Circuit arrangement for a control device of a vehicle

Abstract

The invention relates to a circuit arrangement for a control device of a vehicle, comprising at least one ASIC module having at least one analog input and at least one analog output, and at least one multiplexer having at least one output electrically connected to the at least one analog input and at least two inputs, the circuit arrangement electrically connecting one of the at least two inputs to the at least one output in dependence on at least one control signal, wherein the at least one ASIC module has a multiplexing function which generates the at least one control signal and outputs the at least one control signal via the at least one analog output to at least one control input of the at least one multiplexer. The invention also relates to a control device having at least one such circuit arrangement.

Description

Technical Field

[0001] This invention relates to a circuit layout structure for a control instrument for a vehicle. The subject matter of this invention also relates to a control instrument for a vehicle having at least one such circuit layout structure. Background Technology

[0002] In known vehicle control instruments, particularly airbag control instruments, a circuit layout with at least one highly integrated ASIC module (ASIC: Application-Specific Integrated Circuit) is used. Such an ASIC module typically has a number of analog inputs to read signals from resistance-based or current-based sensors and / or switches, for example, from the vehicle. Furthermore, this ASIC module typically also has analog outputs to control, for example, drivers for ignition circuits or discrete lamps. If the number of integrated analog inputs is insufficient, additional ASIC modules can be used. Alternatively, a multiplexer can be connected upstream of the analog inputs of the ASIC module, allowing each analog input to be used for multiple analog input signals, which can be alternately connected to the corresponding analog input. This multiplexer is typically controlled by software in an evaluation and control unit of the control instrument, preferably configured as a microcontroller. This requires synchronizing the operation of the multiplexer with the typically highly automated testing and / or reading processes of the ASIC module. Furthermore, the analog inputs of the microcontroller can also be directly used as additional analog inputs. However, these do not provide sufficient diagnostic capabilities, so, for example, Hall sensors that require a limited operating current cannot be used with analog inputs of microcontrollers to the same extent as they are used with analog inputs of ASIC modules. Summary of the Invention

[0003] The advantage of the circuit layout of the vehicle control instrument having the features of independent claim 1 is that at least one analog output of the ASIC module is reconfigured such that, instead of being controlled by the microcontroller as a standard output, the analog output automatically controls the multiplexer within the multiplexing function of the ASIC module, thereby increasing the number of analog inputs available for analog signals. For example, if the analog output of the ASIC module is used to control the multiplexer, the number of available analog inputs can effectively be doubled. When using two analog outputs, the number of available analog inputs can be quadrupled. In principle, analog signals whose number is 2 to the power of N times the number of analog inputs present on the ASIC module can be read, where N corresponds to the number of analog outputs used.

[0004] Since not all existing analog outputs of at least one ASIC module are typically used, these outputs can be used to control the multiplexer. This advantageously reduces the number of analog inputs in the ASIC module. The multiplexing function implemented in the ASIC module can be designed such that the internal processes of the ASIC module for reading analog signals can be run at least once more, and diagnostic functions can be repeated in the same manner. Furthermore, the costly synchronization in the software of the control instrument and the evaluation of the control unit can be eliminated, and potential error states and runtime effects can be avoided.

[0005] Embodiments of the present invention provide a circuit layout for a control instrument for a vehicle, comprising at least one ASIC module and at least one multiplexer. The ASIC module has at least one analog input and at least one analog output. The multiplexer has at least one output electrically connected to the at least one analog input and at least two inputs, and is configured to electrically connect one of the at least two inputs to the at least one output according to at least one control signal. Here, the at least one ASIC module has a multiplexing function implemented to generate the at least one control signal and output it through the at least one analog output to at least one control input of the at least one multiplexer.

[0006] Furthermore, a control instrument for a vehicle is proposed, comprising an evaluation and control unit and at least one such circuit layout. Here, the evaluation and control unit is connected to at least one control input terminal of an ASIC module of the ASIC circuit layout.

