MOTOROLA
Chapter 4. System Interface Unit (SIU)
4-13
Part II. ConÞguration and Reset
4.2.2.3 Highest Priority Interrupt
In addition to the FCC/MCC/SCC relative priority option, SICR[HP] can be used to specify
one interrupt source as having highest priority. This interrupt remains within the same
interrupt level as the other interrupt controller interrupts, but is serviced before any other
interrupt in the table.
If the highest priority feature is not used, select the interrupt request in XSIU1 to be the
highest priority interrupt; the standard interrupt priority order is used. SICR[HP] can be
updated dynamically to allow the user to change a normally low priority source into a high
priority-source for a certain period.
4.2.3 Masking Interrupt Sources
By programming the SIU mask registers, SIMR_H and SIMR_L, the user can mask
interrupt requests to the core. Each SIMR bit corresponds an interrupt source. To enable an
interrupt, write a one to the corresponding SIMR bit. When a masked interrupt source has
a pending interrupt request, the corresponding SIPNR bit is set, even though the interrupt
is not generated to the core. The user can mask all interrupt sources to implement a polling
interrupt servicing scheme.
When an interrupt source has multiple interrupting events, the user can individually mask
these events by programming a mask register within that block. Table 4-2 shows which
interrupt sources have multiple interrupting events. Figure 4-9 shows an example of how
the masking occurs, using an SCC as an example.
Summary of Contents for MPC8260 PowerQUICC II
Page 1: ...MPC8260UM D 4 1999 Rev 0 MPC8260 PowerQUICC II UserÕs Manual ª ª ...
Page 66: ...lxvi MPC8260 PowerQUICC II UserÕs Manual MOTOROLA ...
Page 88: ...1 18 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part I Overview ...
Page 120: ...2 32 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part I Overview ...
Page 138: ...Part II iv MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part II Configuration and Reset ...
Page 184: ...4 46 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part II ConÞguration and Reset ...
Page 202: ...Part III vi MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 266: ...8 34 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 382: ...10 106 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 392: ...11 10 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 430: ...Part IV viii MOTOROLA Part IV Communications Processor Module ...
Page 490: ...14 36 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 524: ...17 10 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 556: ...18 32 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 584: ...19 28 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 632: ...21 24 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 652: ...22 20 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 668: ...23 16 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 758: ...27 28 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 780: ...28 22 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 874: ...29 94 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 920: ...31 18 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 980: ...A 4 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Appendixes ...
Page 1002: ...Index 22 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA INDEX ...
Page 1006: ......