STR912FW42X6 STMicroelectronics, STR912FW42X6 Datasheet - Page 7

• Manufacturer Part Number: STR912FW42X6
• Description: MCU 256K FLASH 96K SRAM USB CAN
• Manufacturer: STMicroelectronics
• Series: STR9r

Specifications of STR912FW42X6

• 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: 256KB (256K 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
• For Use With: 497-8267 - BOARD EVAL BASED ON STR9MCBSTR9UME - BOARD EVAL MCBSTR9 + ULINK-MEMCBSTR9U - BOARD EVAL MCBSTR9 + ULINK2497-5859 - EVAL BRD FULL USB DONGLE STR912MCBSTR9 - BOARD EVAL STM STR9 SERIES
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Other names: 497-5062; 497-5062-2; 497-5062-2; STR912FW42X6T

STR91xF
2
2.1
2.2
2.3
2.4
2.4.1
Functional overview
System-in-a-Package (SiP)
The STR91xF is a SiP device, comprised of two stacked die. One die is the ARM966E-S CPU
with peripheral interfaces and analog functions, and the other die is the burst Flash. The two die
are connected to each other by a custom high-speed 32-bit burst memory interface and a serial
JTAG test/programming interface.
Package choice
STR91xF devices are available in 128-pin (14 x 14 mm) and 80-pin (12 x 12 mm) LQFP
packages. Refer to the
peripherals for each of the package choices.
ARM966E-S CPU core
The ARM966E-S core inherently has separate instruction and data memory interfaces (Harvard
architecture), allowing the CPU to simultaneously fetch an instruction, and read or write a data
item through two Tightly-Coupled Memory (TCM) interfaces as shown in
streamlined CPU Load and Store operations and a significant reduction in cycle count per
instruction. In addition to this, a 5-stage pipeline is used to increase the amount of operational
parallelism, giving the most performance out of each clock cycle.
Ten DSP-enhanced instruction extensions are supported by this core, including single-cycle
execution of 32x16 Multiply-Accumulate, saturating addition/subtraction, and count leading-
zeros.
The ARM966E-S core is binary compatible with 32-bit ARM7 code and 16-bit Thumb
Burst Flash memory interface
A Burst Flash memory interface
(I-TCM) path of the ARM966E-S core. Also in this path is a 4-instruction Pre-Fetch Queue
(PFQ) and a 4-entry Branch Cache (BC), enabling the ARM966E-S core to perform up to 96
MIPS while executing code directly from Flash memory. This architecture provides high
performance levels without a costly instruction SRAM, instruction cache, or external SDRAM.
Eliminating the instruction cache also means interrupt latency is reduced and code execution
becomes more deterministic.
Pre-Fetch Queue (PFQ)
As the CPU core accesses sequential instructions through the I-TCM, the PFQ always looks
ahead and will pre-fetch instructions, taking advantage any idle bus cycles due to variable
length instructions. The PFQ will fetch 32-bits at a time from the Burst Flash memory at a rate
of up to 96 MHz.
Table 1 on page 6
(Figure
1) has been integrated into the Instruction TCM
and to
Table 31 on page 70
for a list of available
Figure
Functional overview
1. The result is
®
code.
7/73