[0007] In the current context, the evaluation and control unit can be understood as an electronic unit, such as a microcontroller, that processes, and more precisely, evaluates, the detected sensor signals. The evaluation and control unit may have at least one interface, which can be in hardware and / or software form. In a hardware configuration, the interface may, for example, be part of a so-called system ASIC that incorporates various functions of the evaluation and control unit. However, the interface may also be a separate integrated circuit or at least partially composed of discrete structural elements. In a software-suitable configuration, the interface may be a software module, which, for example, exists on the microcontroller along with other software modules. A computer program product with program code stored on a machine-readable medium, such as semiconductor memory, hard disk storage, or optical storage, is also advantageous, and this program code is used for evaluation when the evaluation and control unit executes the program.

[0008] The circuit layout of the control instrument for a vehicle given in independent claim 1 can be advantageously improved by the measures and improvements listed in the dependent claims.

[0009] Of particular advantage, the multiplexing function can be further implemented to repeatedly activate the read function at at least one analog input until the analog signal at at least two inputs of the multiplexer has been read. If the multiplexer is implemented, for example, as a 2:1 multiplexer, two analog signals from two channels of the read function can be read sequentially at the analog inputs of the ASIC module. For a 3:1 multiplexer, three analog signals from three channels of the read function can be read sequentially at the analog inputs of the ASIC module, for example.

[0010] In advantageous circuit layout designs, the readout functionality may include diagnostic functions for identifying errors. These diagnostic functions may include, for example, functions for identifying errors such as cross-coupling.

[0011] In another advantageous design of the circuit layout, the number of outputs of the multiplexer can correspond to the number of analog inputs of the ASIC module. Thus, all analog inputs can be used to sequentially read multiple analog signals. Alternatively, the multiplexer can only be used to sequentially read multiple analog signals from a specific number of analog inputs of the ASIC module.

[0012] In another advantageous design of the circuit layout, the number of input terminals can be based on the number of available analog output terminals of the ASIC module, which can be sequentially electrically connected to at least one output terminal of the multiplexer and at least one analog input terminal of the ASIC module. If the ASIC module has only one available analog output terminal, the two input terminals of the multiplexer can, for example, be sequentially connected to the analog output terminal. If the ASIC module has two available analog output terminals, up to four input terminals of the multiplexer can be sequentially connected to the analog output terminal.

[0013] In another advantageous design of the circuit layout, the multiplexer can be a discrete transistor network. Alternatively, the multiplexer can be an integrated circuit. Attached Figure Description

[0014] Embodiments of the invention and conventional control instruments with ASIC modules are illustrated in the accompanying drawings, which are described in detail below. In the drawings, the same reference numerals denote parts or elements that perform the same or similar functions.

[0015] Figure 1 A schematic block diagram of a conventional control instrument is shown; and

[0016] Figure 2 A block diagram of an embodiment of a control instrument according to the invention for a vehicle is shown, having an embodiment of a circuit arrangement structure according to the invention for a control instrument for a vehicle. Detailed Implementation

[0017] from Figure 1 As can be seen, the conventional control instrument 1 shown includes an ASIC module 3, an evaluation and control unit 5, and a multiplexer 7. From Figure 1 It can also be seen that ASIC module 3 has four analog input terminals AIN1, AIN2, AIN3, and AIN4, which are electrically connected to the output terminals A1, A2, A3, and A4 of multiplexer 7, respectively. The ASIC module also has two analog output terminals AO1 and AO2. Multiplexer 7 has eight input terminals E1A, E2A, E3A, E4A, E1B, E2B, E3B, and E4B, where every two input terminals E1A, E2A, E3A, E4A, E1B, E2B, E3B, and E4B can be connected to one of the four output terminals A1, A2, A3, and A4 of multiplexer 7, respectively. Here, the control input terminal SAB of multiplexer 7 and the control input terminal SPI of ASIC module 3 are connected to evaluation and control unit 5, enabling evaluation and control unit 5 to control multiplexer 7 and ASIC module 3. Therefore, the evaluation and control unit 5 must synchronize the operation of the multiplexer 7 with the highly automated testing and reading process of the ASIC module 3, so that in the first reading process, the four first input terminals E1A, E2A, E3A, and E4A of the multiplexer 7 are connected to one of the four output terminals A1, A2, A3, and A4 of the multiplexer 7, respectively, and in the second reading process, the four second input terminals E1B, E2B, E3B, and E4B of the multiplexer 7 are connected to one of the four output terminals A1, A2, A3, and A4 of the multiplexer 7, respectively.

