Philips 107B7 Manuale Utente

 

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The micro controller(IC101) core is a 80C51 type. The micro clock frequency of 12 Mhz is derived from the 

Xtal oscillator, which is running at 48MHz. The DDC interface is suitable to handle DDC2 by a    modified hardware 

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C-bus interface .Standard high current ports,3 ADC pouts with voltage inputs and 4 static standard 8 bit DAC 

outputs (low interference) and one PWM output for digital control application are implemented. The central 

processing unit (CPU) manipulates operands in two memory spaces. These are the 1024byte internal data 

memory(consisting of 256 bytes standard RAM and 768 bytes AUX-RAM) and 48K-byte internal program memory . 

The program memory of the SAA4849 consists of 48K bytes ROM. 

The SAA4849P provides sync. Processing with full auto sync. Capability, a flexible SMPS block and an 

extensive set of geometry control facilities. Further the IC generates the drive waveforms for DC coupled vertical 

boosters to the TDA4863A. 

 

 

The functions of the sync processor include polarity detection, H-SYNC & V-SYNC signals counting, 

Programmable SYNC signals output, free running signal generator. Pin52/Pin53 are for the H-SYNC and V-SYNC 

input.    and the polarity are setting in the positive. When no signal input, the Pin49 will output a 75Hz

 

V-SYNC free 

run signal. The Pin18/20will output a 60KHz H-SYNC free run signal. for the monitor testing use. 

 

There are three ways possible to invoke a reset and initialize the SAA4849 micro controller part: 

 

Via power-on reset circuit 

          Via watchdog timer overflow(only micro controller reset) 

                    Via deflection reset after start up(only micro controller reset) 

 

The reset pin(pin23) is connected to a Schmitt trigger for nose reduction. A reset is accomplished by holding the 

Reset pin HIGH. 

2.7K

R153

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22U

C145

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C102