Rev. 5.0, 09/04, page vii of xviii
5.2
Register Descriptions........................................................................................................86
5.2.1
System Control Register (SYSCR)......................................................................86
5.2.2
Interrupt Priority Registers A and B (IPRA, IPRB).............................................87
5.2.3
IRQ Status Register (ISR)....................................................................................94
5.2.4
IRQ Enable Register (IER)..................................................................................95
5.2.5
IRQ Sense Control Register (ISCR) ....................................................................96
Interrupt Sources...............................................................................................................97
5.3.1
External Interrupts ...............................................................................................97
5.3.2
Internal Interrupts ................................................................................................98
5.3.3
Interrupt Vector Table .........................................................................................98
Interrupt Operation............................................................................................................102
5.4.1
Interrupt Handling Process ..................................................................................102
5.4.2
Interrupt Sequence...............................................................................................107
5.4.3
Interrupt Response Time......................................................................................108
Usage Notes......................................................................................................................109
5.5.1
Contention between Interrupt and Interrupt-Disabling Instruction......................109
5.5.2
Instructions that Inhibit Interrupts .......................................................................110
5.5.3
Interrupts during EEPMOV Instruction Execution..............................................110
5.3
5.4
5.5
Section 6 Bus Controller....................................................................................111
6.1
Overview...........................................................................................................................111
6.1.1
Features................................................................................................................111
6.1.2
Block Diagram.....................................................................................................113
6.1.3
Pin Configuration.................................................................................................114
6.1.4
Register Configuration.........................................................................................115
6.2
Register Descriptions........................................................................................................116
6.2.1
Bus Width Control Register (ABWCR)...............................................................116
6.2.2
Access State Control Register (ASTCR) .............................................................117
6.2.3
Wait Control Registers H and L (WCRH, WCRL)..............................................117
6.2.4
Bus Release Control Register (BRCR) ................................................................121
6.2.5
Bus Control Register (BCR)................................................................................122
6.2.6
Chip Select Control Register (CSCR)..................................................................126
6.2.7
DRAM Control Register A (DRCRA).................................................................127
6.2.8
DRAM Control Register B (DRCRB) .................................................................129
6.2.9
Refresh Timer Control/Status Register (RTMCSR) ............................................131
6.2.10 Refresh Timer Counter (RTCNT)........................................................................133
6.2.11 Refresh Time Constant Register (RTCOR) .........................................................133
6.2.12 Address Control Register (ADRCR)....................................................................134
6.3
Operation ..........................................................................................................................135
6.3.1
Area Division.......................................................................................................135
6.3.2
Bus Specifications................................................................................................137
6.3.3
Memory Interfaces...............................................................................................138
6.3.4
Chip Select Signals..............................................................................................139