JPH0282377A - Semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To reduce the number of the development of an emulator integrated circuit by exchanging the data, which are exchanged between a built-in microcomputer and a circuit block other than the computer, between the circuit block and the outside of the integrated circuit as well. CONSTITUTION:A mode switching signal 9 is inputted form the outside of a semiconductor integrated circuit 1, and by an external terminal input/output switching circuit 7, based on the mode switching signal 9, a signal group inputted/outputted from at least two parts 2 and 8 inside the semiconductor integrated circuit 1 to/from the outside of the semiconductor is switched and inputted/outputted. A bus switching part 4 inputs/outputs the signal group from a microcomputer 10 to/from the external terminal input/output switching circuit 7, and separates the connection between the microcomputer 10 and circuit blocks 3 and 6 based on the mode switching signal 9. Further, the signal inputted/ outputted from the circuit blocks 3 and 6 to/from the microcomputer 10 based on the mode switching signal 9 is newly inputted/outputted through the external terminal input/output switching circuit 7 to/from the outside of the semiconduc tor integrated circuit. Thus, the number of the development of the emulator integrated circuit can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor integrated circuit, and particularly to a semiconductor integrated circuit in which a microcomputer and various circuits are combined on the same device.

[Conventional technology]

BACKGROUND ART Currently, a method of designing a new integrated circuit using a microcomputer (hereinafter referred to as a CPU) as the main device and combining devices with various other functions on the same device is becoming popular.

This has the advantage of reducing the mounting area by requiring only one device instead of two or more devices in the past.

Although this method has great advantages in terms of implementation and has no particular problems when considered only from the perspective of integrated circuits, it has some difficult problems when considered from the point of view of program development. This point will be discussed below.

First, FIG. 2 is a configuration diagram of a semiconductor integrated circuit 20 in which a conventional type CPU and circuit blocks having other functions are combined. This is the main CPUl0 and CPU
A dedicated unit 3 having functions other than l0, a control unit 6 that determines which dedicated unit receives input/output from the CPU l0 first and which input/output is external to the integrated circuit, and buses lla and 1 that connect them.
It further comprises a signal group bus 2 that inputs and outputs from the dedicated section to the outside of the integrated circuit, and a signal group bus 8 that inputs and outputs from the CPU10 to the outside of the integrated circuit. The signal group bus 2.8 is installed as a terminal on the integrated circuit.

Normally, microcomputer program development involves program execution and interruption from any program address,
The process proceeds while checking the internal state of the microcomputer after the interruption, changing the state, and tracing the execution state of the microcomputer (hereinafter referred to as the evaluation function).

Therefore, we decided to develop using a system called an in-circuit emulator that has such functions. This method is performed by connecting this emulator via a connector called a probe to the place where the microcomputer would normally be mounted, and making the emulator simulate the same operation as the integrated circuit.

Without such a system, programs cannot be developed effectively on any microcomputer.

The configuration of an emulator for the integrated circuit shown in FIG. 2 (this is mainly a microcomputer, so it can be considered a type of microcomputer, and an emulator is also required) is as shown in FIG. 3. What should be noted here is that the emulator must perform the same operation as the integrated circuit 20 in a pseudo manner, and must also be equipped with the evaluation functions described above. However, for this purpose, it is not practical to assemble an emulator using only TTT, devices, etc. due to execution speed issues and circuit scale. Furthermore, it is not practical in terms of process technology and development man-hours to provide all of these evaluation functions on one integrated circuit.

Therefore, the integrated circuit 20 is usually divided into several integrated circuits, and various circuits (for example, break condition detection circuit, trace memory, trace memory control circuit, etc.) are divided into several integrated circuits.
is added to these divided integrated circuits to construct an emulator. In addition, usually the CPU10 is made into a single integrated circuit, and it is equipped with some evaluation functions (for example, means for checking the internal state at the time of a break) (hereinafter, such an integrated circuit will be referred to as an evaluation chip). . This is because even if a new function is added to the dedicated section, with this configuration, only the dedicated section can be changed without changing the emulator of the CPU section.

The other components are an integrated circuit (hereinafter referred to as dedicated part LSI) 31. There is a bus 32 (which is the same as the bus 2 in FIG. 2=5-) input and output from the dedicated part LSI 31, and a bus 42 which is the same as the bus llb in FIG. In addition, the bus 41 input and output from the evaluation chip is the bus lla in FIG. 2, and the bus 36 is the bus 8.
are the same as each other.

