Semiconductor integrated circuit having noise detect circuits detecting noise on power supply nets

Abstract

A processor or a semiconductor integrated circuit which prevents a malfunction caused by noise on power supply nets. A noise detecting circuit which detects noise on power supply nets to a circuit block is arranged in each of a plurality of circuit blocks which performs signal processing, and which performs interruption for preventing a malfunction to the circuit block itself or other circuit blocks relating to this signal processing by a detection signal of each noise detecting circuit.

What is claimed is:  
     
         1 . A semiconductor integrated circuit that includes a plurality of circuit blocks performing signal processing, comprising a noise detecting circuit, which detects noise on power supply nets, inside at least one circuit block, 
 wherein the semiconductor integrated circuit performs interruption for preventing a malfunction to the circuit block itself or another circuit block relating to this signal processing by a detection signal of the noise detecting circuit.    
     
     
         2 . A processor which includes a plurality of logical circuit blocks or memory circuit blocks, comprising: 
 a noise detecting circuit, which detects noise on power supply nets, inside at least one circuit block; and    a circuit block receiving a detection signal of the noise detecting circuit and performing recovery processing to the logical circuit blocks or the memory circuit blocks.    
     
     
         3 . A semiconductor integrated circuit which includes a plurality of circuit blocks performing signal processing, comprising: 
 at least one pair of circuit blocks, which has the same functions each other and operates in parallel; and    a noise detecting circuit, which detects noise on power supply nets, inside at least one of the pair of circuit blocks,    wherein the semiconductor integrated circuit collates signal processing result of the pair of circuit blocks with a detecting signal of the noise detecting circuit, and performs interruption for preventing a malfunction to the circuit block itself or another circuit blocks relating to this signal processing.    
     
     
         4 . The semiconductor integrated circuit according to  claim 1 , 
 wherein the semiconductor integrated circuit makes a circuit block itself or other circuit blocks relating to this signal processing rerun the signal processing by the interruption if a detection signal which shows that noise on power supply nets which induces a malfunction arises from the power supply noise detecting circuit is outputted.    
     
     
         5 . The semiconductor integrated circuit according to  claim 4 , 
 wherein processing in the semiconductor integrated circuit moves to system failure treatment if a detection signal which shows that noise on power supply nets which induces a malfunction arises from the power supply noise detecting circuit is again outputted at the time of the rerun.    
     
     
         6 . The semiconductor integrated circuit according to  claim 1 , 
 wherein the semiconductor integrated circuit suspends an output of signal processing result of the circuit block in the clock cycle concerned by interruption and outputs the signal processing result after the following cycle if a detection signal which shows that noise on power supply nets which induces a malfunction arises from the power supply noise detecting circuit is outputted.    
     
     
         7 . The semiconductor integrated circuit according to  claim 3 , 
 wherein the semiconductor integrated circuit performs the interruption if signal processing results from the pair of circuit blocks differ from each other, or if a detection signal which shows that noise on power supply nets which induces a malfunction arises from the power supply noise detecting circuit is outputted.    
     
     
         8 . The semiconductor integrated circuit according to  claim 1 , 
 wherein the semiconductor integrated circuit supplies electric power to the power supply noise detecting circuit from power supply nets that are shared with the circuit block, and generates a dedicated power supply, which is free from influence of noise from the power supply nets, inside the power supply noise detecting circuit.    
     
     
         9 . The semiconductor integrated circuit according to  claim 1 , 
 wherein the power supply noise detecting circuit comprises a noise detector which detects noise generated in power supply nets of the circuit block, a detection signal holder which holds an output of the noise detector in a predetermined period, and a power supply which generates a dedicated power supply, which is free from influence of noise from the power supply nets, and supplies electric power thereof to the noise detector.    
     
     
         10 . The power supply noise detecting circuit according to  claim 9 , 
 wherein the noise detector comprises: 
 a level shift circuit that shifts a voltage in the power supply nets to a predetermined reference voltage level by making a voltage in the power supply nets as an input; and  
 a level discriminator which judges whether an output of the level shift circuit exceeds a predetermined threshold voltage level.  
   
     
     
         11 . The power supply noise detecting circuit according to  claim 9 , 
 wherein the detection signal holder comprises a dynamic circuit of making a period, when the dynamic circuit operates in response to an output of the noise detector, be an evaluation phase, and making periods except the predetermined period be a precharge phase.    
     
     
         12 . The power supply noise detecting circuit according to  claim 9 , 
 wherein the power supply generates a voltage which fluctuates with following voltage fluctuation of a positive power supply or a negative power supply on the power supply nets.    
     
     
         13 . The power supply noise detecting circuit according to  claim 9 , 
 wherein the power supply noise detecting circuit generates a reset signal from a clock synchronization signal or its delayed signal, and the noise detector and the detection signal holder detect noise in a LOW period of the reset signal, and hold a detection signal, and the power supply charges a dedicated power supply in a HIGH period of the reset signal.