Cautions On Clearing The Software Standby Mode Of F-Ztat Version - Hitachi H8/3062 Hardware Manual

21.4.6

Cautions on Clearing the software Standby Mode of F-ZTAT Version

(1) Operation phenomena
When using operating mode 5, 6, or 7 * (on-chip flash memory enabled), the first read of on-
chip flash memory after exiting software standby mode may not be carried out correctly.
Software standby mode is exited by means of an external interrupt (via the NMI, IRQ
or IRQ pin), the RES pin, or the STBY pin. In the case of an external interrupt via the NMI,
2
IRQ , IRQ , or IRQ
0 1
vector corresponding to the respective exception handling interrupt source. This vector may
not be read correctly, resulting in program runaway.
Note: * Mode 5: expanded 16-Mbyte mode with on-chip ROM enabled
Mode 6: single-chip normal mode
Mode 7: single-chip advanced mode
(2) Exemplary procedures to avoid program runaway
This operation phenomenon can be avoided by writing or amending program code in
accordance with the following procedures.
(a) When using mode 5 or mode 7, assign addresses in the 64-kbyte space from H'00000 to
H'0FFFF as the vector addresses for the external interrupts that clear software standby
mode.
(b) When using mode 6, change the mode to mode 7 in the program, and use change (a) above.
Note that it is necessary to change vector address assignments and to extend addresses as
follows.
• Addresses H'DFFF and below (on-chip ROM area): H'xxxx → H'0xxxx
• Addresses H'E000 to H'E0FF (internal I/O registers-1): H'yyyy → H'Eyyyy
• Addresses H'EF20 and above (on-chip RAM area and internal I/O registers-2): H'zzzz
→ H'Fzzzz
(Where x, y and z are any hexadecimal numbers)
(3) Comparison of products in H8/3062 Series
H8/3062F-ZTAT H8/3062F-ZTAT R-Mask Version
Restriction (2) Prior to week
applies. code "9k1"
Take measures Restriction (2)
to prevent applies.
program
Take measures
runaway.
to prevent
program
runaway.
646
pin, the first read after exiting software standby mode is a read of the
2
Week code "9k1"
onward
Restriction (2)
does not apply.
H8/3062F-ZTAT H8/3064F-ZTAT
B-Mask Version B-Mask Version
Restriction (2) Restriction (2)
does not apply. does not apply.
, IRQ
,
0 1
On-Chip Mask
ROM B-Mask
Versions
Restriction (2)
does not apply.