mcf51ac256a Freescale Semiconductor, Inc, mcf51ac256a Datasheet - Page 308

• Manufacturer Part Number: mcf51ac256a
• Description: Mcf51ac Flexis
• Manufacturer: Freescale Semiconductor, Inc

Interrupt Controller (CF1_INTC)
13.6.2
Section 13.3.2, “INTC Programmable Level 6, Priority {7,6} Registers (INTC_PL6P{7,6}),”
control registers that provide the ability to dynamically alter the request level and priority of two IRQs.
Specifically, these registers provide the ability to reassign two IRQs to be the highest level 6 (maskable)
requests. Consider the following example.
Suppose the system operation desires to remap the receive and transmit interrupt requests of a serial
communication device (SCI1) as the highest two maskable interrupts. The default assignments for the
SCI1 transmit and receive interrupts are:
To remap these two requests, the INTC_PL6P{7,6} registers are programmed with the desired interrupt
source number:
The reset state of the INTC_PL6P{7,6} registers disables any request remapping.
Another example is to remap the interrupt requests of two ACMPx as the highest two maskable interrupts.
The default assignments for the ACMP1 and ACMP2 e interrupts are:
To remap these two requests, the INTC_PL6P{7,6} registers are programmed with the desired interrupt
source number:
13-18
2. Execution of MOVE.w #0x2700,SR as the first instruction of an ISR.
3. Static assertion of CPUCR[IME] that forces the processor to load SR[I] with seven automatically
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upon the occurrence of an interrupt exception. Because this method removes the need to execute
multi-cycle instructions of #1 or #2, this approach improves system performance.
sci1_rx = interrupt source 19 = vector 83 = level 3, priority 3
sci1_tx = interrupt source 20 = vector 84 = level 3, priority 2
Setting INTC_PL6P7 to 19(0x13), remaps sci1_rx as level 6, priority 7.
Setting INTC_PL6P6 to 18(0x12), remaps sci1_tx as level 6, priority 6.
ACMP1 = interrupt source 54 = vector 118 = level 2, priority 2
ACMP2 = interrupt source 55 = vector 119 = level 2, priority 1
Setting INTC_PL6P7 to 38(0x26), remaps ACMP1 as level 6, priority 7.
Setting INTC_PL6P6 to 39(0x27), remaps ACMP2 as level 6, priority 6.
Using INTC_PL6P{7,6} Registers
The INTC_PL6P{7,6} registers are programmed with the desired interrupt
source number if its vector number lies in range of 64 to 93. If its vector
number is larger than 109, the INTC_PL6P{7,6} registers are programmed
with the desired interrupt source number minus 16.
MCF51AC256 ColdFire Integrated Microcontroller Reference Manual, Rev. 5
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