M16C User Manual.pdf

4.2.1 Interrupt Enable Flag ...........................................................................................................4934.2.2 Interrupt Request Bit ............................................................................................................4934.2.3 Changing the Interrupt Control Register ..............................................................................4944.2.4 Interrupt Priority Level Select Bit and Processor Interrupt Priority Level (IPL) ....................4954.3 Interrupt Sequence .....................................................................................................................4964.3.1 Interrupt Response Time .....................................................................................................4964.3.2 Variation of IPL when Interrupt Request is Accepted ..........................................................4974.3.3 Saving Registers ..................................................................................................................4984.4 Returning from an Interrupt Routine ...........................................................................................5004.5 Interrupt Priority ..........................................................................................................................5004.6 Multiple Interrupts .......................................................................................................................5024.7 Precautions for Interrupts ...........................................................................................................504Chapter 5 External Buses __________________________________5.1 Overview of External Buses ........................................................................................................5085.2 Data Access ................................................................................................................................5095.2.1 Data Bus Width ....................................................................................................................5095.2.2 Chip Selects and Address Bus ............................................................................................5105.2.3 Bus Types ...........................................................................................................................5115.2.4 R/W Modes .........................................................................................................................5115.3 Memory Space Expansion Features ...........................................................................................5125.3.1 Normal Mode .......................................................................................................................5135.3.2 Memory Space Expansion Mode 1 ......................................................................................5145.3.3 Memory Space Expansion Mode 2 .....................................................................................5155.4 Connection Examples .................................................................................................................5215.4.1 16-bit Memory to 16-bit Width Data Bus Connection Example ............................................5215.4.2 8-bit Memory to 16-bit Width Data Bus Connection Example..............................................5225.4.3 8-bit Memory to 8-bit Width Data Bus Connection Example...............................................5245.4.4 Two 8-bit and 16-Bit Memory to 16-Bit Width Data Bus Connection Example ....................5255.4.5 16-bit Width Data Bus Connection Example in Memory Space Expansion Mode 1 ............5265.4.6 8-bit Width Data Bus Connection Example in Memory Space Expansion Mode 1 .............5275.4.7 8-bit Width Data Bus Connection Example in Memory Space Expansion Mode 2 .............5285.4.8 Chip Selects and Address Bus ............................................................................................5295.5 Connectable Memories ...............................................................................................................5305.5.1 Operation Frequency and Access Time ..............................................................................530