-BIT DATA LATCH

LOAD

(1)

COARSE 7-BIT

14-BIT DATA LATCH

(VSTREG)

7 7

PWM

OUT2OUT1

PCA84C646; PCA84C846

‘MOV instruction’

(VSTL)

FINE

ADDITIONAL

PULSE

GENERATOR

(1) See Fig.7 for timing.

PWM output polarity control bit

P14LVL

ADD

Q14 to 8 Q7 to 1

14-BIT COUNTER

MED179

Fig.6 Block diagram of the 14-bit PWM DAC.

TDAC output

f = f

TDAC xtal

1995 Jun 15 11

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

CASE 1

CASE 2

CASE 3

sub

VSTH VSTL

sub

VSTL

VSTH VSTL

sub

VSTH,VSTL is loaded into VSTREG

sub

VSTH,VSTL is loaded VSTH into VSTREG

PCA84C646; PCA84C846

sub

VSTH,VSTL is loaded into VSTREG

sub

MED180

In CASE 1 and CASE 2, a new value for VSTH, VSTL is latched into VSTREG. In CASE 3, VSTL, together with an old value of VSTH are latched into VSTREG.

Fig.7 Latching VSTH, VSTL into VSTREG.

handbook, full pagewidth

xtal

127 m m + 2

127

decimal value VSTH data latch

3/f

xtal

(1)

2 m + 1

(1)

subn

127 1

(1)

MGC573

(1) t

-------------------------------------------

xtal

VSTH 1+()3×

Fig.8 TDAC output (not inverted) with coarse adjustment only; VSTL = 1111111; P14LVL = 0.

1995 Jun 15 12

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

handbook, full pagewidth

111 1110

111 1101

111 1011

111 1010

VSTL

sub0

sub16

sub32

sub48

sub64

PCA84C646; PCA84C846

sub80

sub96

sub112

sub127

MCD314

handbook, full pagewidth

xtal

127 m

127

3/f

xtal

decimal value VSTH data latch

Fig.9 Fine adjustment output (OUT2).

sub16

m + 1

m + 2

127 1

MGC572

VSTL = 111 1010; Additional pulses in subperiods 16, 48, 64, 80 and 112.

Fig.10 Example of TDAC (not inverted) output pulses for several values of VSTH (t

1995 Jun 15 13

sub16

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

8 AFC INPUT

The AFC input is intended to measure the level of the Automatic Frequency Control (AFC) signal. This is done by comparing the AFC signal with the output of a 4-bit digital-to-analog converter as shown in Fig.11. The DAC analog switches select one of the 16 resistor taps that are connected between VDD and VSS (controlled by bits AFCV3, AFCV2, AFCV1, AFCV0; Derivative Register 20). The AFCC signal (bit 0 in Derivative Register 20) then can be tested to check whether the AFC input is higher or lower than the DAC level.

The AFC inputs AFC0, AFC1 and AFC2 share the same pins as Derivative Port lines DP10, DP11 and DP12. The pin functions are selected by bits AFCE0, AFCE1, AFCE2 (AFC enable/disable bits; Derivative Register 22); for selection see Table 6.

AFCH1 and AFCH0 (Derivative Register 20) select one out of three AFC inputs to the comparator; for a correct comparison, enable the corresponding AFC input (AFCi) as shown in Table 7.

The conversion time of the AFC is greater than 6 µs but less than 9 µs. It is recommended to add a NOP instruction between the instruction which changes V selection and the instruction which reads the AFCC bit (compare bit).

or channel

ref

PCA84C646; PCA84C846

If the compare bit:

• AFCC = 0, then the AFC voltage < V

• AFCC = 1, then the AFC voltage > V

Table 6 Selection of pin function DP1i/AFCi (i = 0, 1, 2)

BIT VALUE PIN FUNCTION COMPARATOR

AFCE2 1 DP12 disabled

0 AFC2 enabled

AFCE1 1 DP11 disabled

0 AFC1 enabled

AFCE0 1 DP10 disabled

0 AFC0 enabled

Table 7 AFC input selection

AFCH1 AFCH0 SELECT

0 0 AFC Channel 0; AFC0 0 1 AFC Channel 1; AFC1 1 0 AFC Channel 2; AFC2 1 1 reserved

ref ref

. .

handbook, full pagewidth

DP10/AFC0

AFC

DP11/AFC1

DP12/AFC2

Channel selection

AFCE0 AFCE1 AFCE2

ANALOG

SELECTOR

AFCH1 AFCH0

AFC function enable

selection

ENABLE

SELECTOR

Fig.11 AFC circuit.