[0018] from Figure 2 As can be seen, the illustrated embodiment of the control instrument 20 according to the invention for a vehicle includes an evaluation and control unit 18 and a circuit layout structure 10 according to the invention. Here, the evaluation and control unit 18 in the illustrated embodiment is a microcontroller 18A and is connected to at least one control input terminal (SPI) of the ASIC module 12 of the circuit layout structure 10.

[0019] from Figure 2 It can also be seen that the illustrated embodiment of the circuit layout structure 10 for the control instrument 20 for the vehicle includes at least one ASIC module 12 and at least one multiplexer 16. The ASIC module has at least one analog input terminal AIN1, AIN2, AIN3, AIN4 and at least one analog output terminal AO1, AO2. The multiplexer includes at least one output terminal A1, A2, A3, A4 electrically connected to at least one analog input terminal AIN1, AIN2, AIN3, AIN4 and at least two input terminals E1A, E2A, E3A, E4A, E1B, E2B, E3B, E4B, and one of the at least two input terminals E1A, E2A, E3A, E4A, E1B, E2B, E3B, E4B is electrically connected to the at least one output terminal A1, A2, A3, A4 according to at least one control signal. Here, at least one ASIC module 12 has a multiplexing function 14, which generates the at least one control signal and outputs it to at least one control input SAB of the at least one analog output terminal AO1, AO2.

[0020] from Figure 2 It can also be seen that the ASIC module 12 has four analog input terminals AIN1, AIN2, AIN3, and AIN4, which are electrically connected to the output terminals A1, A2, A3, and A4 of the multiplexer 7, respectively. The ASIC module also has two analog output terminals AO1 and AO2, wherein the first analog input terminal AO1 is electrically connected to the control input terminal SAB of the multiplexer 16. In the embodiment shown in the circuit layout structure 10, the multiplexer 16 is a discrete transistor network 16A, which has four transistors T1, T2, T3, and T4 schematically shown as switches. The four transistors T1, T2, T3, and T4 are switched simultaneously by a control signal at the control input terminal SAB. In an alternative embodiment not shown, the multiplexer 16 is an integrated circuit.

[0021] from Figure 2It can also be seen that the multiplexer 16 in the illustrated embodiment has eight input terminals E1A, E2A, E3A, E4A, E1B, E2B, E3B, E4B and four output terminals A1, A2, A3, A4. Here, the first input terminal E1A and the second input terminal E1B can be connected to the first output terminal A1 through the first transistor T1. Another first input terminal E2A and another second input terminal E2B can be connected to the second output terminal A2 through the second transistor T2. Another first input terminal E3A and another second input terminal E3B can be connected to the third output terminal A3 through the third transistor T3. Another first input terminal E4A and another second input terminal E4B can be connected to the fourth output terminal A4 through the fourth transistor T4. Therefore, during the first reading process, the four first input terminals E1A, E2A, E3A, and E4A of the multiplexer 16 are connected to one of the output terminals A1, A2, A3, and A4 of the multiplexer 16, respectively. This allows the four analog signals located at the four first input terminals E1A, E2A, E3A, and E4A of the multiplexer 16 to be transferred to the four analog input terminals AIN1, AIN2, AIN3, and AIN4 of the ASIC module 12 and read. During the second reading process, the four second input terminals E1B, E2B, E3B, and E4B of the multiplexer 16 are connected to one of the output terminals A1, A2, A3, and A4 of the multiplexer 16, respectively. This allows the four additional analog signals located at the four second input terminals E1B, E2B, E3B, and E4B of the multiplexer 16 to be transferred to the four analog input terminals AIN1, AIN2, AIN3, and AIN4 of the ASIC module 12 and read. This means that the multiplexing function 14 of the ASIC module 12 repeatedly activates the read function of the analog input terminals AIN1, AIN2, AIN3, and AIN4 until the analog signals at the input terminals E1A, E2A, E3A, E4A, E1B, E2B, E3B, and E4B of the multiplexer 16 have been read. Thus, the number of analog signals to be read can be increased from four to eight.

[0022] In the embodiment shown in the circuit layout 10, the reading function includes a diagnostic function for identifying errors.

