Method for software driven generation of multiple simultaneous high speed pulse width modulated signals
First Claim
1. A method of generating a plurality of pulse width modulated (PWM) signals provided on a corresponding plurality of I/O pins, comprising acts of:
- A) determining said plurality of PWM signals from at least one set of pre-computed values corresponding to a plurality of sub periods of a PWM cycle,B) updating at least one of the plurality of PWM signals by executing a first write to at least one of the corresponding plurality of I/O pins,C) executing a series of instructions consuming a predetermined amount of time,D) executing a second write to the at least one of the corresponding plurality of I/O pins, andE) advancing a sub period bookkeeping value to point to a next sub period in the PWM cycle,wherein the act B) includes acts of;
B1) conducting a single array read based on the at least one set of pre-computed values; and
B2) executing the first write as a single write to the corresponding plurality of I/O pins following the act B1).
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Accused Products
Abstract
Systems and methods can provide, in one aspect, a method for modulating the pulse width of control signals generated on a plurality of separate channels. In one practice, the methods described herein are suitable for execution on a microprocessor or micro controller platform that includes a timer interrupt mechanism which will generate an interrupt in response to a timer counting down a selected time interval or time period. In one practice, the timer is set to count down a period of time that is representative of a portion, or sub period, of the PWM cycle. Upon expiration of that time period, the timer executes an interrupt that causes the micro controller to enter an interrupt service routine (ISR) that can further modulate the PWM cycle of one or more signals.
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Citations
40 Claims
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1. A method of generating a plurality of pulse width modulated (PWM) signals provided on a corresponding plurality of I/O pins, comprising acts of:
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A) determining said plurality of PWM signals from at least one set of pre-computed values corresponding to a plurality of sub periods of a PWM cycle, B) updating at least one of the plurality of PWM signals by executing a first write to at least one of the corresponding plurality of I/O pins, C) executing a series of instructions consuming a predetermined amount of time, D) executing a second write to the at least one of the corresponding plurality of I/O pins, and E) advancing a sub period bookkeeping value to point to a next sub period in the PWM cycle, wherein the act B) includes acts of; B1) conducting a single array read based on the at least one set of pre-computed values; and B2) executing the first write as a single write to the corresponding plurality of I/O pins following the act B1). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A system for modulating a pulse of at least one digital signal, comprising:
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a memory having stored therein at least one set of pre-computed values, each pre-computed value being representative of a signal level for said at least one digital signal; a programmable device having a program memory and a timer, said program memory storing a set of instructions capable of directing said programmable device to monitor said timer, and in response to a signal generated by said timer, to access said set of pre-computed values for selecting at least one signal level for said at least one digital signal; an interrupt service routine capable of directing said programmable device to further modulate said at least one digital signal; an amplifier for adjusting a characteristic of said at least one digital signal; and a light source coupled to said at least one digital signal, wherein said at least one digital signal is configured to control at least one operating characteristic of said light source, wherein; the light source comprises at least one LED-based light source configured to output at least first radiation having a first spectrum and second radiation having a second spectrum different than the first spectrum; and the at least one digital signal includes a plurality of digital signals configured to independently control at least a first intensity of the first radiation and a second intensity of the second radiation so as to controllably vary at least an overall color of a total visible radiation generated by the light source. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40)
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Specification