
Semiconductor Group
116
Interrupt System
Figure 8-3
Special Function Register IEN1 (Address 0B8H)
In the following the interrupt sources are discussed individually.
The external interrupts 0 and 1 (INT0 and INT1) can each be either level-activated or negative
transition-activated, depending on bits IT0 and IT1 in register TCON (see figure 8-4). The flags that
actually generate these interrupts are bits IE0 and lE1 in TCON. When an external interrupt is
generated, the flag that generated this interrupt is cleared by the hardware when the service routine
is vectored too, but only if the interrupt was transition-activated. lf the interrupt was level-activated,
then the requesting external source directly controls the request flag, rather than the on-chip
hardware.
The timer 0 and timer 1 interrupts are generated by TF0 and TF1 in register TCON, which are set
by a rollover in their respective timer/counter registers (exception see section 7.3.4 for timer 0 in
mode 3). When a timer interrupt is generated, the flag that generated it is cleared by the on-chip
hardware when the service routine is vectored too.
Bit
Function
EADC
Enables or disables the A/D converter interrupt.
If EADC = 0, the A/D converter interrupt is disabled.
EX2
Enables or disables external interrupt 2/capture/compare interrupt 4.
If EX2 = 0, external interrupt 2 is disabled.
EX3
Enables or disables external interrupt 3/capture/compare interrupt 0.
If EX3 = 0, external interrupt 3 is disabled.
EX4
Enables or disables external interrupt 4/capture/compare interrupt 0.
If EX4 = 0, external interrupt 4 is disabled.
EX5
Enables or disables external interrupt 5/capture/compare interrupt 0.
If EX5 = 0, external interrupt 5 is disabled.
EX6
Enables or disables external interrupt 6/capture/compare interrupt 0
If EX6 = 0, external interrupt 6 is disabled.
EXEN2
Enables or disables the timer 2 external reload interrupt.
EXEN2 = 0 disables the timer 2 external reload interrupt.
The external reload function is not affected by EXEN2.
0BFH 0BEH 0BDH 0BCH 0BBH 0BAH 0B9H
0B8H
EXEN2 SWDT
EX6
EX5
EX4
EX3
EX2
EADC
0B8H
IEN1
This bit is not used for interrupt control.
*
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 ...