STR910FAZ32H6T STMICROELECTRONICS [STMicroelectronics], STR910FAZ32H6T Datasheet - Page 16

• Manufacturer Part Number: STR910FAZ32H6T
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Functional overview
3.7.1
3.7.2
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Both Flash memories are blank when devices are shipped from ST. The CPU can boot only
from Flash memory (configurable selection of which Flash bank).
Flash memories are programmed half-word (16 bits) at a time, but are erased by sector or
by full array.
Primary Flash memory
Using the STR91xFA device configuration software tool and 3rd party Integrated Developer
Environments, it is possible to specify that the primary Flash memory is the default memory
from which the CPU boots at reset, or otherwise specify that the secondary Flash memory is
the default boot memory. This choice of boot memory is non-volatile and stored in a location
that can be programmed and changed only by JTAG In-System Programming. See
Section 6: Memory
The primary Flash memory has equal length 64K byte sectors. See
sectors per device type.
Table 4.
Secondary Flash memory
The smaller of the two Flash memories can be used to implement a bootloader, capable of
storing code to perform robust In-Application Programming (IAP) of the primary Flash
memory. The CPU executes code from the secondary Flash, while updating code in the
primary Flash memory. New code for the primary Flash memory can be downloaded over
any of the interfaces on the STR91xFA (USB, Ethernet, CAN, UART, etc.)
Additionally, the Secondary Flash memory may also be used to store small data sets by
emulating EEPROM through firmware, eliminating the need for external EEPROM
memories. This raises the data security level because passcodes and other sensitive
information can be securely locked inside the STR91xFA device.
The secondary Flash memory is sectored as shown in
Both the primary Flash memory and the secondary Flash memory can be programmed with
code and/or data using the JTAG In-System Programming (ISP) channel, totally
independent of the CPU. This is excellent for iterative code development and for
manufacturing.
Table 5.
Size of Secondary Flash
Size of Primary Flash
Size of each sector
Size of each sector
Number of sectors
Number of sectors
Sectoring of primary Flash memory
Sectoring of secondary Flash memory
mapping, for more detail.
STR91xFAx32 STR91xFAx42 STR91xFAx44
256 KBytes
4
Table 5
32 KBytes
64 Kbytes
8 Kbytes
according to device type.
4
Table 4
512 KBytes
for number of
8