STR912FAW46X6T STMicroelectronics, STR912FAW46X6T Datasheet - Page 18
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STR912FAW46X6T
Manufacturer Part Number
STR912FAW46X6T
Description
MCU 16/32BIT FLASH 128-TQFP
Manufacturer
STMicroelectronics
Series
STR9r
Datasheet
1.STEVAL-IFW001V1.pdf
(102 pages)
Specifications of STR912FAW46X6T
Core Processor
ARM9
Core Size
32-Bit
Speed
96MHz
Connectivity
CAN, EBI/EMI, Ethernet, I²C, IrDA, Microwire, SPI, SSI, SSP, UART/USART, USB
Peripherals
Brown-out Detect/Reset, DMA, Motor Control PWM, POR, PWM, WDT
Number Of I /o
80
Program Memory Size
1MB (1M x 8)
Program Memory Type
FLASH
Ram Size
96K x 8
Voltage - Supply (vcc/vdd)
1.65 V ~ 2 V
Data Converters
A/D 8x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
128-LQFP
Processor Series
STR912x
Core
ARM966E-S
3rd Party Development Tools
EWARM, EWARM-BL, MCBSTR9, MCBSTR9U, MCBSTR9UME, KSDK-STR912-PLUS, MDK-ARM, RL-ARM, ULINK2
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Eeprom Size
-
Lead Free Status / Rohs Status
Details
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
STR912FAW46X6T
Manufacturer:
STMicroelectronics
Quantity:
10 000
Functional overview
3.9
3.9.1
3.9.2
Note:
3.9.3
18/102
Vectored interrupt controller (VIC)
Interrupt management in the STR91xFA is implemented from daisy-chaining two standard
ARM VIC units. This combined VIC has 32 prioritized interrupt request channels and
generates two interrupt output signals to the CPU. The output signals are FIQ and IRQ, with
FIQ having higher priority.
FIQ handling
FIQ (Fast Interrupt reQuest) is the only non-vectored interrupt and the CPU can execute an
Interrupt Service Routine (ISR) directly without having to determine/prioritize the interrupt
source, minimizing ISR latency. Typically only one interrupt source is assigned to FIQ. An
FIQ interrupt has its own set of banked registers to minimize the time to make a context
switch. Any of the 32 interrupt request input signals coming into the VIC can be assigned to
FIQ.
IRQ handling
IRQ is a vectored interrupt and is the logical OR of all 32 interrupt request signals coming
into the 32 IRQ channels. Priority of individual vectored interrupt requests is determined by
hardware (IRQ channel Intr 0 is highest priority, IRQ channel Intr 31 is lowest).
However, inside the same VIC (primary or secondary VIC), CPU firmware may re-assign
individual interrupt sources to individual hardware IRQ channels, meaning that firmware can
effectively change interrupt priority levels as needed within the same VIC (from priority 0 to
priority 16).
VIC0 (primary VIC) interrupts always have higher priority than VIC1 (secondary VIC)
interrupts
When the IRQ signal is activated by an interrupt request, VIC hardware will resolve the IRQ
interrupt priority, then the ISR reads the VIC to determine both the interrupt source and the
vector address to jump to the service code.
The STR91xFA has a feature to reduce ISR response time for IRQ interrupts. Typically, it
requires two memory accesses to read the interrupt vector address from the VIC, but the
STR91xFA reduces this to a single access by adding a 16th entry in the instruction branch
cache, dedicated for interrupts. This 16th cache entry always holds the instruction that reads
the interrupt vector address from the VIC, eliminating one of the memory accesses typically
required in traditional ARM implementations.
Interrupt sources
The 32 interrupt request signals coming into the VIC on 32 IRQ channels are from various
sources; 5 from a wake-up unit and the remaining 27 come from internal sources on the
STR91xFA such as on-chip peripherals, see
interrupt on any IRQ channel.
One of the 5 interrupt requests generated by the wake-up unit (IRQ25 in
from the logical OR of all 32 inputs to the wake-up unit. Any of these 32 inputs may be used
to wake up the CPU and cause an interrupt. These 32 inputs consist of 30 external
interrupts on selected and enabled GPIO pins, plus the RTC interrupt, and the USB Resume
interrupt.
Doc ID 13495 Rev 6
Table
6. Optionally, firmware may force an
Table
STR91xFAxxx
6) is derived