UCD3138128APFC datasheet(23/83 Pages) TI1

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UCD3138128A

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SLUSC99 – JULY 2016

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9.3 Feature Description

9.3.1 System Module

The System Module contains the interface logic and configuration registers to control and configure all the

memory, peripherals and interrupt mechanisms. The blocks inside the system module are the address decoder,

memory management controller, system management unit, central interrupt unit, and clock control unit.

9.3.1.1 Address Decoder (DEC)

The Address Decoder generates the memory selects for the FLASH, ROM and RAM arrays. The memory map

addresses are selectable through configurable register settings. These memory selects can be configured from 1

kB to 16 MB. Power on reset uses the default addresses in the memory map for ROM execution, which is then

configured by the ROM code to the application setup. During access to the DEC registers, a wait state is

asserted to the CPU. DEC registers are only writable in the ARM privilege mode for user mode protection.

9.3.1.2 Memory Management Controller (MMC)

The MMC manages the interface to the peripherals by controlling the interface bus for extending the read and

write accesses to each peripheral. The unit generates eight peripheral select lines with 1 kB of address space

decoding.

9.3.1.3 System Management (SYS)

The SYS unit contains the software access protection by configuring user privilege levels to memory or

peripherals modules. It contains the ability to generate fault or reset conditions on decoding of illegal address or

access conditions. A clock control setup for the processor clock (MCLK) speed, is also available.

9.3.1.4 Central Interrupt Module (CIM)

The CIM accepts 32 interrupt requests for meeting firmware timing requirements. The ARM processor supports

two interrupt levels: FIQ and IRQ. FIQ is the highest priority interrupt. The CIM provides hardware expansion of

interrupts by use of FIQ/IRQ vector registers for providing the offset index in a vector table. This numerical index

value indicates the highest precedence channel with a pending interrupt and is used to locate the interrupt vector

address from the interrupt vector table. Interrupt channel 0 has the lowest precedence and interrupt channel 31

has the highest precedence. To remove the interrupt request, the firmware should clear the request as the first

action in the interrupt service routine. The request channels are maskable, allowing individual channels to be

selectively disabled or enabled.

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