This article describes device specifics of the ST STR91x series devices.
These device are ARM966E-S based. We recommend to use adaptive clocking for these devices.
The devices have 3 TAP controllers built-in. When starting J-Link.exe , it reports 3 JTAG devices. A special tool, J-Link STR9 Commander ( JLinkSTR91x.exe ) is available to directly access the flash controller of the device. This tool can be used to erase the flash of the controller even if a program is in flash which causes the ARM core to stall. For more information about the J-Link STR9 Commander, please refer to the J-Link User Manual (UM08001). When starting the STR91x commander, a command sequence will be performed which brings MCU into Turbo Mode. "While enabling the Turbo Mode, a dedicated test mode signal is set and controls the GPIOs in output. The IOs are maintained in this state until a next JTAG instruction is sent." (ST Microelectronics) Enabling Turbo Mode is necessary to guarantee proper function of all commands in the STR91x Commander.
Switching the boot bank
The bootbank of the STR91x devices can be switched by using the J-Link STR9 Commander which is part of the J-Link software and documentation package. For more information about the J-Link STR9 Commander, please refer to the J-Link User Manual (UM08001).