1995 Jun 15 14

AFCV3

(DP10 to DP12)

EN1 EN2EN0

COMPARATOR

4-BIT D/A

AFCV2 AFCV1 AFCV0

AFC value selection

Internal bus

‘MOV A, D20’

instruction

to read AFCCx bit

MED185

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

Table 8 V

AFCV3 AFCV2 AFCV1 AFCV0 V

0000 V 0001 V 0010 V 0011 V 0100 V 0101 V 0110 V 0111 V 1000 V 1001 V 1010 V 1011 V 1100 V 1101 V 1110 V 1111 V

as a function of AFCV3 to AFCV0

ref

DD DD DD DD DD DD DD DD

DD DD DD DD DD DD DD

ref

×1⁄ ×2⁄ ×3⁄ ×4⁄ ×5⁄ ×6⁄ ×7⁄ ×8⁄

×9⁄ ×10⁄ ×11⁄ ×12⁄ ×13⁄ ×14⁄ ×15⁄

PCA84C646; PCA84C846

(VDD= 5.0 V)

ref

16 16 16 16 16 16 16 16 16

16 16 16 16 16 16

0.31 V

0.62 V

0.93 V

1.25 V

1.56 V

1.87 V

2.18 V

2.50 V

2.81 V

3.12 V

3.43 V

3.75 V

4.06 V

4.37 V

4.68 V

5.00 V

1995 Jun 15 15

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

9 OSD (ON SCREEN DISPLAY) FUNCTION

9.1 Features

• Display RAM: 64 × 10 bit.

• Display character fonts: 64 (in which 62 customized +

2 special reserved codes).

• Display starting position (of the first character): 64 different positions by software control, both vertical and horizontal.

• Character size: 4 different character sizes, line-by-line basis, 1 dot = 1H/1V, 2H/2V, 3H/3V, 4H/4V.

• Character matrix: 12 × 18 with no spacing between characters.

• Foreground colours: 8, combination of Red, Green, Blue; character-by-character basis.

• Background/shadowing modes: 4, No background, Box shadowing, North-west shadowing, Frame shadowing (raster blanking), frame basis.

• Background colours: 8, combination of Red, Green, Blue; word-by-word basis. Available when background mode is either in Box shadowing or North-west shadowing and Frame shadowing mode.

• On-chip OSD oscillator.

• Character blinking rate: 1 : 1, 1 : 3, 3 : 1 (frequency:

⁄16,1⁄32,1⁄64 or1⁄

e.g. NTSC:60⁄16Hz, PAL:50⁄64Hz etc.); character basis.

• Display format: flexible display format by using Carriage Return (CR) code, maximum number of characters per line is flexible and depending on the OSD clock.

• Spacing between lines: 4 different choices from 0, 4, 8 or 12 horizontal scan lines.

• Display character RAM auto-address-post-increment when writing data.

• Programmable HSYNC and VSYNC active input polarity.

• Programmable G (VOW1), B (VOW2), R (VOW0) and

FB (VOB) output polarity.

9.2 Horizontal display position control

The horizontal position counter is increased every OSD clock (f

) cycle after the programmed level of HSYNC

OSD

occurs at the HSYNC pin and is reset when the opposite polarity of the HSYNC is reached. Horizontal start position is controlled by Derivative Register 36 (HPOS; see Table 36). The starting position is calculated as:

HP = [4 × (H5 to H0) + 5] × (OSD clock cycle) where (H5 to H0) = decimal value of register HPOS;

(H5 to H0) ≥ 10.

128

of f

, programmable,

VSYNC

PCA84C646; PCA84C846

9.3 Vertical display position control

The vertical position counter is increased every HSYNC cycle and is reset by the VSYNC signal. Vertical start position is controlled by Derivative Register 35 (VPOS; see Table 34). The vertical starting position is calculated as:

VP = [4 × (V5 to V0)] × (horizontal scan lines) where (V5 to V0) = decimal value of register VPOS;

(V5 to V0) ≥ 0.

9.4 Clock generator

Figure 12 illustrates the block diagram of the on-chip OSD clock generator which consists of a Phased-Lock Loop (PLL) circuit. The Voltage Controlled Oscillator (VCO) outputs a clock (f 8 to 20 MHz (see Fig.12). The input signal f1= HSYNC.

The programmable active level detector:

• Passes signal f1, when HSYNC is active HIGH, or

• Inverts signal f1, when HSYNC is active LOW.

The output signal f2 is always active HIGH. The VCO is synchronized with the HIGH-to-LOW edge of the f2 signal.

The value programmed in the 7-bit PLL Programmable Counter control register (PLLCN; Derivative Register 25; see Table 40) determines:

VCO=f1

×16 × (decimal value of 7-bit counter);

where 16< (decimal value of 7-bit counter) < 48.

