XC886/888CLM
Interrupt System
User’s Manual
5-9
V1.3, 2010-02
Interrupt System, V 1.0
disabled (e.g., software polling is used), its interrupt status flag must be cleared by
software since the core will not be interrupted (and therefore the interrupt acknowledge
is not generated). For the UART module, interrupt status flags RI and TI in register
SCON will not be cleared by the core even when its pending interrupt request is serviced.
The UART module’s interrupt status flags (and hence the pending interrupt request) can
only be cleared by software.
5.1.2
Interrupt Structure 2
Interrupt structure 2 in
applies to Timer 2, Timer 21, UART1, LIN, external
interrupts 2 to 6, ADC, SSC, CCU6, Flash, MDU, CORDIC and MultiCAN interrupt
sources. For this structure, the interrupt status flag does not directly drive the pending
interrupt request, which is latched due to an interrupt event. Further, an additional control
bit IMODE in SYSCON0 register is used to select one of two defined modes of handling
incoming interrupt events.
Figure 5-8
Interrupt Structure 2
If IMODE = 1, an event generated by its corresponding interrupt source will set the status
flag, and in parallel, if the event is enabled for interrupt, generate a pending interrupt
request to the core. If IMODE = 0, an event will set the status flag, but the pending
interrupt request is generated only if the event is enabled for interrupt and the interrupt
node is enabled.
An active pending interrupt request interrupts the core and is automatically cleared by
hardware (the core) once the interrupt node is serviced (interrupt acknowledged); the
status flag remains set and must be cleared by software. A pending interrupt request can
also be cleared by software; the method differs depending on the IMODE bit setting.
If IMODE = 1, only on clearing all interrupt-enabled status flags of the node will indirectly
clear its pending interrupt request. Note that this is not exactly like interrupt structure 1
pending
interrupt
request
AND
interrupt node
enable bit
Event interrupt request
interrupt
acknowledge
(from core)
set/clear
clear
AND
EA bit
to core
FF*
Corresponding
event status
flag
OR
IMODE
NOR
OR
Corresponding
event interrupt
enable bit
Event
occurrence
* Implemented as latch, cannot set by software
All qualified flags of the
interrupt node
*
Содержание XC886CLM
Страница 1: ...User s Manual V1 3 2010 02 Microcontrollers 8 Bit XC886 888CLM 8 Bit Single Chip Microcontroller...
Страница 3: ...User s Manual V1 3 2010 02 Microcontrollers 8 Bit XC886 888CLM 8 Bit Single Chip Microcontroller...
Страница 324: ...XC886 888CLM Serial Interfaces User s Manual 12 52 V1 3 2010 02 Serial Interfaces V 1 0...
Страница 663: ...w w w i n f i n e o n c o m Published by Infineon Technologies AG...