XC2200 Derivatives
System Units (Vol. 1 of 2)
System Control Unit (SCU)
User’s Manual
6-219
V2.1, 2008-08
SCU, V1.13
6.12
SCU Trap Generation
The basic trap structure of the SCU is shown in
Figure 6-33 SCU Trap Structure
If enabled by the corresponding bit in register
, a trap is triggered either by a
pulse on the incoming trap line, or by a software set of the respective bit in register
. The trigger sets the respective flag in register
and is gated to
one of the trap nodes, selected by the node pointer register
The trap flag in register TRAPSTAT can be cleared by software by writing to the
corresponding bit in register
If more than one trap source is connected to the same trap (via register TRAPNP), the
requests are combined to one common line.
Trap Node Assignment
The trap sources of the system can be mapped to three trap nodes by programming the
trap node pointer register TRAPNP. The default assignment of the trap sources to the
nodes and their corresponding control register is listed in
6.12.1
Trap Support
Some of the trap requests are first fed through a sticky flag register in the DMP_M
domain. These flags are set with a trigger and if set trigger the trap generation in the
DMP_1. In this way, the occurrence of a request is registered even when the DMP_1
SCU_Trap_Struct.vsd
TRAPNPn.y
other trap sources to the
same trap
SCU Trap Structure
clear
&
1
TRAPSTAT.x
set
Trap
Event
DMPMIT.x
disable
request
TRAPDIS.x
TRAPSET.x
TRAPCLR.x
to TFR.ACER
SCU
TRQ0
1
1
Reserved
SCU
TRQ1
1
SCU
TRQ2
to TFR.SR1
to TFR.SR0