[0023] from Figure 2It can also be seen that in the embodiment shown in the circuit layout structure 10, the number of output terminals A1, A2, A3, A4 of the multiplexer 16 corresponds to the number of analog input terminals AIN1, AIN2, AIN3, AIN4 of the ASIC module 12. Thus, eight analog signals can be read through the four analog input terminals AIN1, AIN2, AIN3, AIN4 of the ASIC module 12. If only seven analog signals are to be read through the four analog input terminals AIN1, AIN2, AIN3, AIN4 of the ASIC module 12, a multiplexer with six input terminals E1A, E2A, E3A, E1B, E2B, E3B and three output terminals A1, A2, A3 can be used, wherein only three analog input terminals AIN1, AIN2, AIN3 of the ASIC module 12 are connected to one of the output terminals A1, A2, A3 of the multiplexer, respectively, so that the ASIC module 12 can read a total of seven analog signals.

[0024] The number of input terminals E1A, E2A, E3A, E4A, E1B, E2B, E3B, E4B that can be electrically connected sequentially to at least one output terminal A1, A2, A3, A4 of multiplexer 16 and at least one analog input terminal AIN1, AIN2, AIN3, AIN4 of ASIC module 12 is based on the number of available analog output terminals AO1, AO2 of ASIC module 12. In the illustrated embodiment, only the first analog output terminal of ASIC module 12 can be used to control multiplexer 16, so that only every two input terminals E1A, E2A, E3A, E4A, E1B, E2B, E3B, E4B can be connected to the corresponding output terminals A1, A2, A2, A4. The second analog output terminal AO2 of ASIC module 12 is used to output analog signals.

Claims

1. A circuit layout structure (10) for a control instrument (20) for a vehicle, the circuit layout structure comprising at least one ASIC module (12) and at least one multiplexer (16), the ASIC module having at least one analog input terminal (AIN1, AIN2, AIN3, AIN4) and at least one analog output terminal (AO1, AO2), the multiplexer comprising at least one output terminal (A1, A2, A3, A4) electrically connected to the at least one analog input terminal (AIN1, AIN2, AIN3, AIN4) and at least two input terminals (E1A, E2A, E3A, E4A, E1B, E2B, E3B, E4B), the circuit layout structure electrically connecting one of the at least two input terminals (E1A, E2A, E3A, E4A, E1B, E2B, E3B, E4B) to the at least one output terminal (A1, A2, A3, A4) according to at least one control signal, wherein, At least one of the ASIC modules (12) has a multiplexing function (14) that generates the at least one control signal and outputs the at least one control signal to at least one control input (SAB) of at least one of the multiplexers (16) through the at least one analog output (AO1, AO2).

2. The circuit layout structure (10) according to claim 1, characterized in that, The multiplexing function (14) further repeatedly activates the read function of at least one analog input terminal (AIN1, AIN2, AIN3, AIN4) until the analog signal at at least two input terminals (E1A, E2A, E3A, E4A, E1B, E2B, E3B, E4B) of the multiplexer (16) has been read.

3. The circuit layout structure (10) according to claim 2, characterized in that, The reading function includes diagnostic functions for identifying errors.

4. The circuit arrangement structure (10) according to any one of claims 1 to 3, characterized in that, The number of output terminals (A1, A2, A3, A4) of the multiplexer (16) corresponds to the number of analog input terminals (AIN1, AIN2, AIN3, AIN4) of the ASIC module (12).

5. The circuit arrangement structure (10) according to any one of claims 1 to 3, characterized in that, The number of input terminals (E1A, E2A, E3A, E4A, E1B, E2B, E3B, E4B) is based on the number of available analog output terminals (AO1, AO2) of the ASIC module (12), which can be electrically connected in sequence to at least one output terminal (A1, A2, A3, A4) of the multiplexer (16) and at least one analog input terminal (AIN1, AIN2, AIN3, AIN4) of the ASIC module (12).

6. The circuit arrangement structure (10) according to any one of claims 1 to 3, characterized in that, The multiplexer (16) is either a discrete transistor network (16A) or an integrated circuit.

7. A control instrument (20) for a vehicle, the control instrument having an evaluation and control unit (18) and at least one ASIC circuit layout (10) according to any one of claims 1 to 6, wherein, The evaluation and control unit (18) is electrically connected to at least one control input (SPI) terminal of the ASIC module (12) of the ASIC circuit layout structure (10).

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