3.5.8
CPU States............................................................................................................................ 51
3.6.1
Program Execution State......................................................................................... 52
3.6.2
Exception-Handling State........................................................................................ 52
3.6.3
Power-Down State................................................................................................... 53
Access Timing and Bus Cycle.............................................................................................. 53
3.7.1
Access to On-Chip Memory (RAM and ROM)...................................................... 53
3.7.2
Access to On-Chip Register Field and External Devices........................................ 55
Block Data Transfer Instruction .............................................................................. 50
3.6
3.7
Section 4. Exception Handling
............................................................................................ 59
4.1
Reset ..................................................................................................................................... 60
4.2
Interrupts............................................................................................................................... 63
4.2.1
Interrupt-Related Registers...................................................................................... 69
4.2.2
External Interrupts................................................................................................... 70
4.2.3
Internal Interrupts.................................................................................................... 71
4.2.4
Interrupt Response Time.......................................................................................... 72
4.2.5
Note on Stack Handling........................................................................................... 73
4.2.6
Deferring of Interrupts............................................................................................. 75
Section 5. I/O Ports
................................................................................................................ 77
5.1
Overview............................................................................................................................... 77
5.2
Port 1..................................................................................................................................... 78
5.3
Port 2..................................................................................................................................... 81
5.4
Port 3..................................................................................................................................... 84
5.5
Port 4..................................................................................................................................... 88
5.6
Port 5..................................................................................................................................... 91
5.7
Port 6..................................................................................................................................... 96
5.8
Port 7.....................................................................................................................................102
5.9
Port 8.....................................................................................................................................104
5.10 Port 9.....................................................................................................................................114
Section 6. 16-Bit Free-Running Timer
..............................................................................123
6.1
Overview...............................................................................................................................123
6.1.1
Features....................................................................................................................123
6.1.2
Block Diagram.........................................................................................................123
6.1.3
Input and Output Pins..............................................................................................125
6.1.4
Register Configuration ............................................................................................125
6.2
Register Descriptions............................................................................................................126
ii