Freescale Semiconductor MPC8260 4.3 Programming Model

System Interface Unit (SIU)
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 4-17
Requests can be masked independently in the interrupt mask register (SIMR). Notice that the global SIMR
is cleared on system reset so pins left floating do not cause false interrupts.
4.3 Programming Model
The SIU registers are grouped into the following three categories:
• Interrupt controller registers. These registers control configuration, prioritization, and masking of
interrupts. They also include registers for determining the interrupt sources. These registers are
described in Section 4.3.1, “Interrupt Controller Registers.”
• System configuration and protection registers. These include registers for configuring the SIU,
defining the base address for the internal memory map, configuring the watchdog timer, specifying
bus characteristics, as well as general functionality of the 60x, and local buses such as arbitration,
error status, and control. These registers are described in Section 4.3.2, “System Configuration and
Protection Registers.”
• Periodic interrupt registers. These include registers for configuring and providing status for
periodic interrupts. See Section 4.3.3, “Periodic Interrupt Registers.”
4.3.1 Interrupt Controller Registers
There are seven interrupt controller registers, described in the following sections:
•Section 4.3.1.1, “SIU Interrupt Configuration Register (SICR)”
•Section 4.3.1.2, “SIU Interrupt Priority Register (SIPRR)”
•Section 4.3.1.3, “CPM Interrupt Priority Registers (SCPRR_H and SCPRR_L)”
•Section 4.3.1.4, “SIU Interrupt Pending Registers (SIPNR_H and SIPNR_L)”
•Section 4.3.1.5, “SIU Interrupt Mask Registers (SIMR_H and SIMR_L)”
•Section 4.3.1.6, “SIU Interrupt Vector Register (SIVEC)”
•Section 4.3.1.7, “SIU External Interrupt Control Register (SIEXR)”
4.3.1.1 SIU Interrupt Configuration Register (SICR)
The SIU interrupt configuration register (SICR), shown in Figure4-10, defines the highest priority
interrupt and whether interrupts are grouped or spread in the priority table, Tab le 4-2 .
01 2 78 131415
Field — HP — GSIU SPS
Reset 0000_0000_0000_0000
R/W R/W
Addr 0x0x10C00
Figure 4-10. SIU Interrupt Configuration Register (SICR)