AT91SAM7A3-AU Atmel, AT91SAM7A3-AU Datasheet - Page 132

• Manufacturer Part Number: AT91SAM7A3-AU
• Description: IC ARM7 MCU FLASH 256K 100LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7A3-AU

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 60MHz
• Connectivity: CAN, I²C, MMC, SPI, SSC, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 62
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-LQFP
• Controller Family/series: AT91SAM7xx
• No. Of I/o's: 62
• Ram Memory Size: 32KB
• Cpu Speed: 60MHz
• No. Of Timers: 3
• Rohs Compliant: Yes
• Package: 100LQFP
• Device Core: ARM7TDMI
• Family Name: 91S
• Maximum Speed: 60 MHz
• Operating Supply Voltage: 3.3 V
• Data Bus Width: 32 Bit
• Number Of Programmable I/os: 62
• Interface Type: CAN/SPI/I2S/TWI/USART/USB
• On-chip Adc: 2(8-chx10-bit)
• Number Of Timers: 3
• Processor Series: AT91SAMx
• Core: ARM7TDMI
• Data Ram Size: 32 KB
• Maximum Clock Frequency: 60 MHz
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JTRACE-ARM-2M, MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: AT91SAM-ICE, AT91-ISP, AT91SAM7A3-EK
• Minimum Operating Temperature: - 40 C
• Cpu Family: 91S
• Device Core Size: 32b
• Frequency (max): 60MHz
• Total Internal Ram Size: 32KB
• # I/os (max): 62
• Number Of Timers - General Purpose: 3
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (max): 3.6V
• Operating Supply Voltage (min): 3V
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 100
• Package Type: LQFP
• For Use With: AT91SAM-ICE - EMULATOR FOR AT91 ARM7/ARM9AT91SAM7A3-EK - KIT EVAL FOR AT91SAM7A3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

22.7.3
22.7.3.1
22.7.3.2
22.7.3.3
132
AT91SAM7A3 Preliminary
Normal Interrupt
Priority Controller
Interrupt Nesting
Interrupt Vectoring
An 8-level priority controller drives the nIRQ line of the processor, depending on the interrupt
conditions occurring on the interrupt sources 1 to 31 (except for those programmed in Fast
Forcing).
Each interrupt source has a programmable priority level of 7 to 0, which is user-definable by
writing the PRIOR field of the corresponding AIC_SMR (Source Mode Register). Level 7 is the
highest priority and level 0 the lowest.
As soon as an interrupt condition occurs, as defined by the SRCTYPE field of the AIC_SMR
(Source Mode Register), the nIRQ line is asserted. As a new interrupt condition might have
happened on other interrupt sources since the nIRQ has been asserted, the priority controller
determines the current interrupt at the time the AIC_IVR (Interrupt Vector Register) is read.
The read of AIC_IVR is the entry point of the interrupt handling which allows the AIC to
consider that the interrupt has been taken into account by the software.
The current priority level is defined as the priority level of the current interrupt.
If several interrupt sources of equal priority are pending and enabled when the AIC_IVR is
read, the interrupt with the lowest interrupt source number is serviced first.
The nIRQ line can be asserted only if an interrupt condition occurs on an interrupt source with
a higher priority. If an interrupt condition happens (or is pending) during the interrupt treatment
in progress, it is delayed until the software indicates to the AIC the end of the current service
by writing the AIC_EOICR (End of Interrupt Command Register). The write of AIC_EOICR is
the exit point of the interrupt handling.
The priority controller utilizes interrupt nesting in order for the high priority interrupt to be han-
dled during the service of lower priority interrupts. This requires the interrupt service routines
of the lower interrupts to re-enable the interrupt at the processor level.
When an interrupt of a higher priority happens during an already occurring interrupt service
routine, the nIRQ line is re-asserted. If the interrupt is enabled at the core level, the current
execution is interrupted and the new interrupt service routine should read the AIC_IVR. At this
time, the current interrupt number and its priority level are pushed into an embedded hardware
stack, so that they are saved and restored when the higher priority interrupt servicing is fin-
ished and the AIC_EOICR is written.
The AIC is equipped with an 8-level wide hardware stack in order to support up to eight inter-
rupt nestings pursuant to having eight priority levels.
The interrupt handler addresses corresponding to each interrupt source can be stored in the
registers AIC_SVR1 to AIC_SVR31 (Source Vector Register 1 to 31). When the processor
reads AIC_IVR (Interrupt Vector Register), the value written into AIC_SVR corresponding to
the current interrupt is returned.
This feature offers a way to branch in one single instruction to the handler corresponding to
the current interrupt, as AIC_IVR is mapped at the absolute address 0xFFFF F100 and thus
accessible from the ARM interrupt vector at address 0x0000 0018 through the following
instruction:
6042E–ATARM–14-Dec-06