Abstract:
The present invention realizes an efficient superscalar instruction issue and low power consumption at an instruction set including instructions with prefixes. An instruction fetch unit is adopted which determines whether an instruction code is of a prefix code or an instruction code other than it, and outputs the result of determination and the 16-bit instruction code. Along with it, decoders each of which decodes the instruction code, based on the result of determination, and decoders each of which decodes the prefix code, are disposed separately. Further, a prefix is supplied to each decoder prior to a fixed-length instruction code like 16 bits modified with it. A fixed-length instruction code following the prefix code is supplied to each decoder of the same pipeline as the decoder for the prefix code.
Abstract:
A semiconductor device including: a first slave device; a first master device outputting a first request control signal and a first access address signal; a second master device outputting a second request control signal and a second access address signal; a system bus connected to the first slave device, the first master device and the second master device, and selecting and outputting either the first request control signal or the second request control signal when the first request control signal is outputted from the first master device and the second request control signal is outputted from the second master device; and a range setting register holding an address range of which an access of the first master device is permitted, wherein the system bus blocks the first request control signal if the first access address signal is out of the address range.
Abstract:
A semiconductor data processor has a first memory(6) constituting a cache memory, a second memory(20) capable of being a cacheable area or a non-cacheable area by the first memory, and a read buffer(12) capable of carrying out an operation for outputting data corresponding to a read access when the second memory is read accessed as the non-cacheable area. The designation of the cacheable area and the non-cacheable area for the second memory is determined by the designation of a cacheable area or a non-cacheable area for a memory space to which the second memory is mapped. The designation may be carried out in the operation mode of the data processor or by setting a control register, for example.
Abstract:
This invention is intended to reduce the hypervisor overhead. In the data processor disclosed herein, when a device driver calls for access to a control register to activate a process of a dedicated controlled peripheral device, the access is handled directly without intervention of processing by the hypervisor. When an interrupt is generated from a dedicated controlled peripheral device, a process is directly initiated by the device driver of the operating system governing the peripheral device without intervention of processing by the hypervisor. By implementing this manner of control in the processor, it becomes possible to carry out peripheral device control without intervention of processing by the hypervisor. Thereby, the hypervisor overhead is alleviated.
Abstract:
A data processor includes: a central processing unit (CPU), in which a plurality of virtual machines (101), each running an application program under controls of different operating systems, and a virtual machine manager (190) for controlling the plurality of virtual machines are selectively arranged according to information set in mode registers (140, 150, 151); and a resource access management module (110) for managing access to hardware resource available for the plurality of virtual machines. The resource access management module accepts, as inputs, the information set in the mode registers and access control information of the central processing unit to the hardware resource, compares the information thus input with information set in a control register, and controls whether or not to permit access to the hardware resource in response to the access control information. As a result, redesign involved in changes in system specifications can be reduced, and a malfunction owing to resource contention can be prevented. The invention contributes to increase of security.
Abstract:
A semiconductor device including: a first slave device; a first master device outputting a first request control signal and a first access address signal; a second master device outputting a second request control signal and a second access address signal; a system bus connected to the first slave device, the first master device and the second master device, and selecting and outputting either the first request control signal or the second request control signal when the first request control signal is outputted from the first master device and the second request control signal is outputted from the second master device; and a range setting register holding an address range of which an access of the first master device is permitted, wherein the system bus blocks the first request control signal if the first access address signal is out of the address range.
Abstract:
The present invention realizes an efficient superscalar instruction issue and low power consumption at an instruction set including instructions with prefixes. An instruction fetch unit is adopted which determines whether an instruction code is of a prefix code or an instruction code other than it, and outputs the result of determination and the 16-bit instruction code. Along with it, decoders each of which decodes the instruction code, based on the result of determination, and decoders each of which decodes the prefix code, are disposed separately. Further, a prefix is supplied to each decoder prior to a fixed-length instruction code like 16 bits modified with it. A fixed-length instruction code following the prefix code is supplied to each decoder of the same pipeline as the decoder for the prefix code.
Abstract:
The data processor can form a system including a combination of two or more operating systems running in parallel, which achieves a higher data transfer rate between operating systems and the increase in system performance without impairing the system reliability. In the system, data transfer between domains is performed in an enhanced access mode as well as an access mode in which an access from a domain manager having control of domains is handled as one from the domain manager. The enhanced access mode is arranged by enhancing, to a CPU scale, an access mode in which an access from the domain manager is treated as an access from a software program working on a domain, and the software program of domain manager transfers data between the domains. For example, in case that the domain manager performs data transfer between domains in the enhanced access mode, a read access from the domain manager is disguised as a read access from a first domain, and a write access from the domain manager is disguised as a write access from a second domain.
Abstract:
This invention is intended to reduce the hypervisor overhead. In the data processor disclosed herein, when a device driver calls for access to a control register to activate a process of a dedicated controlled peripheral device, the access is handled directly without intervention of processing by the hypervisor. When an interrupt is generated from a dedicated controlled peripheral device, a process is directly initiated by the device driver of the operating system governing the peripheral device without intervention of processing by the hypervisor. By implementing this manner of control in the processor, it becomes possible to carry out peripheral device control without intervention of processing by the hypervisor. Thereby, the hypervisor overhead is alleviated.
Abstract:
A semiconductor device including: a first slave device; a first master device outputting a first request control signal and a first access address signal; a second master device outputting a second request control signal and a second access address signal; a system bus connected to the first slave device, the first master device and the second master device, and selecting and outputting either the first request control signal or the second request control signal when the first request control signal is outputted from the first master device and the second request control signal is outputted from the second master device; and a range setting register holding an address range of which an access of the first master device is permitted, wherein the system bus blocks the first request control signal if the first access address signal is out of the address range.