Electronic apparatus and power supplying method

• Main Authors: KIBA, HIROYUKI, AKUI, SATOSHI, UEDA, TOMOHIRO
• Format: Patent
• Language: English; French; German
• Published: 21.04.2004
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; BASIC ELECTRONIC CIRCUITRY; CALCULATING; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; COMPUTING; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; COUNTING; ELECTRIC DIGITAL DATA PROCESSING; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; GENERATION; INFORMATION STORAGE; PHYSICS; PULSE TECHNIQUE; SEMICONDUCTOR DEVICES; STATIC STORES; SYSTEMS FOR STORING ELECTRIC ENERGY

A control unit (3) supplies power to the standby control and main circuits (21,22), when the mode control unit changes the operation mode of the large-scale integration circuit (LSI) (2) to normal mode from standby mode. The control unit supplies power to only standby control circuit when the operation mode of the LSI is in standby mode. An independent claim is also included for power supply method for electronic apparatus. A system LSI (2) contains a main circuit (22) and an eDRAM (23). The main circuit (22) contains a standby controlling circuit (21) and a CPU. Each circuit block receives power through independent power lines. Power is always supplied to the standby controlling circuit (21). When the system LSI (2) has entered a standby state, power to the main circuit (22) is turned off. Only when the eDRAM (23) is used, power is supplied thereto. The standby controlling circuit (21) and a power controlling circuit (3) control power supplied to each circuit block. When there is no task the CPU has to process, the system LSI (2) enters the standby state from the operation state. When an operation input has taken place with an operating portion or when an input has taken place in an external input, the standby controlling circuit (21) performs a process necessary for waking up the system LSI. Power is supplied to the main circuit (22).