Patent Application
20070143584
1. Technical Field of the Present Invention
The present invention generally relates to integrated circuits, and more specifically, to integrated circuits that automatically initialize their operational settings according to the specific requirements of the system in which the integrated circuit is used.
2. Description of Related Art
Designers of integrated circuits are designing common system boards that support multiple versions of an integrated circuit where each version has a differing frequency, voltage, and/or heat dissipation requirement. This design allows a single common system board to be used in multiple product lines that are distinguished from one another based upon performance type criteria (e.g. cell phones).
Manufacturers of the integrated circuits for these systems often maintain multiple part numbers for the various integrated circuits that performed similar functionality but were manufactured using differing technologies. The manufacturing in differing technologies often allows increased functionality and operation of the integrated circuit at lower voltages and higher frequencies.
It would be a distinct advantage for the both the manufacturer and designer if there were an integrated circuit that would automatically initialize its operational settings according to the requirements of the system in which the integrated circuit is being used. The designer would avoid the complex and burdensome issues previously described in supporting these multiple versions and the manufacturer could eliminate the need for multiple part numbers and the like.
In one aspect, the present invention is an integrated circuit having memory that stores sets of operating conditions of the integrated circuit under specific environmental conditions. The integrated circuit includes an access circuit that accesses and reads one of the stored sets of operating conditions that corresponds to one or more environmental conditions of a system in which the integrated circuit is being used. The integrated circuit also includes a control circuit that alters the operation of specific elements of the system to support the set of read operating conditions.
The present invention will be better understood and its numerous objects and advantages will become more apparent to those skilled in the art by reference to the following drawings, in conjunction with the accompanying specification, in which:
The present invention is a method and apparatus for an integrated circuit to automatically initialize its operational settings according to the requirements of the system in which the integrated circuit is being used. This is accomplished by using a unique identification value stored in the integrated circuit in combination with a look-up table containing various final test values for the integrated circuit for characteristics such as voltage, frequency and thermal requirements. These final test values are then read and used by the system to set characteristics of the integrated circuit such as the frequency, voltage and thermal cooling requirements according to the design of the particular system (e.g. 1.5 v, 1.2 MHz, 3 Watts).
Reference now being made to
Reference now being made to
Integrated circuit 104 includes a CPU or Microprocessor 202, Environmental Control Unit 224, Variable Voltage Generator 222, Oscillator 220, Variable Clock Generator 218, and Interface to Thermal Controls 216.
Microprocessor 202 can be, for example, a custom processor having specialized components or a common processor such as the PowerPC™ by IBM. In this embodiment, the Microprocessor 202 is illustrated as containing common elements such as Controller Logic 204, Instruction Decoding 206, Arithmetic Processing 208, Thermal Environment Controls 210, and Clock Multiplier/Distribution Tree 212. The purpose and operation of these common elements are well understood, and therefore, further explanation is unnecessary.
Microprocessor 202 also includes a bank of fuses 214a-n that can be implemented using various schemes such as anti-fuses, metal and the like. Although the Microprocessor 202 uses fuses in this embodiment, it should be understood that any type of structure that is capable of retaining its logical value in some manner could be used (e.g. non-volatile memory, or low power schemes to a dedicated memory unit after power has been discontinued to the Microprocessor 202).
The Interface to Thermal Controls Unit 216 provides a convenient interface from the Thermal Environment Controls 210 and Environmental Control Unit 224 to thermal controls that are external to the integrated circuit 104 such as a fan or other heat dissipation device(s). The Thermal Controls Unit 216 can control the heat dissipation devices itself or provide information such as thermal requirements to external controls.
The Variable Clock Generator 218 is used in combination with the Oscillator 220 to generate a clock frequency based upon information provided from the Environmental Control Unit 224. The clock frequency is provided to the Clock Multiplier/Distribution Tree 212.