The value 16 is the 4-bit prescaler which increases or decreases the output of the VCO in steps of (16 × f1). Given an example of f1= 15.750 kHz, the f increased or decreased in steps of 16 × 15.750 kHz = 252 kHz = 0.25 MHz.

The f

is fed into a buffer to generate the OSD dot clock

VCO

frequency signal (f Decreasing f

OSD

Recommended: 4 MHz ≤ f The OSD clock is enabled/disabled by the state of the EN

bit (Derivative Register 34; see also Section 12.4). When the OSD clock is disabled (f remains active, therefore the transient time from the OSD clock start-up to locking into the external HSYNC signal is reduced.

As the on-chip oscillator is always active after Power-on, when the OSD clock is enabled no large currents flow (as for RC or LC oscillators) and therefore radiated noise is dramatically reduced.

) with a frequency range of

VCO

); 4 MHz ≤ f

OSD

≤ 12 MHz.

gives broader characters.

typical ≤ 12 MHz.

OSD

= LOW) the oscillator

OSD

VCO

is then

1995 Jun 15 16

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

9.4.1 MOUNTING PRECAUTIONS

To achieve good OSD performance, take the following precautions for the microcontroller mounting:

• Apply the recommended R, Cs and Cp (PLL loop filter) values as shown in Fig.12 and place them as close as possible to pin C (41).

• To guarantee stable PLL operation, apply a noise-free HSYNC signal (pin 6).

• Avoid heavy loading of the output pins.

• The supply voltage (VDD) must be correctly decoupled.

Connect decoupling capacitors as close as possible to the VDD and VSS pins.

handbook, full pagewidth

HSYNC

ACTIVE

LEVEL

DETECTOR

FREQUENCY

(2)

PROGRAMMABLE

STANDBY

PHASE/

DETECTOR

divided by N

7-BIT COUNTER



PCA84C646; PCA84C846

• Position microcontroller optimal and away from components bearing high voltage and/or strong current.

• PLL loop filter ground of capacitors C directly connected to the VSS pin (21). Avoid a ground loop and separate the ground from other digital signals ground.

• The connection between VSS pin (21) and +5 V regulator ground/switching power supply secondary ground must be as short as possible.

CHARGE PUMP

AND

LOOP FILTER

VCO

VOLTAGE

CONTROLLED

OSCILLATOR

and Cp must be

(1)



OSD

(OSD clock)

(1) R=10to47kΩ; typ. 15 kΩ.

= 100 to 470 nF; typ. 220 nF.

=1⁄10Cs.

For mounting see Section 9.4.1 “Mounting precautions”.

(2) Example:

= 15.750 kHz and (decimal value of 7-bit counter) = 32 then f

If f

and the output of the Programmable 7-bit counter is 15.750 kHz.

VCO

Fig.12 On-chip OSD oscillator.

1995 Jun 15 17

= 8.064 MHz

OSD disable

MED196

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

CONTROL

RAM

DISPLAY

CHARACTER

BUFFER

ADDRESS

SELECTOR

BIT

DISPLAY

PATTERN

DISPLAY CONTROL

ROM(64)

control

signals

PCA84C646; PCA84C846

MED189

AND

OUTPUT STAGE

RGBFB

VOW1 VOW0 VOW2 VOB

CPU bus

COUNTER

WRITE ADDRESS

POSITION

HORIZONTAL

CONTROL

CHARACTER SIZE

POSITION

VERTICAL

COUNTER

ON-CHIP

COUNTER

CONTROL REGISTER

INSTRUCTION DECODER

OSCILLATOR

CIRCUIT

INTERNAL

SYNCHRONOUS

handbook, full pagewidth

Fig.13 OSD block diagram.

1995 Jun 15 18

HSYNC

VSYNC

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning

PCA84C646; PCA84C846

control and OSD applications

10 DISPLAY RAM ORGANIZATION

The display RAM is organized as 64 × 10 bits. The general format of each RAM location is as follows:

• Bits <9-4> hold data, comprising: – Customer designed Character Font Codes (62) – Carriage Return Code (1) – Space Code (1).

• Bits <3-0> contain the attributes of the Character Font: – Foreground colour and Blinking – Character size and Line space – Background colour and End-of-Display .

