h8s-2172 Renesas Electronics Corporation., h8s-2172 Datasheet - Page 447

• Manufacturer Part Number: h8s-2172
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family H8s-2100 Series
• Manufacturer: Renesas Electronics Corporation.

14.4.3
User Boot Mode
This LSI has user boot mode which is initiated with different mode pin settings than those in boot
mode or user program mode. User boot mode is a user-arbitrary boot mode, unlike boot mode that
uses the on-chip SCI.
Only the user MAT can be programmed/erased in user boot mode. Programming/erasing of the
user boot MAT is only enabled in boot mode or programmer mode.
User Boot Mode Initiation: For the mode pin settings to start up user boot mode, see table 14.6.
When the reset start is executed in user boot mode, the built-in check routine runs. The user MAT
and user boot MAT states are checked by this check routine.
While the check routine is running, NMI and all other interrupts cannot be accepted.
Next, processing starts from the execution start address of the reset vector in the user boot MAT.
At this point, H'AA is set to FMATS because the execution MAT is the user boot MAT.
User MAT Programming in User Boot Mode: For programming the user MAT in user boot
mode, additional processing made by setting FMATS is required: switching from user-boot-MAT
selection state to user-MAT selection state, and switching back to user-boot-MAT selection state
after programming completes.
Figure 14.14 shows the procedure for programming the user MAT in user boot mode.
Rev. 2.00, 03/04, page 415 of 534