MC68HC901P MOTOROLA [Motorola, Inc], MC68HC901P Datasheet - Page 25

• Manufacturer Part Number: MC68HC901P
• Description: Multi-Function Peripheral
• Manufacturer: MOTOROLA [Motorola, Inc]

Interrupt Structure
IV3-IV0 — Interrupt Vector
These bits are supplied by the MFP. They are the binary channel number of the highest
priority channel that is requesting interrupt service.
4.1.3 Vector Register (VR)
This 8-bit register determines the four most-significant bits in the interrupt vector format and
which end-of-interrupt mode is used in a vectored interrupt scheme. The vector register
should be written to before writing to the interrupt mask or enable registers to ensure that
the MFP responds to an interrupt acknowledge cycle with a vector number not in the range
of allowable user vectors. For information refer to Section 4.4.1 Selecting the End-Of-
Interrupt Mode .
4-2
VR REGISTER
RESET
FIELD
ADDR
BIT
IV3
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
V7
7
0
IV2
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
V6
6
0
IV1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
MC68HC901 USER’S MANUAL
V5
5
0
IV0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
V4
4
0
General Purpose Interrupt 7 (I7)
General Purpose Interrupt 6 (I6)
Timer A
Receiver Buffer Full
Receive Error
Transmit Buffer Empty
Transmit Error
Timer B
General Purpose Interrupt 5 (I5)
General Purpose Interrupt 4(I4)
Timer C
Timer D
General Purpose Interrupt 3 (I3)
General Purpose Interrupt 2 (I2)
General Purpose Interrupt 1 (I1)
General Purpose Interrupt 0 (I0)
$17
S
3
0
DESCRIPTION
2
0
*
1
0
*
MOTOROLA
0
0
*