MC68000 MOTOROLA [Motorola, Inc], MC68000 Datasheet - Page 73

• Manufacturer Part Number: MC68000
• Manufacturer: MOTOROLA [Motorola, Inc]

MOTOROLA
1. FORMULATE 8-BIT VECTOR
2. MULTIPLY BY 4 TO GET ADDRESS
3. READ 32-BIT VALUE AT $2B4 AND JUMP
7 (Highest)
6
5
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
3
2
1 (Lowest)
Priority
Level
Figure 3-4. SCC1 Vector Calculation Example
1 0 1 0 1 1 0 1 0 0 = $2B4
Table 3-5. Encoding the Interrupt Vector
V7–V5
1 0 1
$2B4
$2B6
Vector
10111
10110
01111
01110
01101
01100
01011
01010
01001
01000
00111
00110
00101
00100
00011
00010
00001
00000
10001
MC68302 USER’S MANUAL
5-BIT VECTOR
None
None
None
5-Bit
0007
0302
0 1 1 0 1
External Device
External Device
External Device
General-Purpose Interrupt 3 (PB11)
General-Purpose Interrupt 2 (PB10)
SCC1
SDMA Channels Bus Error
IDMA Channel
SCC2
Timer 1
SCC3
General-Purpose Interrupt 1 (PB9)
Timer 2
SCP
Timer 3
SMC1
SMC2
General-Purpose Interrupt 0 (PB8)
Error
External Device
External Device
External Device
V7–V5 PROGRAMMED BY SOFTWARE IN
THE GIMR.
5-BIT VECTOR FROM TABLE 3-4.
INTERRUPT HANDLER BEGINS AT
$070302 (24-BIT ADDRESSES ARE USED
ON THE M68000).
NOTE THAT $2B4 IS IN THE USER
INTERRUPT VECTOR AREA OF THE
EXCEPTION VECTOR TABLE. V7–V5 WAS
PURPOSELY CHOSEN TO CAUSE THIS.
Interrupt Source
System Integration Block (SIB)
3-23