Freescale Semiconductor 56F8122 - Manual (Page 52)

56F8322 Techncial Data, Rev. 10.0
52 Freescale Semiconductor
Preliminary
4.8 Factory-Programmed Memory
The Boot Flash memory block is programmed during manufacturing with a default Serial Bootloader
program. The Serial Bootloader application can be used to load a user application into the Program and
Data Flash (not available on the 56F8122) memories of the device. The 56F83xx SCI/CAN Bootloader
User Manual provides detailed information on this firmware. An application note, Production Flash
Programming, details how the Serial Bootloader program can be used to perform production Flash
programming of the on-board Flash memories as well as other optional methods.
Like all the Flash memory blocks, the Boot Flash can be erased and programmed by the user. The Serial
Bootloader application is programmed as an aid to the end user, but is not required to be used or maintained
in the Boot Flash memory.
Part 5 Interrupt Controller (ITCN)
5.1 Introduction
The Interrupt Controller (ITCN) module is used to arbitrate between various interrupt requests (IRQs), to
signal to the 56800E core when an interrupt of sufficient priority exists, and to what address to jump in
order to service this interrupt.
5.2 Features
The ITCN module design includes these distinctive features:
• Programmable priority levels for each IRQ
• Two programmable Fast Interrupts
• Notification to SIM module to restart clocks out of Wait and Stop modes
• Drives initial address on the address bus after reset
For further information, see Table 4-3 , Interrupt Vector Table Contents.
5.3 Functional Description
The Interrupt Controller is a slave on the IPBus. It contains registers allowing each of the 82 interrupt
sources to be set to one of four priority levels, excluding certain interrupts of fixed priority. Next, all of
the interrupt requests of a given level are priority encoded to determine the lowest numerical value of the
active interrupt requests for that level. Within a given priority level, 0 is the highest priority, while number
81 is the lowest.
5.3.1 Normal Interrupt Handling
Once the ITCN has determined that an interrupt is to be serviced and which interrupt has the highest
priority, an interrupt vector address is generated. Normal interrupt handling concatenates the VBA and the
vector number to determine the vector address. In this way, an offset is generated into the vector table for
each interrupt.