Raven Interrupt Controller Implementation
http://www.motorola.com/computer/literature 2-65
2
Spurious Vector Register
VECTOR This vector is returned when the Interrupt Acknowledge
register is read during a spurious vector fetch.
Timer Frequency Register
This register is used to report the frequency (in Hz) of the clock source for
the global timers. Following reset, this register contains zero. system
initialization code must initialize this register to one-eighth the MPIC
clock frequency. For the Raven implementation of MPIC, a typical value
would be $7de290 which is 66/8 MHz or 8.25 MHz.
Offset $010E0
Bit 3
1
3
0
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
1
0
9876543210
Name VECTOR
Operation RRRR/W
Reset $00 $00 $00 $FF
Offset $010F0
Bit 3
1
3
0
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
1
0
9876543210
Name TIMER FREQUENCY
Operation R/W
Reset $00000000