公开(公告)号：DE60034346D1

公开(公告)日：2007-05-24

申请号：DE60034346

申请日：2000-11-03

Applicant: ST MICROELECTRONICS SRL

Inventor： FRANCIS RUSSELL ,  ALIA MICHELE

IPC: G06F1/32

Abstract: Presented is a power down circuit for use in a system on Chip SOC. Within the SOC are several circuit blocks, each of them having a local clock. A system clock is coupled to the circuit blocks and is structured to act as the local clock of selected circuit blocks. A power control manager provides a signal that at least partially determines whether the system clock will act as the local clock for some of the circuit blocks. Within the circuit blocks is a local power control structured to selectively maintain the system clock as the local clock of the block after the local power control receives a signal to shut down the block from the power control manager, if the block is currently busy when the signal to shut down the block is received. Also presented is a method that can be operated using the above system. The method includes generating a system clock signal that is for use as a local clock signal for circuit blocks that have not been shutdown. A shutdown request signal is generated to selectively power down some of the circuit blocks. That shutdown request signal is transmitted to a power down circuit within the circuit block to be shutdown. The power down circuit receives the signal to power down the circuit block, as well as a current status of the block. After an evaluation, the cirucuit block is shut down if the signal to power down is received and the circuit block is presently idle.

公开(公告)号：DE60034345D1

公开(公告)日：2007-05-24

申请号：DE60034345

申请日：2000-11-03

Applicant: ST MICROELECTRONICS SRL

Inventor： ALIA MICHELE ,  CARRANO MICHELE ,  PISTRITTO CARMELO

IPC: G06F1/32

Abstract: Presented is a power down circuit for use in a System on Chip SOC. Within the SOC are several circuit blocks, each of them having a local clock. A system clock is coupled to the circuit blocks and is structured to act as the local clock of selected circuit blocks. A power control manager provides a signal that at least partially determines whether the system clock will act as the local clock for some of the circuit blocks. Within the circuit blocks is a shutdown circuit that selectively prevents the system clock from acting as the local clock in those circuit blocks that receive the shutdown signal, but the shutdown circuit only operates after both the signal to shut down is received from the power control manager and after the circuit block has, in fact, shut down. Also presented is a method that can be operated using the above system. The method includes generating a system clock signal that is for use as a local clock signal for circuit blocks that have not been shutdown. A shutdown request signal is generated to selectively power down some of the circuit blocks. That shutdown request signal is transmitted to a power down circuit within the circuit block to be shutdown. Once the block to be shutdown receives the shutdown request signal, it finishes any necessary circuit operations, and then shuts down the circuit block. Once the circuit block has shut down, a shutdown acknowledgement signal is generated, and, when this signal is received at the power down circuit within the circuit block, the system clock signal is disconnected from the local clock signal.