The emulator includes these evaluation chips 40 and a dedicated LSI.
31 is used, but in addition to this, the complex execution/interruption that is actually required for program development is performed by controlling the simple functions mentioned above on the evaluation chip, and it also has a Sarani trace function and a man-machine interface function with the emulator. There is also a controller section 39 , and a circuit control circuit 37 equivalent to the control section 6 in the integrated circuit 20 . Furthermore, there is an interface circuit 33 between the emulator and the outside.

As shown here, in the conventional configuration of this type of semiconductor integrated circuit, when creating an emulator necessary for program development, it is necessary to design an evaluation chip, a dedicated LSI, a control circuit, and a controller. There is. In addition to this, of course, the purpose of the integrated circuit itself had to be designed.

In order to avoid this kind of thing, the following attempts have been made.

■ We have created a family of semiconductor integrated circuits that have the same architecture but differ only in dedicated parts.
The emulator for each integrated circuit in the same family uses a single evaluation chip with the same architecture as that family and with the maximum possible resources (including all dedicated parts in the NOA family). be.

■ A method that attempts to cover everything with the target integrated circuit (Siddal Chiff microcomputer) and niter without developing an evaluation chip.

This microcomputer includes a mode switching means for switching between two modes, a normal mode and a debug mode, an instruction decoder for decoding instructions, a plurality of external terminals, an external terminal control circuit, and a mode switching means when switched to the debug mode. The device further includes function assignment designating means for designating a predetermined external terminal out of a plurality of external terminals as an instruction input terminal or a data input/output terminal, and designating the single-chip microcomputer as a mask or slave. When the mode switching means is switched to the normal mode, the instruction decoder decodes the instructions output from the program storage memory in the computer, and when the mode switching means is switched to the debug mode, the instruction decoder is decoded by the function assignment specifying means. Decodes the command input from the external terminal specified as the input terminal. If this microcomputer is designated as a slave and an instruction to control an external terminal that is not designated as either an instruction input terminal or a data input/output terminal (that is, an instruction for a dedicated section) is decoded, the external terminal Input or output the data for operating the from the external terminal specified as the data input/output terminal. Also, when this microcomputer is designated as a mask and an instruction to operate an external terminal designated as an instruction input terminal or the data input/output terminal is decoded, data to be operated on the external terminal is designated as the data input/output terminal. Output or input to the specified external terminal.

In this way, in this method, the evaluation chip is constructed using two identical single-chip microcontrollers.

[Problem to be solved by the invention]

As mentioned above, when developing an emulator for program development using a conventional semiconductor integrated circuit,
In addition to the design of the integrated circuit itself, evaluation chips and dedicated L
It is necessary to design SI.

Once an evaluation chip has been designed, it can be used as long as the CPU is used. This required a huge amount of man-hours to design.

Regarding the method described in the prior art section, regarding (2), all functions within the family of the dedicated section must be determined at the stage of designing the evaluation chip. This cannot cope with the current development speed of integrated circuits or sudden changes in specifications from customers. If there are many types within a family, it is quite conceivable that this cannot be realized due to process technology problems.

Regarding ■, all data is exchanged between the single-chip microcomputer designated as the mask side (the side with the CPU function) and the single-chip microcomputer specified as the slave side (the side with the dedicated part function). Because this method is only performed on an instruction-by-instruction basis, in other words, this method is only effective when it is known in advance that data will be exchanged by an instruction (for example, a read/write instruction as Ilo). It was completely unsuitable for microcomputers that exchange undetectable asynchronous data (for example, interrupts from a dedicated section to the CPU). Also,
Since all data exchange is managed by the CPU section, a circuit for this purpose is required, which has the disadvantage of complicating the design of the microcomputer.

