YR0K42378FC000BA Renesas Electronics America, YR0K42378FC000BA Datasheet - Page 991

• Manufacturer Part Number: YR0K42378FC000BA
• Description: KIT EVAL FOR H8S/2378
• Manufacturer: Renesas Electronics America
• Series: H8®r
• Type: MCUr

Specifications of YR0K42378FC000BA

• Contents: Board
• For Use With/related Products: H8S/2378
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

21.6
It is possible to alternate between the user MAT and user boot MAT. However, the following
procedure is required because these MATs are allocated to address 0.
(Switching to the user boot MAT disables programming and erasing. Programming of the user
boot MAT should take place in boot mode or PROM mode.)
1. MAT switching by FMATS should always be executed from the on-chip RAM.
2. To ensure that the MAT that has been switched to is accessible, execute four NOP instructions
3. If an interrupt has occurred during switching, there is no guarantee of which memory MAT is
4. After the MATs have been switched, take care because the interrupt vector table will also have
5. Memory sizes of the user MAT and user boot MAT are different. When accessing the user
in the on-chip RAM immediately after writing to FMATS of the on-chip RAM (this prevents
access to the flash memory during MAT switching).
being accessed. Always mask the maskable interrupts before switching between MATs. In
addition, configure the system so that NMI interrupts do not occur during MAT switching.
been switched. If interrupt processing is to be the same before and after MAT switching,
transfer the interrupt-processing routines to the on-chip RAM, and use the settings of FVACR
to place the interrupt-vector table in the on-chip RAM .
boot MAT, do not access addresses above the top of its 8-kbyte memory space. If access goes
beyond the 8-kbyte space, the values read are undefined.
Switching between User MAT and User Boot MAT
Figure 21.16 Switching between the User MAT and User Boot MAT
< User MAT >
Procedure for switching to the user boot MAT
(1) Mask interrupts
(2) Write H'AA to FMATS.
(3) Execute four NOP instructions before
Procedure for switching to the user MAT
(1) Mask interrupts
(2) Write a value other than H'AA to FMATS.
(3) Execute four NOP instructions before accessing
accessing the user boot MAT.
the user MAT.
< On-chip RAM >
switching to the
user boot MAT
Procedure for
Procedure for
the user MAT
switching to
Section 21 Flash Memory (0.18-μm F-ZTAT Version)
Rev.7.00 Mar. 18, 2009 page 923 of 1136
< User boot MAT >
REJ09B0109-0700