NXP Semiconductors MPC5566 - Edge-Detect Events

System Integration Unit (SIU)
MPC5566 Microcontroller Reference Manual, Rev. 2
6-8 Freescale Semiconductor
• IRQ flag bit is set in the external interrupt status register (SIU_EISR)
• Bit is set in the overrun request enable and overrun status registers (SIU_ORER, SIU_OSR)
• Rising- or falling-edge event triggers an interrupt request
The SIU outputs one overrun IRQ bit that is the logical OR of all of the IRQ overrun bits.
Refer to the following sections for more information:
Section 6.3.1.4, “External Interrupt Status Register (SIU_EISR)”
Section 6.3.1.7, “Overrun Status Register (SIU_OSR)”
Section 6.3.1.8, “Overrun Request Enable Register (SIU_ORER)”
6.2.1.6.4 Edge-Detect Events
An IRQ asserts when an:
• Edge-detect event is enabled
• Edge-detect event occurs
To assert an IRQ when an edge-detect event occurs:
1. Set the enable bit in the IRQ rising- and falling-edge event enable registers
(SIU_IREER, SIU_IFEER)
2. Clear the enable bits for the DMA/Interrupt request enable register (SIU_DIRER)
The IRQ bit is set in the external IRQ status register (SIU_EISR) when an edge-detect event occurs for
that IRQ.
Refer to the following sections for more information:
Section 6.3.1.4, “External Interrupt Status Register (SIU_EISR)”
Section 6.3.1.9, “IRQ Rising-Edge Event Enable Register (SIU_IREER)”
Section 6.3.1.10, “IRQ Falling-Edge Event Enable Register (SIU_IFEER)”
6.3 Memory Map and Register Definition
Table 6-5 is the address map for the SIU registers. All register addresses shown are an offset of the SIU
base address.
Table 6-5. SIU Register Address Map
Address Name Description Bits
Base = 0xC3F9_0000 Reserved
Base + 0x0004 SIU_MIDR MCU ID register 32
Base + 0x0008 Reserved
Base + 0x000C SIU_RSR Reset status register 32
Base + 0x0010 SIU_SRCR System reset control register 32
Base + 0x0014 SIU_EISR SIU external interrupt status register 32