Table 9 Format of Character Font Code

987654321 0

C5 C4 C3 C2 C1 C0 T3 T2 T1 T0

Character Font Code (00H - 3DH) Foreground colour Blink

10.1 Description of display RAM codes

There are three data formats for the display RAM code

1. Character Font Code

2. Carriage Return Code

3. Space Code. The three data formats and their descriptions are shown in

Tables 9 to 17. Figure 14 illustrates an example of the timing of FB, R, G, and B pulses when displaying a line of dots stream in a character. FB = VOB; R = VOW0, G = VOW1; B = VOW2.

Figure 15 shows an example of the screen which includes some Cariage Return and Space codes.

Table 10 Description of Character Font Code bits

SYMBOL DESCRIPTION

C5 to C0 If bits <9-4> are in the range (00H to 3DH), then this is a Character Font Code and 1 from 62 customer

designed character fonts can be selected. T3 to T1 Bits <3-1> determine the (Foreground) colour (1 out of 8) of this character; see Table 11. T0 Blinking of this character is controlled by bit <0>. See Section 12.3 for duty cycle and frequency control.

When T0 = 0; blinking is OFF. When T0 = 1; blinking is ON. Blinking rate:

Table 11 Selection of Background and Foreground colour

(RED)

0 0 0 black 0 0 1 blue 0 1 0 green 0 1 1 cyan 100red 1 0 1 magenta 1 1 0 yellow 1 1 1 white

(GREEN)

⁄16,1⁄

⁄64or1⁄

128

(BLUE)

× f

VSYNC

COLOUR

1995 Jun 15 19

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning

PCA84C646; PCA84C846

control and OSD applications

Table 12 Format of Carriage Return Code

9876543210

C5 C4 C3 C2 C1 C0 T3 T2 T1 T0

Carriage Return Code (3EH) Character size Line Spacing

Table 13 Description of Carriage Return Code bits; format is shown in Table 12

SYMBOL DESCRIPTION

C5 to C0 If bits <9-4> hold 3EH, then this is the Carriage Return Code. The current display line is terminated

(a transparent pattern appears on the screen) and the next character will be displayed at the beginning of

the next line. T3 to T2 Bits <3-2> select the size of the of the character to be displayed on the next line; see Table 14. T1 to T0 Bits <1-0> determine the spacing between lines of displayed characters. Spacing is a multiple of the

number of horizontal scan lines. In order to prevent vertical jumping of the display, the first line should be

a non-displayed line i.e. the Carriage Return Code.

The line spacing for this code must not be zero; see Table 15.

Table 14 Selection of character size

T3 T2 CHARACTER DOT SIZE

0 0 1H/1V 0 1 2H/2V 1 0 3H/3V 1 1 4H/4V

(1)

Table 15 Selection of line spacing

T1 T0 LINE SPACING

0 0 0H line 0 1 4H line 1 0 8H line 1 1 12H line

Note

1. H is the OSD clock period; V is the number of horizontal scan lines per dot.

Table 16 Format of Space Code

987654321 0

C5 C4 C3 C2 C1 C0 T3 T2 T1 T0

Space Code (3FH) Background colour End

Table 17 Description of Space Code bits; format is shown in Table 16

SYMBOL DESCRIPTION

C5 to C0 If bits <9-4> hold 3FH, then this is the Space Code. A transparent pattern, equal to one character width,

will be displayed on the screen.

T3 to T1 Bits <3-1> determine the background colour of the characters including the Space Code in Box

shadowing mode but following the Space Code in North-west shadowing mode. See Section 12.4 for more details. Background colour selection is the same as Foreground colour selection; see Table 11.

T0 Bit <0> is the End-of-Display bit and indicates the end of display of the current screen before exhaustion

of display RAM. The last character displayed on the TV screen is either the 64 Code with the End-of-display attribute set to logic 1.

When T0 = 0; continue display of next character. When T0 = 1; end of display.

RAM location or a Space

1995 Jun 15 20

Philips Semiconductors Preliminary speciﬁcation

Microcontrollers for TV tuning control and OSD applications

handbook, full pagewidth

R G B

ACM

"S" : red colour "E" : B+I colour "I" : green colour 1st SP code : ACM = on "Z" : G+B+I colour 2nd SP code : ACM = off

PCA84C646; PCA84C846

SP code SP code

MED204

handbook, full pagewidth

line spacing 1 = 4H

line spacing 2 = 8H

Fig.14 R, G, B and FB timing.

Vstart

HI ! THIS ISSP SP CR

T H E N E W F U N C I O NT I N P C F 8 5 C X X

Hstart

St andal

Volume

Four different background colours (in box shadowing mode):

Channel

Black

Red

Green Blue

E L C O M EW

line spacing 3 = 0H line spacing 4 = 0H

line spacing 4 = 4H

line spacing 6 = 0H

MED205

1995 Jun 15 21

Fig.15 On-screen-display (an example).

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