TV Remote Signal connection
In remote control televisions, microprocessors are often plugged in electrically erasable and writable, and are used to store tuning numbers. A color saturation, contrast, volume control data, and finally viewing TV stations. In order to achieve the microprocessor can be erasable erasable read and write. Memory to read and write operations and data between the CPU and EAR0M connection between the memory and the microprocessor must exist between the following connections.
(A) chip select signal connection
Computer and memory and other external devices using the bus bus connection, the device can only take up the bus, that is, time-sharing bus, the external device occupied by the CPU chip output chip select signal (CS) decision, when the CPU and memory phase When the chip select output (CS) is connected to the CS side of EAROM, the EAROM occupies the bus, the memory enters the working state, completes the operation command issued by the CPU,
(B) the connection of the clock signal
The clock signal is output from the clock output of the emblem processor and is sent to the clock signal input of the erasable erasable memory EAROM so that the microprocessor and the memory are synchronized by the same clock pulse to ensure that the two parts of the circuit work pace. Consistent. For example, the microprocessor sends the chip memory signal, the memory enters the working state, the microprocessor then sends out the data transmission signal. At the synchronization of the clock pulse, the memory is immediately in the working mode of the receiving data.
(C) memory operation mode control signal connection
Storage mode of operation control signal from the CPU output control signal, we are in the form of one-way transmission bus to draw, different memory, the mode of operation to control the signal line slightly different, such as M58655P electrically rewritable memory Integrated circuit, which has three control lines, it can be completed on the electric rewritable memory seven working state of the operation.
(C) the connection between the CPU and EAROM, cl c2 c3 1 5 8 氍 device status (d) the connection between the data line between the CPU and EAROM, cl c2 c3 1 5 8 device state need to connect the input, Output (I / 0 side) to wait line, read, I / 0 side of the CPU to the erase address input!) 9EAPOM I / 0 input address read LHH 9 data output LHL code, EAROM through I / 0 end to the data input, upper. CPU output The address unit is stored to write a 1-bit data write, CPU through i / 0 Figure 3 small 6 memory mode of operation control signal end to EAROM input Data and address codes, and store it in the specified storage unit. It is worth noting that writing data to EAROM requires a high voltage of one 30V write (the computer's operating voltage is typically 5V). Therefore, if the remote control color TV in a 3oV high voltage circuit failure, the resulting fault phenomenon should be related to the signal can not be stored, such as each time the TV must be set up a boot
Sound in the maximum state and so on. But some of the electrical can read and write memory write high voltage is generated by the 5V supply voltage through the internal voltage multiplier circuit. When the above fault occurs, only the memory integrated circuit is replaced when such memory is overhauled.