
74/324
ST92F120 - INTERRUPTS
5.6 EXTERNAL INTERRUPTS
5.6.1 Standard External Interrupts
The standard ST9 core contains 8 external inter-
rupts sources grouped into four pairs.
Table 18. External Interrupt Channel Grouping
Each source has a trigger control bit TEA0,..TED1
(R242,EITR.0,..,7 Page 0) to select triggering on
the rising or falling edge of the external pin. If the
Trigger control bit is set to “1”, the corresponding
pending bit IPA0,..,IPD1 (R243,EIPR.0,..,7 Page
0) is set on the input pin rising edge, if it is cleared,
the pending bit is set on the falling edge of the in-
put pin. Each source can be individually masked
through
the
corresponding
IMA0,..,IMD1 (EIMR.7,..,0). See
Figure 37
.
Figure 36. Priority Level Examples
control
bit
The priority level of the external interrupt sources
can be programmed among the eight priority lev-
els with the control register EIPLR (R245). The pri-
ority level of each pair is software defined using
the bits PRL2,PRL1. For each pair, the even chan-
nel (A0,B0,C0,D0) of the group has the even prior-
ity level and the odd channel (A1,B1,C1,D1) has
the odd (lower) priority level.
Figure 36
shows an example of priority levels.
Figure 37
gives an overview of the external inter-
rupts and vectors.
– The source of interrupt channel A0 can be se-
lected between the external pin INT0 or the
Timer/Watchdog peripheral using the IA0S bit in
the EIVR register (R246 Page 0).
– The source of interrupt channel A1 can be se-
lected between the external pin INT1 or the
Standard Timer using the INTS bit in the STC
register (R232 Page 11).
– The source of the interrupt channel B0 can be
selected between the external pin INT2 or the
on-chip Extended Function Timer 0 using the
EFTIS bit in the CR3 register (R255 Page 28).
– The source of interrupt channel B1 can be se-
lected between external pin INT3 or the on-chip
Extended Function Timer 1 using the EFTIS bit
in the CR3 register (R255 Page 29).
– The source of the interrupt channel C0 can be
selected between external pin INT4 or the On-
chip EEPROM/Flash Memory using bit FEIEN
in the ECR register (Address 224001h).
– The source of interrupt channel C1 can be se-
lected between external pin INT5 or the on-chip
SPI using the SPIS bit in the SPCR0 register
(R241 Page 7).
– The source of interrupt channel D0 can be se-
lected between external pin INT6 or the Reset
and Clock Unit RCCU using the INT_SEL bit in
the CLKCTL register (R240 Page 55).
– The source of interrupt channel D1 selected be-
tween the NMI pin and the WUIMU Wakeup/In-
terrupt Lines using the ID1S bit in the WUCRTL
register (R248 Page 9).
Caution
: When using external interrupt channels
shared by both external interrupts and peripherals,
special care must be taken to configure control
registers both for peripheral and interrupts.
External
Interrupt
Channel
I/O Port Pin
WKUP[0:15]
INTD1
P8[1:0] P7[7:5]
P6[7,5] P5[7:5, 2:0] P4[7,4]
P6.1
P6.3
P6.2
P6.3
P6.2
P6.0
P6.0
INT6
INT5
INT4
INT3
INT2
INT1
INT0
INTD0
INTC1
INTC0
INTB1
INTB0
INTA1
INTA0
1
0
0
1
0
0
1
PL2D PL1D PL2C PL1C PL2B PL1B PL2A PL1A
INT.D1:
INT.C1: 001=1
INT.D0:
SOURCE
PRIORITY
PRIORITY
SOURCE
INT.A0: 010=2
INT.A1: 011=3
INT.B1: 101=5
INT.B0: 100=4
INT.C0: 000=0
EIPLR
VR000151
0
100=4
101=5
Channel
Internal Interrupt Source
External
Interrupt
Source
INT0
INT1
INT2
INT3
INT4
INT5
INT6
INTA0
INTA1
INTB0
INTB1
INTC0
INTC1
INTD0
INTD1
Timer/Watchdog
Standard Timer
Extended Function Timer 0
Extended Function Timer 1
EEPROM/Flash
SPI Interrupt
RCCU
Wake-up Management Unit
9