Datasheet

Table Of Contents
Section 19 Flash Memory (F-ZTAT Version)
REJ09B0140-0900 Rev. 9.00 Page 647 of 846
Sep 16, 2010
H8S/2215 Group
2. When the boot program is activated, enumeration with respect to the host is carried out.
Enumeration information is shown in table 19.6. When enumeration is completed, transmit a
single H'55 byte from the host. If reception has not been performed normally, restart boot
mode by means of a reset.
3. Set the frequency for transmission from the host as a numeric value in units of MHz × 100 (ex:
16.00 MHZ H'0640).
4. In boot mode, the 4-kbyte on-chip RAM area H'FFE000 to H'FFEFBF is used by the boot
program. The programming control program transmitted from the host can be stored in the 8-
kbyte area H'FFC000 to H'FFDFFF. The boot program area cannot be used until program
execution switches to the programming control program. Also note that the boot program
remains in RAM even after control passes to the programming control program.
5. When a branch is made to the programming control program, the USB remains connected and
can be used immediately for transmission/reception of write data or verify data between the
programming control program and the host. The contents of CPU general registers are
undefined after a branch to the programming control program. Note, in particular, that since the
stack pointer is used implicitly in subroutine calls and the like, it should be initialized at the
start of the programming control program.
6. Boot mode is exited by means of a reset. Drive the reset pin low, wait for the elapse of at least
20 states, then set the FWE pin and mode pins to release
*
the reset. Boot mode is also exited in
the event of a WDT overflow reset.
7. Do not change the input level of the mode pins while in boot mode. If the input level of a mode
pin is changed (from low to high) during a reset, the states of ports with a dual function as
address outputs, and bus control output signals (AS, RD, WR), will change due to switching of
the operating mode. Either make pin settings so that these pins do not become output signal
pins during a reset, or take precautions to prevent collisions with external signals.
8. Interrupts cannot be used during flash memory programming or erasing.
Note: * FWE pin and mode pin input must satisfy the mode programming setup time (t
MDS
=
200 ns) when a reset is released.