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Semiconductor Group
112
Interrupt System
8
Interrupt System
The SAB 80C515/80C535 provides 12 interrupt sources with four priority levels.
Five interrupts can be generated by the on-chip peripherals (i.e. timer 0, timer 1, timer 2, compare
timer, serial interface and A/D converter), and seven interrupts may be triggered externally (see
figure 8.1).
8.1
Interrupt Structure
A common mechanism is used to generate the various interrupts, each source having its own
request flag(s) located in a special function register (e.g. TCON, IRCON, SCON). Provided that the
peripheral or external source meets the condition for an interrupt, the dedicated request flag is set,
whether an interrupt is enabled or not. For example, each timer 0 overflow sets the corresponding
request flag TF0. lf it is already set, it retains a one (1). But the interrupt is not necessarily serviced.
Now each interrupt requested by the corresponding flag can individually be enabled or disabled by
the enable bits in SFR’s IEN0, IEN1 (see figure 8-2, 8-3). This determines whether the interrupt will
actually be performed. In addition, there is a global enable bit for all interrupts which, when cleared,
disables all interrupts independent of their individual enable bits.
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Summary of Contents for SAB 80515 Series
Page 9: ...Semiconductor Group 9 Introduction Figure 1 2 Block Diagram ...
Page 12: ...Semiconductor Group 12 Fundamental Structure Figure 2 1 Detailed Block Diagram ...
Page 18: ...Semiconductor Group 18 Central Processing Unit Figure 3 1 Fetch Execute Sequence ...
Page 73: ...Semiconductor Group 73 On Chip Peripheral Components Figure 7 25 A D Converter Block Diagram ...
Page 83: ...Semiconductor Group 83 On Chip Peripheral Components Figure 7 33 a Timer 2 Block Diagram ...
Page 215: ...Device Specifications Semiconductor Group 215 ...
Page 217: ...Device Specifications Semiconductor Group 217 Pin Configuration P LCC 68 ...
Page 219: ...Device Specifications Semiconductor Group 219 Logic Symbol ...
Page 226: ...Device Specifications Semiconductor Group 226 Figure 1 Block Diagram ...
Page 229: ...Device Specifications Semiconductor Group 229 Figure 2 Memory Address Spaces ...
Page 239: ...Device Specifications Semiconductor Group 239 Figure 4 Block Diagram of the A D Converter ...
Page 241: ...Device Specifications Semiconductor Group 241 Figure 5 Interrupt Request Sources ...
Page 242: ...Device Specifications Semiconductor Group 242 Figure 6 Interrupt Priority Level Structure ...