I.MX27L_11 Datasheet, PDF (10/152 Pages) Freescale Semiconductor, Inc – Multimedia Applications Processor Multiple clock and power domains

Functional Description and Application Information
2.3.2 AHB-Lite IP Interface Module (AIPI)
The AIPI acts as an interface between the ARM Advanced High-performance Bus Lite. (AHB-Lite) and
lower bandwidth peripherals conforming to the IP bus specification Rev 2.0. There are two AIPI modules
in i.MX27/MX27L processors.
The following list summarizes the key features of the AIPI:
• All peripheral read transactions require a minimum of two system clocks (R-AHB side) and all
write transactions require a minimum of three system clocks (R-AHB side).
• The AIPI supports 8-bit, 16-bit, and 32-bit IP bus peripherals. Byte, half word, and full word reads
and writes are supported.
• The AIPI supports multi-cycle accesses by providing 16-bit to 8-bit peripherals operations and
32-bit to both 16-bit and 8-bit peripherals operations.
• The AIPI supports 31 external IP bus peripherals each with a 4-Kbyte memory map (a slot).
2.3.3 ARM926EJ-S Interrupt Controller (AITC)
The ARM926EJ-S Interrupt Controller (AITC) is a 32-bit peripheral that collects interrupt requests from
up to 64 sources and provides an interface to the ARM926EJ-S core. The AITC includes software
controlled priority levels for normal interrupts.
The AITC performs the following functions:
• Supports up to 64 interrupt sources
• Supports fast and normal interrupts
• Selects normal or fast interrupt request for any interrupt source
• Indicates pending interrupt sources via a register for normal and fast interrupts
• Indicates highest priority interrupt number via register. (Can be used as a table index.)
• Independently can enable or disable any interrupt source
• Provides a mechanism for software to schedule an interrupt
• Supports up to 16 software controlled priority levels for normal interrupts and priority masking
• Can single-bit disable all normal interrupts and all fast interrupts. (Used in enabling of secure
operations.)
2.3.4 ARM926EJ-S Platform
The ARM926EJ-S (ARM926) is a member of the ARM9 family of general-purpose microprocessors
targeted at multi-tasking applications. The ARM926 supports the 32-bit ARM and 16-bit Thumb
instructions sets. The ARM926 includes features for efficient execution of Java byte codes. A JTAG port
is provided to support the ARM Debug Architecture, along with associated signals to support the ETM9
real-time trace module. The ARM926EJ-S is a Harvard cached architecture including an ARM9EJ-S
integer core, a Memory Management Unit (MMU), separate instruction and data AMBA AHB interfaces,
separate instruction and data caches, and separate instruction and data tightly coupled memory (TCM)
interfaces. The ARM926 co-processor, instruction TCM, and data TCM interfaces will be tied off within
the ARM926 Platform and will not be available for external connection.
i.MX27 and i.MX27L Data Sheet, Rev. 1.7
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Freescale Semiconductor