Control interface for LCD dot matrix displays and method of operating the same
First Claim
1. A control interface for a liquid crystal display, said interface comprising:
- a pair of control devices connected to the liquid crystal display for controlling the same, each said control device having a 4-bit microprocessor mode; and
an 8-bit microprocessor for simultaneously controlling the pair of control devices, said microprocessor having eight data bit outputs, with its four lowest data bits of the microprocessor only being connected to one control device, and with its four highest data bits only being connected to the other control device.
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Accused Products
Abstract
A control interface for a liquid crystal display having more than 80 characters uses a pair of controller/driver devices each having inputs for eight data bits but being adaptable to operate with four data bits from a 4-bit microprocessor. A standard 8-bit microprocessor is used to control the controller/driver devices by connecting the four bits of a low data nibble of the microprocessor to the four high data bits of one controller/driver and four bits of a high data nibble of the microprocessor to the four high data bits of the other controller/driver. The control interface can interface to liquid crystal displays with less than 80 characters without microprocessor modification.
23 Citations
23 Claims
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1. A control interface for a liquid crystal display, said interface comprising:
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a pair of control devices connected to the liquid crystal display for controlling the same, each said control device having a 4-bit microprocessor mode; and an 8-bit microprocessor for simultaneously controlling the pair of control devices, said microprocessor having eight data bit outputs, with its four lowest data bits of the microprocessor only being connected to one control device, and with its four highest data bits only being connected to the other control device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A liquid crystal display device, comprising:
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a liquid crystal display; LCD driver means for driving said liquid crystal display; a pair of LCD control devices connected to said driver means and said liquid crystal display for controlling the same, each said LCD control device by a 4-bit microprocessor mode; and an 8-bit microprocessor for simultaneously controlling the pair of LCD control devices, said microprocessor having eight data bit outputs, with its four lowest data bits only being connected to one LCD control device, and with its four highest data bits only being connected to the other LCD control device. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method of controlling a liquid crystal display device including a liquid crystal display for displaying more than 80 characters, a pair of controller/drivers for controlling and driving the display, said controller/drivers having an eight-bit or a four-bit microprocessor mode and an eight-bit microprocessor for simultaneously controlling said controller/drivers, said method comprising the steps of:
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setting said controller/drivers in a four-bit microprocessor mode for processing four bits of data at a time; providing only a lowest four bits from the eight-bit microprocessor to one controller/driver; providing only a highest four bits from the eight-bit microprocessor to the other controller/driver; and operating the eight-bit microprocessor in a two-step sequential transfer mode to transfer eight control bits per controller/driver in four bits each step, whereby the controller/drivers each receive eight control bits. - View Dependent Claims (22)
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23. A control interface for a liquid crystal display, said interface comprising:
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a pair of LCD control devices connected to the liquid crystal display for controlling the same, each said LCD control device having an n-bit microprocessor mode; and a 2 n-bit microprocessor for simultaneously controlling the pair of LCD control devices, the 2 n-bit microprocessor having 2 n data bit outputs, with its n lowest data bits of the microprocessor only being connected to one LCD control device, and with its n highest data bits only being connected to the other LCD control device.
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Specification