SH7058 Datasheet, PDF (921/1130 Pages) Renesas Technology Corp – Renesas SuperHTM RISC engine

The area that can be executed in the steps of the user procedure program (on-chip RAM, user
MAT, and external space) is shown in section 23.10.3, Storable Area for Procedure Program
and Programming Data.
(3) User MAT Erasing in User Boot Mode
For erasing the user MAT in user boot mode, additional processings made by setting FMATS
are required: switching from user-boot-MAT selection state to user-MAT selection state, and
switching back to user-boot-MAT selection state after erasing completes.
Figure 23.15 shows the procedure for erasing the user MAT in user boot mode.
Start erasing
procedure program
Select on-chip program
to be downloaded and
set download destination
by FTDAR
Set FKEY to H'A5
1
Set FMATS to value other
MAT
than H'AA to select user MAT _switchover
After clearing VBR,
set SCO to 1 and
execute download
Clear FKEY to 0
DPFR=0 ?
No
Yes _{Download error processing}
Set the FPEFEQ and
FUBRA parameters
Initialization
JSR FTDAR setting+32
FPFR=0 ?
No
Yes _{Initialization error processing}
1
Set FKEY to H'5A
Set FEBS parameter
Programming
JSR FTDAR setting+16
FPFR=0 ?
No
Yes Clear FKEY and erasing
error processing*
Required
No _{block erasing is}
completed?
Yes
Clear FKEY to 0
Set FMATS to H'AA to
MAT
select user boot MAT switchover
User-boot-MAT
selection state
End erasing
procedure program
Note: * The MAT must be switched by FMATS to perform the
erasing error processing in the user boot MAT.
Figure 22.15 Procedure for Erasing User MAT in User Boot Mode
The difference between the erasing procedures in user program mode and user boot mode depends
on whether the MAT is switched or not as shown in figure 23.15.
MAT switching is enabled by writing a specific value to FMATS. However note that while the
MATs are being switched, the LSI is in an unstable state, e.g. access to a MAT is not allowed until
MAT switching is completed finished, and if an interrupt occurs, from which MAT the interrupt
Rev. 3.0, 09/04, page 880 of 1086