INT Interrupt
Unde
deeopmen
Preliminary Specifications REV.E
Specifications in this manual are tentative and subject to change.
Mitsubishi microcomputers
M30220 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
45
______
________
Of interrupt control registers, 0058
16
is used both as timer A3 and external interrupt INT4 input control register, and
0059
16
is used both as timer A4 and as external interrupt INT5 input control register. Use the interrupt request cause
select bits - bits 6 and 7 of the interrupt request cause select register 1 (address 035F
16
) - to specify which interrupt
request cause to select. When INT4 is selected as an interrupt source, the input port for it can be selected by bits 0 and
1 of the interrupt source select register 0 (address 035E
16
). Similarly, when INT5 is selected as an interrupt source, the
input port for it can be selected by bits 2 and 3 of the interrupt source select register 0 (address 035E
16
). After having
set an interrupt request cause and interrupt input ports, be sure to set the corresponding interrupt request bit to “0”
before enabling an interrupt.
Either of the interrupt control registers - 0058
16
, 0059
16
- has the polarity-switching bit. Be sure to set this bit to “0” to
select an timer as the interrupt request cause.
As for external interrupt input, an interrupt can be generated both at the rising edge and at the falling edge by setting
“1” in the INTi interrupt polarity switching bit of the interrupt request cause select register 1 (035F
16
). To select two
edges, set the polarity switching bit of the corresponding interrupt control register to ‘falling edge’ (“0”).
When INT4 input pin select bits = “11”, INT4 interrupt polarity switching bit = “0”, and polarity select bit = “1” of the INT4
interrupt control register, an interrupt is generated by a rising edge on the input port when the exclusive pin is “H”, as
shown by “Single edge, Rise” in Figure 1.10.12. When the exclusive pin is “H”, interrupts can only be generated by an
active transition on a single edge. The same applies to INT5.
Figure 1.10.10 shows the interrupt request cause select register.
________
Figure 1.10.10. Interrupt request cause select registers 0, 1
Interrupt request cause select register 1
AAA
Bit name
Function
Bit
IFSR10
R
Symbol
IFSR1
Address
035F
16
When reset
00
16
b7
b6
b5
b4
b3
b2
b1
b0
AAA
INT0 interrupt polarity
switching bit
0 : Timer A3
0 : Timer A4
0 : One edge
1 : Two edges
0 : One edge
0 : One edge
1 : Two edges
0 : One edge
0 : One edge
INT1 interrupt polarity
switching bit
INT2 interrupt polarity
switching bit
INT3 interrupt polarity
INT4 interrupt polarity
INT5 interrupt polarity
switching bit
0 : One edge
1 : Two edges
Interrupt request cause
Interrupt request cause
IFSR11
IFSR12
IFSR13
IFSR14
IFSR15
IFSR16
IFSR17
A
AA
AA
AA
AA
AA
A
A
A
A
A
A
A
A
Interrupt request cause select register 0
AAA
Bit name
Function
IFSR00
W
R
Symbol
IFSR0
Address
035E
16
When reset
X0000000
2
b7
b6
b5
b4
b3
b2
b1
b0
AAA
INT4 input pin select bit
00: No INT4 input
01: P4
6
input enabled
10: P4
7
input enabled
11: P4
6
, P4
7
input enabled
0 : Timer A5
1 :
Bus collision detection
INT5 input pin select bit
Interrupt request cause
Reserved bit
Must always be set to “0”
IFSR01
IFSR02
IFSR03
IFSR04
AA
AA
AA
AA
AA
00: No INT5 input
01: P8
0
input enabled
10: P8
1
input enabled
11: P8
0
, P8
1
input enabled
Nothing is assigned.
In an attempt to write to this bit, write “0”. The value, if read, turns out
to be
indeterminate.
AA