AT90S8515

Manufacturer Part NumberAT90S8515
Description8-bit microcontroller with 8K bytes in-system programmable flash, 2.7-6.0V
ManufacturerATMEL Corporation
AT90S8515 datasheet
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Page 21
22
Page 22
23
Page 23
24
Page 24
25
Page 25
26
Page 26
27
Page 27
28
Page 28
29
Page 29
30
Page 30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
Page 26/112:

General Interrupt Mask

Download datasheet (3Mb)Embed
PrevNext

General Interrupt Mask

Register – GIMSK
General Interrupt Flag
Register – GIFR
AT90S8515
26
interrupt. Some of the interrupt flags can also be cleared by writing a logical “1” to the
flag bit position(s) to be cleared.
If an interrupt condition occurs when the corresponding interrupt enable bit is cleared
(zero), the interrupt flag will be set and remembered until the interrupt is enabled or the
flag is cleared by software.
If one or more interrupt conditions occur when the global interrupt enable bit is cleared
(zero), the corresponding interrupt flag(s) will be set and remembered until the global
interrupt enable bit is set (one) and will be executed by order of priority.
Note that external level interrupt does not have a flag and will only be remembered for
as long as the interrupt condition is active.
Bit
7
6
5
$3B ($5B)
INT1
INT0
Read/Write
R/W
R/W
R
Initial Value
0
0
0
• Bit 7 – INT1: External Interrupt Request 1 Enable
When the INT1 bit is set (one) and the I-bit in the Status Register (SREG) is set (one),
the external pin interrupt is enabled. The Interrupt Sense Control1 bits 1/0 (ISC11 and
ISC10) in the MCU general Control Register (MCUCR) define whether the external
interrupt is activated on rising or falling edge of the INT1 pin or is level-sensed. Activity
on the pin will cause an interrupt request even if INT1 is configured as an output. The
corresponding interrupt of External Interrupt Request 1 is executed from program mem-
ory address $002. See also “External Interrupts”.
• Bit 6 – INT0: External Interrupt Request 0 Enable
When the INT0 bit is set (one) and the I-bit in the Status Register (SREG) is set (one),
the external pin interrupt is enabled. The Interrupt Sense Control0 bits 1/0 (ISC01 and
ISC00) in the MCU general Control Register (MCUCR) define whether the external
interrupt is activated on rising or falling edge of the INT0 pin or is level-sensed. Activity
on the pin will cause an interrupt request even if INT0 is configured as an output. The
corresponding interrupt of External Interrupt Request 0 is executed from program mem-
ory address $001. See also “External Interrupts”.
• Bits 5..0 – Res: Reserved Bits
These bits are reserved bits in the AT90S8515 and always read as zero.
Bit
7
6
5
$3A ($5A)
INTF1
INTF0
Read/Write
R/W
R/W
R
Initial Value
0
0
0
• Bit 7 – INTF1: External Interrupt Flag1
When an edge on the INT1 pin triggers an interrupt request, the corresponding interrupt
flag, INTF1 becomes set (one). If the I-bit in SREG and the corresponding interrupt
enable bit, INT1 in GIMSK is set (one), the MCU will jump to the interrupt vector. The
flag is cleared when the interrupt routine is executed. Alternatively, the flag can be
cleared by writing a logical “1” to it. This flag is always cleared when INT1 is configured
as level interrupt.
4
3
2
1
R
R
R
R
0
0
0
0
4
3
2
1
R
R
R
R
0
0
0
0
0
GIMSK
R
0
0
GIFR
R
0
0841G–09/01