Non-intrusive in-system programming using in-system programming circuitry coupled to oscillation circuitry for entering, exiting, and performing in-system programming responsive to oscillation circuitry signals
First Claim
1. A method for programming a memory on an integrated circuit including entering a programming mode of the integrated circuit, wherein entering the programming mode comprises:
- turning-off a first oscillation signal of a first frequency within the integrated circuit; and
turning-on a second oscillation signal of a second frequency within the integrated circuit.
6 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus for In-System Programming which overcomes the above-described disadvantages. The method and apparatus of the ISP system interfaces with the two oscillator (instead of I/O) pins on the microcontroller. By interfacing with the two oscillator pins, the need for extra isolation circuitry to isolate other circuits from the ISP circuits is avoided in most circumstances, without incurring the expense of an expensive JTAG tester or extra dedicated pins. The amount of isolation circuitry necessary is reduced because the two oscillator pins are usually connected to passive components (registers, capacitors, or crystals) which cannot be damaged by the relatively high programming voltages and which do not produce signals that would interfere with the ISP programming signals.
34 Citations
13 Claims
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1. A method for programming a memory on an integrated circuit including entering a programming mode of the integrated circuit, wherein entering the programming mode comprises:
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turning-off a first oscillation signal of a first frequency within the integrated circuit; and turning-on a second oscillation signal of a second frequency within the integrated circuit. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for programming a memory on an integrated circuit comprising:
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sending a periodic carrier signal with a frequency equal to a frequency of a clock internal to the integrated circuit; modulating a plurality of cycles of the periodic carrier signal to send a command to the integrated circuit; and modulating a plurality of cycles of the periodic carrier signal to send/receive data to/from the memory on the integrated circuit. - View Dependent Claims (8, 9)
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10. An integrated circuit device comprising:
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a processing unit; an EEPROM for providing instructions to the processing unit; an oscillator for providing a clock to the processing unit; programming circuitry for programming the EEPROM; a first pin for providing timing to the oscillation circuitry during an operating mode and for providing a relatively high voltage to the EEPROM during a programming mode; and a second pin for communicating with the EEPROM. - View Dependent Claims (11)
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12. An integrated circuit comprising:
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a processing unit; an EEPROM for providing instructions to the processing unit; an oscillator for providing a clock to the processing unit; oscillation circuitry for coupling the oscillator to the processing unit; and in-system programming circuitry coupled to the oscillation circuitry for entering, exiting, and performing in-system programming responsive to signals received from the oscillation circuitry. - View Dependent Claims (13)
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Specification