XC886/888CLM
Interrupt System
User’s Manual
5-15
V1.3, 2010-02
Interrupt System, V 1.0
5.5
Interrupt Response Time
Due to an interrupt event of (the various sources of) an interrupt node, its corresponding
request signal will be sampled active at phase 2 in every machine cycle. The value is not
polled by the circuitry until the next machine cycle. If the request is active and conditions
are right for it to be acknowledged, a hardware subroutine call to the requested service
routine will be the next instruction to be executed. The call itself takes two machine
cycles. Thus, a minimum of three complete machine cycles will elapse from activation of
the interrupt request to the beginning of execution of the first instruction of the service
routine as shown in
.
Figure 5-9
Minimum Interrupt Response Time
A longer response time would be obtained if the request is blocked by one of the three
previously listed conditions:
1. If an interrupt of equal or higher priority is already in progress, the additional wait time
will depend on the nature of the other interrupt's service routine.
2. If the instruction in progress is not in its final cycle, the additional wait time cannot be
more than three machine cycles since the longest instructions (MUL and DIV) are
only four machine cycles long. See
.
3. If the instruction in progress is RETI or a write access to registers IEN0, IEN1 or
IP(H), IP1(H), the additional wait time cannot be more than five cycles (a maximum
of one more machine cycle to complete the instruction in progress, plus four machine
cycles to complete the next instruction, if the instruction is MUL or DIV). See
.
Interrupt
request
active/sampled
Interrupt request
polled
(last cycle of
current
instruction)
P2
P1
LCALL
1
st
instruction at
interrupt vector
P2
P1
P2
P1
P2
P1
P2
P1
f
CCLK
Interrupt response time = 3 x machine cycle
*
Содержание XC886CLM
Страница 1: ...User s Manual V1 3 2010 02 Microcontrollers 8 Bit XC886 888CLM 8 Bit Single Chip Microcontroller...
Страница 3: ...User s Manual V1 3 2010 02 Microcontrollers 8 Bit XC886 888CLM 8 Bit Single Chip Microcontroller...
Страница 324: ...XC886 888CLM Serial Interfaces User s Manual 12 52 V1 3 2010 02 Serial Interfaces V 1 0...
Страница 663: ...w w w i n f i n e o n c o m Published by Infineon Technologies AG...