HMS81032E/HMS81032TL
52
Nov. 2001 Ver 2.00
Response Time
The INT1 ~ INT2 edge are latched into IFINT1 ~ IFINT2 at every
machine cycle. The values are not actually polled by the circuitry
until the next machine cycle. If a 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 ex-
ecuted. The DIV itself takes twelve cycles. Thus, a minimum of
twelve complete machine cycles elapse between activation of an
external interrupt request and the beginning of execution of the
first instruction of the service routine.
Figure 14-8 shows interrupt response timings.
Figure 14-8 Interrupt Response Timing Diagram
14.8 Key Scan Input Processing
Key Scan Interrupt is generated by detecting low or high
Input from each Input pin (R0, R1) is one of the sources
which release standby (SLEEP, STOP) mode. Key Scan
ports are all 16bit which are controlled by Standby Mode
Release Register (SMRR0, SMRR1). Key Input is consid-
ered as Interrupt, therefore, KSCNE bit of IEHN should be
set for correct interrupt executing, SLEEP mode and STOP
mode, the rest of executing is the same as that of external
Interrupt. Each SMRR Register bit is allowed for each port
(for Bit= “0”, no Key Input, for Bit= “1”, Key Input avail-
able). At reset, SMRR becomes “00h”. So, there is no Key
Input source.
Figure 14-7 External Interrupt Block Diagram
IFINT1
INT1 pin
INT1 INTERRUPT
IFINT2
INT2 pin
INT2 INTERRUPT
IEDS
[0CBH]
Edge selection
Register
2
2
BT C L
7
6
5
4
3
2
1
0
IED 2H
INITIAL VALUE: --0000--
B
ADDRESS: 0CB
H
IEDS
-
W
Ext. Int. Edge Selection reg.
01: Falling Edge Selection
10: Rising Edge Selection
IED2*
-
-
11: Both Edge Selection
-
W
W
W
IED 2L IE D 1H
IED 1L
01: Falling Edge Selection
10: Rising Edge Selection
IED1*
11: Both Edge Selection
Interrupt
goes
active
Interrupt
latched
Interrupt
processing
Interrupt
routine
8 f
XIN
period
max. 12 f
XIN
period
Содержание HMS81004E
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