[Means to solve the problem]

Therefore, in the present invention, for an emulator for a semiconductor integrated circuit consisting of a microcomputer and a dedicated section, we have created a mode in advance in the integrated circuit so that it is not necessary to design a dedicated section LSI that can only be used only for the emulator. Means for inputting a switching signal from outside the semiconductor integrated circuit, and switching input/output of a group of signals input/output from at least two parts inside the semiconductor integrated circuit toward the outside of the semiconductor based on the mode switching signal. an external terminal input/output switching circuit, means for disconnecting the microcomputer and the circuit block based on the mode switching signal, and means for inputting/outputting a group of signals from the microcomputer to the external terminal input/output switching circuit;
Means is provided for newly inputting/outputting the signal that was being input/output from the circuit block to the microcomputer based on the mode switching signal to the external terminal input/output switching circuit.

In this way, the data exchange function between the CPU and the circuit blocks other than the CPU can be cut off, and the data exchange between the CPU and the circuit blocks other than the CPU can be replaced with data exchange between the circuit block and the outside of the integrated circuit.

〔Example〕

FIG. 1 is a block diagram of a semiconductor integrated circuit 1 which is a first embodiment of the present invention. Similar to the integrated circuit described in the prior art section, this integrated circuit also includes a main microcomputer (hereinafter referred to as CPU) 1.0, a dedicated section 3 which is a circuit block with functions different from this CPU, and a CPU. There is a control section 6 that controls whether the input/output of the integrated circuit is input/output to the outside of the integrated circuit or to the dedicated section 3. Furthermore, the bus 2 that is input/output from the dedicated section 3 to the outside of the integrated circuit has the same function.

Next, the operation of the integrated circuit according to the present invention will be described. First, a mode switching signal 9 input from outside the integrated circuit.
Here is a summary of the case when specifies normal mode. At this time, the bus switching section 4 inserted between the control section 6 and the CPU 100 controls the direction of the bus so that data from the CPU 10 is input/output only to the control section 6. Thereby, data is exchanged between the CPU 10 and the dedicated section 3 via the bus 11a.

11b, LLC. Similarly to the bus switching section 4, the external terminal input/output switching section 7 also uses a mode switching signal to transfer only the integrated circuit external input/output data sent and received from the CPU10 via the control section 6 through the bus 11 (1) to the outside of the integrated circuit. The bus is controlled to enable input/output.Bus 8 is a bus for data input/output from CPU10.

When the mode switching signal switches from which normal mode (hereinafter this mode will be referred to as evaluation mode), the following operation will occur.

As the mode switching signal 9 changes to the evaluation mode, the bus switching unit 4 disconnects the CPU 10 and the control unit 6, which were connected in the normal mode. Similarly, the terminal switching unit 7 also switches the bus so that data from the control unit 6 cannot be input or output outside the integrated circuit. Next, by entering the evaluation mode, the bus switching unit 4
,llb.

Buses llb and llc transfer data between the dedicated unit 3 and CPU 10 through 11c.

Bus switching section 4. Switching is made to data exchange with the external end output switching section 7 via the bus 5. As a result, data exchange between the dedicated section 3 and the CPU10 is replaced by data exchange between the dedicated section 3 and the outside of the integrated circuit.

Since these switching sections can be easily designed using current circuit technology, the detailed circuit configuration will not be described here.

Next, an emulator for developing programs for integrated circuits according to the present invention will be explained using FIG. 4.

The basic method of use is to connect the probe 35 to the location where the integrated circuit is originally mounted and use the emulator as a pseudo integrated circuit, similar to the method described in the prior art section.

The configuration of the emulator is as follows. First, the probe 35 and the connection bus 34, and the interface section 33 between the emulator 50 and the outside are the same as those described in the section of the prior art. Similarly to the prior art, an evaluation chip 40 for checking/changing the internal state of the CPU 10 and executing/interrupting the program and a controller 39 for controlling the evaluation chip 40 are also required. In contrast to the prior art, only the integrated circuit 1 according to the invention is required.

The operation will be explained. First, the controller 39 sets the integrated circuit 1 to the above-mentioned evaluation mode using the mode switching signal 9. This allows data to be directly input/output between the outside and the circuit blocks (dedicated section 3 and control section 6) in the integrated circuit 1 through the bus 8. The bus 8 that is input and output from this integrated circuit is connected to the evaluation chip 40, but this makes it possible to
This means that the state in which the CPU 10 and the circuit blocks (dedicated section 3, control section 6) are connected within the integrated circuit can be reproduced within the emulator. That is, by exchanging data between the evaluation chip 40 and the integrated circuit 1 in the evaluation mode, the CPU 10 and the circuit block (dedicated unit 3 and control unit 6) exchange data within the integrated circuit 1 in the normal mode. This means that an equivalent state has been reproduced.

