XC2200 Derivatives
System Units (Vol. 1 of 2)
Interrupt and Trap Functions
User’s Manual
5-36
V2.1, 2008-08
ICU_X2K, V2.2
5.7
Interrupt Node Sharing
Interrupt nodes may be shared among several module requests if either the requests are
generated mutually exclusively or the requests are generated at a low rate. If more than
one source is enabled in this case, the interrupt handler will first need to determine the
requesting source. However, this overhead is not critical for low rate requests.
This node sharing is either controlled via interrupt sub-node control registers (ISNC)
which provide separate request flags and enable bits for each supported request source,
or via register ISSR, where each bit selects one of two interrupt sources. The interrupt
level used for arbitration is determined by the node control register (… IC).
The specific request flags within ISNC registers must be reset by software, contrary to
the node request bits which are cleared automatically.
Table 5-11
Sub-Node Control Bit Allocation
Interrupt Node
Interrupt Sources
Control
EOPIC
PEC channels 7 … 0
PECISNC
RTC_IC
RTC: overflow of T14, CNT0 … CNT3
RTC_ISNC
CC2_CC16IC
CAPCOM2 request, ERU request 0
ISSR
CC2_CC17IC
CAPCOM2 request, ERU request 1
ISSR
CC2_CC18IC
CAPCOM2 request, ERU request 2
ISSR
CC2_CC19IC
CAPCOM2 request, ERU request 3
ISSR
CC2_CC20IC
CAPCOM2 request, USIC0 request 6
ISSR
CC2_CC21IC
CAPCOM2 request, USIC0 request 7
ISSR
CC2_CC22IC
CAPCOM2 request, USIC1 request 6
ISSR
CC2_CC23IC
CAPCOM2 request, USIC1 request 7
ISSR
CC2_CC24IC
CAPCOM2 request, ERU request 0
ISSR
CC2_CC25IC
CAPCOM2 request, ERU request 1
ISSR
CC2_CC26IC
CAPCOM2 request, ERU request 2
ISSR
CC2_CC27IC
CAPCOM2 request, ERU request 3
ISSR
CC2_CC28IC
CAPCOM2 request, USIC2 request 6
ISSR
CC2_CC29IC
CAPCOM2 request, USIC2 request 7
ISSR