7542 Group
Rev.3.03
Jul 11, 2008
Page 25 of 117
REJ03B0006-0303
Interrupts
The 7542 Group interrupts are vector interrupts with a fixed prior-
ity scheme, and generated by 16 sources among 18 sources: 6
external, 11 internal, and 1 software.
The interrupt sources, vector addresses(1) , and interrupt priority
are shown in Table 8.
Each interrupt except the BRK instruction interrupt has the inter-
rupt request bit and the interrupt enable bit. These bits and the
interrupt disable flag (I flag) control the acceptance of interrupt re-
quests. Figure 23 shows an interrupt control diagram.
An interrupt request is accepted when all of the following condi-
tions are satisfied:
Interrupt disable flag.................................“0”
Interrupt request bit...................................“1”
Interrupt enable bit....................................“1”
Though the interrupt priority is determined by hardware, priority
processing can be performed by software using the above bits
and flag.
Table 8 Interrupt vector addresses and priority
Vector addresses (Note 1)
High-order
Priority
Low-order
Interrupt request generating conditions
Remarks
Interrupt source
FFFC16
FFFA16
FFF816
FFF616
FFF416
FFF216
FFF016
FFEE16
FFEC16
FFEA16
FFE816
FFE616
FFE416
FFE216
FFE016
FFDE16
FFDC16
FFFD16
FFFB16
FFF916
FFF716
FFF516
FFF316
FFF116
FFEF16
FFED16
FFEB16
FFE916
FFE716
FFE516
FFE316
FFE116
FFDF16
FFDD16
Notes1: Vector addresses contain internal jump destination addresses.
2: Reset function in the same way as an interrupt with the highest priority.
3: Key-on wakeup interrupt and UART1 bus collision detection interrupt can be enabled by setting of interrupt source set register. The occurrence of
these interrupts are discriminated by interrupt source discrimination register.
4: A/D conversion interrupt and Timer 1 interrupt can be enabled by setting of interrupt source set register. The occurrence of these interrupts are dis-
criminated by interrupt source discrimination register.
Non-maskable
Valid only when serial I/O1 is selected
Valid only when serial I/O2 is selected
External interrupt
(active edge selectable)
External interrupt
(active edge selectable)
External interrupt
(valid at falling edge)
When UART1 bus collision detection
interrupt is enabled.
External interrupt
(active edge selectable)
External interrupt
(active edge selectable)
External interrupt
(active edge selectable)
Compare interrupt source is selected.
STP release timer underflow
Non-maskable software interrupt
At reset input
At completion of serial I/O1 data receive
At completion of serial I/O1 transmit shift
or when transmit buffer is empty
At completion of serial I/O2 data receive
At completion of serial I/O2 transmit shift
or when transmit buffer is empty
At detection of either rising or falling edge
of INT0 input
At detection of either rising or falling edge
of INT1 input
At falling of conjunction of input logical
level for port P0 (at input)
At detection of UART1 bus collision
detection
At detection of either rising or falling edge
of CNTR0 input
At detection of either rising or falling edge
of Capture 0 input
At detection of either rising or falling edge
of Capture 1 input
At compare matched
At timer X underflow
At timer A underflow
At timer B underflow
At completion of A/D conversion
At timer 1 underflow
At BRK instruction execution
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Reset (Note 2)
Serial I/O1 receive
Serial I/O1 transmit
Serial I/O2 receive
Serial I/O2 transmit
INT0
INT1
Key-on wake-up/
UART1 bus
collision detection
(Note 3)
CNTR0
Capture 0
Capture 1
Compare
Timer X
Timer A
Timer B
A/D conversion/
Timer 1 (Note 4)
BRK instruction