The Environmental Control unit 224 includes an Electronic Chip Identification (ECID) Read Sequencer 228, a Look-up Table 226, optional Captured Electronic Chip Identification (ECID) Unit 230, and Index 232. The Environmental Control Unit 224 can reside in the Microprocessor 202 itself, the integrated circuit 104 (as shown), or on the board that the integrated circuit 104 is mounted (not shown).
The Electronic Chip Identification (ECID) Read Sequencer 228 is used to read the value represented by the bank of fuses 214a-n (Electronic Chip Identification (ECID)). The Captured ECID unit 230 retrieves the ECID and implemented in non-volatile memory or the like to store the (ECID) so that the Microprocessor 202 is not required to be powered on to retrieve the ECID during subsequent power cycle sequences. The Index 232 is used to access the Look-up Table 226 using the ECID as an index as explained below.
As each integrated circuit is manufactured, it is typically characterized at module final test for operating frequency and current drain. Some of these integrated circuits will require a higher voltage to reach the desired frequency; others will operate at the desired frequency but will dissipate too much power at certain voltage levels. As each integrated circuit is tested, these characteristics are recorded in the Look-up Table 226. Look-up Table 226 can be implemented in any type of non-volatile memory.
The organization of these characteristics can take many forms. The preferred embodiment of the present invention uses a Look-up Table 226 that organizes the characteristics (e.g. Thermal, Frequency, and Voltage) such that the ECID represents one or more of the Frequency, Voltage, or Thermal requirements of the System 100. The ECID value is then used to access the appropriate column in the Look-up Table 226 to retrieve the missing information corresponding to the ECID representation (e.g. ECID represents Frequency and Voltage, then this value is used to determine the thermal requirements of the Microprocessor 202).
An example of how the Look-up Table 226 could be represented is illustrated in the Table below.
In an alternative embodiment of the present invention, the Microprocessor does not require the use of fuses 214a-n, and the Environmental Control Unit 224 does not require the use of the ECID Reader Sequencer Unit 228 or Captured ECID Unit 230. In this alternative embodiment, the Index Unit 232 is used by the System 104 to specify access the table using a particular value for a characteristic such as frequency and retrieves the remaining associated characteristic values (e.g. voltage level and thermal requirement).
The functions and interactions between the various components of the integrated circuit 104 are explained below in connection with
Reference now being made to
If the ECID has been captured the method proceeds to read the Look-up Table 226 as described below. If, however, the ECID value has not been captured, then the System 100 applies enough power to the integrated circuit 104 in order to be able to read the value of the ECID from the fuses 214a-n using the ECID Read Sequencer 228 (Steps 306 and 308). In addition, as an optional implementation, the Captured ECID Unit 230 captures the ECID for later use (Step 310).
The value of the ECID is then used by Environmental Control unit 224 to access the Look-up Table 226 in combination with the desired frequency, voltage, or other characteristic and retrieves the values for the remaining environmental characteristics such as frequency or voltage and thermal/cooling requirements (Step 312). These values are used by the Environmental Control Unit 224 to set the Variable Clock Generator 218 to generate a desired frequency using the Oscillator circuitry 220 and provide a clock signal to the Clock Multiplier Distribution Tree 212.
The Environmental Control Unit 224 uses the thermal value to control the Interface to Thermal Controls unit 216 to set the appropriate heat dissipation requirements of the Microprocessor 202 such as fan speed or the like.
The Environmental Control Unit 224 uses the voltage value to set the core voltage of the Microprocessor 202 to a value that supports the selected frequency (Step 312).
As previously explained, in an alternative embodiment of the present invention, the Environmental Control Unit 224 does not require the use of the ECID and can be accessed by the System 104 to specify a characteristic stored in the Look-up Table 226. In this alternative embodiment, steps 306 to 310 would not be required and the method would implement steps 312 to 316 after access by the System 100 in this alternative embodiment.
It is thus believed that the operation and construction of the present invention will be apparent from the foregoing description. While the method and system shown and described has been characterized as being preferred, it will be readily apparent that various changes and/or modifications could be made without departing from the spirit and scope of the present invention as defined in the following claims.
