BOOT UP SEQUENCE
Bootup on the microcontroller, there are two types of boot up the hardware and boot up the software. Stages of boot up the hardware as follows:
1. IC start the bootup program if given the working voltage has been included in the normal working voltage range.
2. Crystal oscillator contained in the start oscillating. Crystal oscillator function is to provide a pulse / clock on the microcontroller.
3. Once there is a clock, the IC program to check and set the hardware / internal registers with default values. Then the IC program wait reset via RESET pin.
4. This reset process, done manually or automatically by external devices. In general, the TV using the IC Reset to reset the program. Example reset IC is KIA70 (on tv LG / Goldstar).
5. After receiving a reset signal, the IC program began to run / execute software that is installed / programmed before (start the boot-up software).
While the stages of boot up the software depends on the sequences of statements or statement-programmed software. Because the software boots up sequence variations are many and vary from each programmer, the authors reviewed only the general course.
In general, the order of the boot-up software IC TV programs which are all based on the program / programmer based on the desire, the order is as follows:
1. IC program set all the registers / internal equipment with default values / standards.
2. Reading data from memory and then disetkan on registers / ports.
3. Doing the power on to the unit / TV.
4. Conducting monitoring stages of the operation. For example, protection system, hangs and others.
5. Finally, monitoring of events / responses to the effects of the use (buttons / keyboard, remote etc).
Troubleshooting
Before performing troubleshooting, a few things to know and important to the operation of the IC program are:
1. CLOCK, clock is a pulse / pulse that serves as the heartbeat processor. Width / long pulse depends on the frequency of the crystal and programs that have been programmed.
2. IC RESET, reset IC is a way of working as a voltage detector, which detects the voltage VDD ic program. If the voltage VDD has reached the threshold reset, it will send a pulse ic reset (the goal to reset the program).
3. INTERRUPTION, is a service provided by the processor to listen to the response of the user / other equipment. As processors get an interrupt, the processor will run the sub routine / specific programs depending on the type interupsinya. For example, pin / IR port, if any incoming IR signal and the signal is known by the program, the program will run a subroutine that has been programmed. Status/kejadian2 keyboard when there is a push button and others.
4. Type of input or output ports. PWM / ADC input pins normally used for AFT, PWM / DAC output is used untukvolume, contrast, color, hue, and others. IO pin logic used for setting options, reset, tv / av, switching, video ident and others.
Because of the troubleshooting process depends on the type and form of the circuit, so here only the general procedures are reviewed. Troubleshooting procedures / search program IC damage is (hardware):
1. Check all ports if konslet foot of VSS / ground or not. Measurement with 1K ohm meter on the meter. Please note type of pin / port. In general, the barriers are normally as follows: PWM input / ADC of about 1 to 3K, PWM output is approximately 1 to 5K and IO logic around 5K. If found less than that value, the possibility of a short-circuit the pins are tested.
2. Having not found konslet, check the input components such as switches and IR receiver.
Troubleshooting can be found after learning the characteristics of a normal IC program. The characteristics of a normal IC program are:
1. The existence of a clock, characterized by the voltage swing on pins SDA / SCL (if using multitester needle). If using memory ic 24Cxx pins SDA and SCL in pin5 on pin6.
2. The appearance of OSD screen, if the screen does not appear, check the path H SYNC, V SYNC, BLK and OSD oscillator.
3. IC program to operate normally. No excessive heat.
4. In general if dikonsletkan reset pin to ground for a moment, the TV will standby and do the reset again.
IC program cranky, often caused by:
1. Voltage ripple is unstable or there.
2. Switch / IR in the circumstances then pressed, causing interruptions in a state program ic (continued execution of the program if the interruption had been released).
3. Bus error, check the pins SDA / SCL.
4. Interference on the ports in input / output. The ports are experiencing hold / on hold.
5. Software that is installed is corrupt / damaged = IC programs should be replaced.
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