JPH0374048B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a channel selection device used in a television receiver, and particularly to a channel selection device using a nonvolatile memory.

Conventionally, in channel selection devices using non-volatile memory, the power supply for writing and reading data in the memory is
A high negative voltage is required, and as this negative power source, a method is widely used in which the negative power source is taken out from the secondary winding of the FBT (flyback transformer) of the television receiver, which is advantageous in terms of cost.

In particular, in a channel selection device with a built-in remote control, it is necessary to constantly supply power in order to operate the remote control, but the power supply for the memory cannot obtain voltage because the power of the television receiver or the like is off. Therefore, in order to read data from the nonvolatile memory when the power is turned on, it is necessary to wait until the voltage of the memory power supply rises and becomes stable before starting reading. For this reason, such a waiting time is required, and it is not possible to operate immediately.

SUMMARY OF THE INVENTION An object of the present invention is to provide a channel selection device that reduces the waiting time when reading data from a memory in order to eliminate the drawbacks of the conventional channel selection device as described above.

The present invention detects and maintains the reset state when the system reset circuit operates when the power of the entire channel selection device is turned on, and when the power is turned on by key input for the first time after the reset operation, the memory power supply circuit is activated. Memory read is delayed for a certain period of time until the voltage stabilizes, and then memory read is performed.
Thereafter, when the power is turned on or off by key input, the memory is not read out, and the channel can be selected without having to wait until the memory power becomes stable.

Embodiments of the present invention will be described below with reference to FIG.

1 determines key input from the keyboard and drives the power supply control circuit 4 to control power on/off;
Further, a memory control circuit controls reading and writing of data in the non-volatile memory 7 according to the output state of the reset memory circuit 2, a reset memory circuit 2 stores the reset state indicating whether the reset circuit 3 has worked, and 3 a selection memory circuit. A reset circuit supplies a reset signal for resetting the system to the reset storage circuit 2 and the memory control circuit 1 when the power of the entire station equipment is turned on. 4 controls a power switch that turns on and off the AC power input to the power supply circuit 9. 5 is a keyboard for inputting keys to turn on and off the power; 6 is a keyboard for constantly supplying power to the memory control circuit 1, the reset storage circuit 2, the reset circuit 3, and the power control circuit 4; Power supply circuit, 7
8 is a non-volatile memory that stores data so that it always matches the data of the memory control circuit 1, reads the memory data when the power is turned on, and stores the data to restore the state before the power is turned off; 8 is a non-volatile memory; 7, a deflection circuit of a television receiver that supplies negative power for reading and writing; 9, a power supply circuit for supplying power to the deflection circuit 8; 10, turning on and off the AC input to the power supply circuit 9; A second power switch 11 is a first power switch that turns on and off the AC input to the power circuit 6 and the power switch 10.

Next, the operation of the circuit will be explained. First, when the power switch 11 is turned on, the power supply circuit 6 operates, and power is supplied to the memory control circuit 1, reset storage circuit 2, reset circuit 3, and power supply control circuit 4. At this time, power-on is detected by the function of the reset circuit 3, and a reset signal for resetting the system to the initial state is supplied to the reset memory circuit 2 and the memory control circuit 1, and the reset memory circuit 2 is configured to perform a reset operation. What has been done is remembered. Further, by the reset operation, the power supply control circuit 4 is initially set to turn off the power switch 10, and enters a power-on standby state.

Next, when a key is input on the keyboard 5 to turn on the power, the power control circuit 4 operates to turn on the power switch 10, and the power supply circuit 9 is activated.
AC power is supplied, power is also supplied to the deflection circuit 8, the operation starts, and two of the FBTs in the deflection circuit 8 are
The negative voltage taken out from the next winding is the non-volatile memory 7.
is supplied to Memory control circuit 1 takes a certain period of time (approximately 300ms) until the negative voltage rises and becomes stable.
After waiting, data is read from the non-volatile memory 7 in order to obtain the data immediately before the power is turned off. Further, after reading the memory contents, each time the data in the memory control circuit 1 is rewritten, the memory contents are rewritten so that the contents always match the contents of the nonvolatile memory 7.

Next, considering the case where the power is turned off by key input, the data in the memory control circuit 1 and the data in the non-volatile memory 7 always match when the power is on, so even if the power is turned off, the power is turned off again. When the power is turned on, by reading the data in the nonvolatile memory 7, the data immediately before the power was turned off can be obtained again.

Here, each time the power is turned on, the non-volatile memory 7
If the data is read out, it would be wasted time waiting for the negative power supply voltage to stabilize. Therefore, the present invention detects the state of the reset memory circuit 2 when the power is turned on, and performs the reset operation. If the content has not been performed yet, there is no need to read the memory from the nonvolatile memory 7, and if the content has been reset, the memory read is performed.

As described above, according to the present invention, memory read time can be shortened and efficient operation can be performed.

[Brief explanation of drawings]

The figure is a circuit diagram showing an embodiment of a channel selection device according to the present invention. 1...Memory control circuit, 2...Reset storage circuit, 3...Reset circuit, 4...Power control circuit,
5...Keyboard, 6...External power supply circuit, 7...
Non-volatile memory, 8... horizontal deflection circuit, 9... power supply circuit for the horizontal deflection circuit.

Claims (1)

[Scope of Claims] 1. A channel selection device using nonvolatile memory used in a television receiver, comprising: a memory power supply circuit 8 supplied from a horizontal deflection circuit of the television receiver as a power source for the nonvolatile memory. a memory control circuit 1 that controls the nonvolatile memory and reads and writes memory contents; a reset circuit 3 that sets the memory control circuit to an initial state; and a reset state as to whether the reset circuit 3 has worked previously. an external power supply circuit 6 that supplies power to the memory control circuit 1, the reset circuit 3, and the reset memory circuit 2; and a first circuit that turns on and off the power supply to the external power supply circuit. a power supply control circuit 9 that controls the power supply for driving the horizontal deflection circuit of the television receiver; and a second switch 10 that turns on and off the power supply to the power supply control circuit 9. It consists of a key input circuit 5 for operating this power supply control circuit 9, and when the first switch 11 is turned on and the reset circuit 3 is operated, the reset state is detected and held, and after the reset operation, the first key input is performed. When the power supply control circuit 4 is operated and the second switch 10 is turned on to turn on the power, the memory power supply circuit 8
After delaying memory reading for a certain period of time until the voltage of
This channel selection device is characterized in that when the power is turned on with 0 turned on, it does not read out the memory and selects a channel without waiting until the memory power becomes stable.