TXZ Family
Flash Memory
2018-06-05
82 / 120
Rev. 2.0
Mode Determination
The transition destination is determined by the status of RESET_N pin or the status of BOOT_N pin at deassertion
of Power On Reset (POR).
Table 6.2 Operation mode setting
Operation mode
Pin
RESET_N
BOOT_N
Single chip mode
Dual mode
0
1
1
Single boot mode
(Note)
0
1
0
-
0
Note: All products do not support the determination of the transition destination by the deassertion of Power On
Reset (POR). For the details, refer to “Product Information” in Reference manual.
Memory Map in Each Mode
Refer to “Figure 1.1 The example of a memory map”.
How to Reprogramming the Flash
The user boot mode reprograms the flash memory using the program in the on-chip RAM on the user’s set. This
mode is used when the data transfer bus for the flash memory program code on the user application is different from
the UART. It operates in single chip mode; therefore, normal mode, in which user application is activated in single
chip mode, needs to switch to user boot mode for programming flash memory. For that reason, the user is required
to add a mode judgment routine to the reset service routine in the user application program.
This mode switch condition is required to be constructed according to the user system set condition. A flash
memory programming routine, which is uniquely made by the user, needs to be installed in the new application.
This routine is used for programming after being switched to the user boot mode. It is recommended that
program/erase protection is set to the necessary block to avoid accidental modification in single chip mode (normal
operation mode) after reprogramming is completed. Make sure not to generate any exception in user boot mode.
The following section explains two procedures where the reprogramming routine stored in Flash memory (1-A) and
the reprogramming routine is transferred from the external device (1-B). For details of the programming/erasing the
flash memory, refer to “4 Details of Flash Memory”.