MC9S12XA256CAL Freescale Semiconductor, MC9S12XA256CAL Datasheet - Page 610

• Manufacturer Part Number: MC9S12XA256CAL
• Description: IC MCU 256K FLASH 112-LQFP
• Manufacturer: Freescale Semiconductor
• Series: HCS12r

Specifications of MC9S12XA256CAL

• Core Processor: HCS12X
• Core Size: 16-Bit
• Speed: 80MHz
• Connectivity: EBI/EMI, I²C, IrDA, LIN, SCI, SPI
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 91
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 2.35 V ~ 5.5 V
• Data Converters: A/D 16x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 112-LQFP
• No. Of I/o's: 91
• Eeprom Memory Size: 4KB
• Ram Memory Size: 16KB
• Cpu Speed: 80MHz
• No. Of Timers: 1
• No. Of Pwm Channels: 8
• Digital Ic Case Style: LQFP
• Rohs Compliant: Yes
• Processor Series: S12XA
• Core: HCS12
• Data Bus Width: 16 bit
• Data Ram Size: 16 KB
• Interface Type: CAN, I2C, SCI, SPI
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 91
• Number Of Timers: 12
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWHCS12
• Development Tools By Supplier: EVB9S12XDP512E
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 2 (10 bit, 16 Channel)
• Package: 112LQFP
• Family Name: HCS12
• Maximum Speed: 40 MHz
• Operating Supply Voltage: 2.5|5 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Chapter 16 Interrupt (S12XINTV1)
16.5
16.5.1
After system reset, software should:
16.5.2
The interrupt request priority level scheme makes it possible to implement priority based interrupt request
nesting for the I bit maskable interrupt requests handled by the CPU.
I bit maskable interrupt requests cannot be interrupted by other I bit maskable interrupt requests per
default. In order to make an interrupt service routine (ISR) interruptible, the ISR must explicitly clear the
I bit in the CCR (CLI). After clearing the I bit, I bit maskable interrupt requests with higher priority can
interrupt the current ISR.
An ISR of an interruptible I bit maskable interrupt request could basically look like this:
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Initialize the interrupt vector base register if the interrupt vector table is not located at the default
location (0xFF10–0xFFF9).
Initialize the interrupt processing level configuration data registers (INT_CFADDR,
INT_CFDATA0–7) for all interrupt vector requests with the desired priority levels and the request
target (CPU or XGATE module). It might be a good idea to disable unused interrupt requests.
If the XGATE module is used, setup the XGATE interrupt priority register (INT_XGPRIO) and
configure the XGATE module (please refer the XGATE Block Guide for details).
Enable I maskable interrupts by clearing the I bit in the CCR.
Enable the X maskable interrupt by clearing the X bit in the CCR (if required).
I bit maskable interrupt requests can be interrupted by an interrupt request with a higher priority,
so that there can be up to seven nested I bit maskable interrupt requests at a time (refer to
Figure 16-14
Service interrupt, e.g., clear interrupt flags, copy data, etc.
Clear I bit in the CCR by executing the instruction CLI (thus allowing interrupt requests with
higher priority)
Process data
Return from interrupt by executing the instruction RTI
Initialization/Application Information
Initialization
Interrupt Nesting
for an example using up to three nested interrupt requests).
MC9S12XDP512 Data Sheet, Rev. 2.21
Freescale Semiconductor