参数资料
型号: STR912FW42X6
厂商: STMICROELECTRONICS
元件分类: 微控制器/微处理器
英文描述: 32-BIT, FLASH, 96 MHz, RISC MICROCONTROLLER, PQFP128
封装: 14 X 14 MM, PLASTIC, LQFP-128
文件页数: 38/73页
文件大小: 1538K
代理商: STR912FW42X6
Obsolete
Product(s)
- Obsolete
Product(s)
STR91xF
Memory mapping
43/73
When other AHB bus masters (such as a DMA controller) write to SRAM, their access is never
buffered. Only the CPU can make use of buffered AHB writes.
5.4
Two independent Flash memories
The STR91xF has two independent Flash memories, the larger primary Flash and the small
secondary Flash. It is possible for the CPU to erase/write to one of these Flash memories while
simultaneously reading from the other.
One or the other of these two Flash memories may reside at the “boot” address position of
0x0000.0000 at power-up or at reset as shown in Figure 9. The default configuration is that the
first sector of primary Flash memory is enabled and residing at the boot position, and the
secondary Flash memory is disabled. This default condition may be optionally changed as
described below.
5.4.1
Default configuration
When the primary Flash resides at boot position, typical CPU initialization firmware would set
the start address and size of the main Flash memory, and go on to enable the secondary Flash,
define it’s start address and size. Most commonly, firmware would place the secondary Flash
start address at the location just after the end of the primary Flash memory. In this case, the
primary Flash is used for code storage, and the smaller secondary flash can be used for data
storage (EEPROM emulation).
5.4.2
Optional configuration
Using the STR91xF device configuration software tool, or IDE from 3rd party, one can specify
that the smaller secondary Flash memory is at the boot location at reset and the primary Flash
is disabled. The selection of which Flash memory is at the boot location is programmed in a
non-volatile Flash-based configuration bit during JTAG ISP. The boot selection choice will
remain as the default until the bit is erased and re-written by the JTAG interface. The CPU
cannot change this choice for boot Flash, only the JTAG interface has access.
In this case where the secondary Flash defaults to the boot location upon reset, CPU firmware
would typically initialize the Flash memories the following way. The secondary Flash start
address and size is specified, then the primary Flash is enabled and its start address and size
is specified. The primary Flash start address would typically be located just after the final
address location of the secondary Flash. This configuration is particularly well-suited for In-
Application-Programming (IAP). The CPU would boot from the secondary Flash memory,
initialize the system, then check the contents of the primary Flash memory (by checksum or
other means). If the contents of primary Flash is OK, then CPU execution continues from either
Flash memory. If the main Flash contents are incorrect, the CPU, while executing code from the
secondary Flash, can download new data from any STR91xF communication channel and
program into primary Flash memory. Application code then starts after the new contents of
primary Flash are verified.
相关PDF资料
PDF描述
STW0Q14A SINGLE COLOR LED, WHITE
STW0Q2PA SINGLE COLOR LED, WHITE
STW1145LTM SINGLE COLOR LED, WHITE, 1.9 mm
STW8T16A SINGLE COLOR LED, WHITE
STWD100NWWY3F PROGRAMMABLE TIMER, PDSO5
相关代理商/技术参数
参数描述
STR912FW42X6 制造商:STMicroelectronics 功能描述:256K Flash 96K sram Ethernet USB CAN
STR912FW42X6T 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:ARM966E-S TM 16/32-Bit Flash MCU with Ethernet, USB, CAN, AC motor control, 4 timers, ADC, RTC, DMA
STR912FW44X6 功能描述:ARM微控制器 - MCU TQFP 128 14x14x1.4 1 RoHS:否 制造商:STMicroelectronics 核心:ARM Cortex M4F 处理器系列:STM32F373xx 数据总线宽度:32 bit 最大时钟频率:72 MHz 程序存储器大小:256 KB 数据 RAM 大小:32 KB 片上 ADC:Yes 工作电源电压:1.65 V to 3.6 V, 2 V to 3.6 V, 2.2 V to 3.6 V 工作温度范围:- 40 C to + 85 C 封装 / 箱体:LQFP-48 安装风格:SMD/SMT
STR912FW44X6 制造商:STMicroelectronics 功能描述:512K Flash 96K sram Ethernet USB CAN
STR912FW44X6T 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:ARM966E-S TM 16/32-Bit Flash MCU with Ethernet, USB, CAN, AC motor control, 4 timers, ADC, RTC, DMA