In addition, data input/output from the dedicated section 3 to the outside of the integrated circuit is input/output through the bus 2 similarly to the integrated circuit 1, and
Data input/output from Ul0 to the outside through the bus 8 via the control unit 6 is input/output to the outside of the emulator through the bus 51. As a result, the emulator 50 has a function equivalent to the function of the integrated circuit 1 for inputting and outputting data with the outside of the integrated circuit.

Furthermore, by providing the controller 39 with an evaluation function that controls the evaluation chip 40, etc., the in-circuit
An emulator can be used.

FIG. 5 shows a second embodiment of the invention. Here, the dedicated section in the first embodiment is replaced with a combination of a CPU and a memory.

CPUb61 obtains the instruction by accessing memory 64. Further, CPUal 0 and CPUb61 are connected to buses 11a and 11b as in the first embodiment.

11c. Other components are the same as in the first embodiment.

Regarding the operation, as in the first embodiment, by setting the evaluation mode using the mode switching signal 9, it can be used as an emulator.

〔Effect of the invention〕

The semiconductor integrated circuit according to the present invention is capable of transmitting and receiving data between the built-in microcomputer and other circuit blocks even between the circuit block and the outside of the integrated circuit. The present invention has the feature that it is possible to reduce the number of integrated circuits for emulators required for the development of in-chip emulators, which are essential for the development of in-chip emulators.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a semiconductor integrated circuit according to an embodiment of the present invention, FIG. 2 is a configuration diagram of a conventional semiconductor integrated circuit in which a CPU and a circuit block are combined on the same device, and FIG. 3 is a diagram of a conventional semiconductor integrated circuit shown in FIG. FIG. 4 is a configuration diagram of an emulator for semiconductor integrated circuits, and FIG. 5 is a configuration diagram of an emulator for integrated circuits according to the present invention.
The figure shows a semiconductor integrated circuit according to a second embodiment. 1... Semiconductor integrated circuit according to the first embodiment, 2...
...Bus for exchanging data between the dedicated section 3 and the outside, 3
... Dedicated section which is a circuit block with functions other than CPU10, 4 ... Bus switching section, 5.
...Bus between the bus switching section 4 and the external terminal input/output switching section 7, 6... Whether input/output signals of the CPU10 are sent to the dedicated section 3 or external terminal input/output switching section 7... External terminal input/output switching unit for switching a group of signals input/output to the outside of the integrated circuit, 8... Bus for input/output to the outside, 9...
...Mode switching signal, 10...Microcomputer, lla, llb, lie, 1ld-...
Bus, 20...Construction diagram of a semiconductor integrated circuit explained in the prior art section, 30...Integrated circuit 2
Emulator for 0, 31... Dedicated part LSI, 3
2...Bus, 33...Interface circuit, 34...Cable, 35...Probe, 36...Bus, 37... Control circuit, 38a, 38b... bus, 39...
・Controller, 40...Evaluation chip, 41
...Bus, 42...Bus, 50...
...Configuration diagram of the integrated circuit emulator of the present invention, 5
1... Bus, 60... Semiconductor integrated circuit according to the second embodiment, microcomputer, 62... Bus, 63... Bus, 64... ····memory.

Claims (1)

[Claims] One or more microcomputers and a circuit block having a function different from that of the microcomputer are integrated on the same device and connected to each other, and necessary signals are exchanged between the microcomputer and the circuit block. In a semiconductor integrated circuit, a means for inputting a mode switching signal from outside the semiconductor integrated circuit, and a signal input/output from at least two parts inside the semiconductor integrated circuit to the outside of the semiconductor based on the mode switching signal. an external terminal input/output switching circuit for inputting/outputting groups by switching between them; means for inputting/outputting a signal group from the microcomputer to the external terminal input/output switching circuit; and means for inputting/outputting a signal group from the microcomputer to the external terminal input/output switching circuit; a means for disconnecting the connection, and a signal that has been input/output from the circuit block to the microcomputer based on the mode switching signal is newly routed to the outside of the semiconductor integrated circuit via the external terminal input/output switching circuit. 1. A semiconductor integrated circuit characterized in that a semiconductor integrated circuit is provided with input/output means.