Fujitsu FR60 Hardware Manual page 552

CHAPTER 20 REAL-TIME OS EMBEDDED MB91302A-010 USER'S GUIDE
■ Fetching Mode Data and Reset Vectors after the Device is Released from a Reset
The MB91302A-010 fetches the mode data and reset vector from addresses 000FFFF8
000FFFFC
MB91302A-010, these items of data located at addresses 400FFFF8
R_eit section are fetched when a reset is canceled.
Table 20.7-5 Sequence after a Release from a Reset
Operation
1 Release from a Reset
The entire 32-bit address space becomes
CS0 upon initialization by a reset.
2 The MD2 to MD0 mode pins become "LLH"
which is fixed on the target board after a
reset is canceled.
Fetch a mode vector from external address
000FFFF8 at the timing 1).
H
CS0 is asserted at this time.
3 The lower two bits of the mode vector is
used to set the bit width of external CS0
area ROM. According to this, the reset
vector is fetched from external address
000FFFFC .
H
CS0 is asserted at this time.
4 Load the reset vector fetched at 3) to the
internal PC.
5 Internal 4K byte ROM is enabled according
to the mode vector fetched at 2) after
completion of 4).
6 The program starts running.
Each CS area is according to the bus width/
area set by _csinit called from the startup
routine.
■ An Example of Connection of External Memory
Given below is an example of connection of the MB91302A-010 to external memory. External
memory on the target must include ROM (addresses 400FE000
as this area is referenced by the real-time OS) for storing code and RAM (starting at address
10000000
The MB91302A-010 "outputs the CS0 signal in response to access to any address after
initialization by a reset" and "has the address upper bits (A31 to A24) decoded by CS signals".
When released from the reset, therefore, the MB91302A-010 can fetch mode vector (at address
000FFFF8
400FFFFC
532
after being released from the reset. Depending on the next operation of the
H
) for storing work data. Be sure to set ROM to CS0.
H
) and reset vector (at address 000FFFFC
H
of external ROM.
H
Remarks
The CS0 signal is asserted upon any external access.
For the MB91302A-010, set the MD2 to MD0 mode pins
to "LLH". (External vector mode)
For the mode vector, set 04
the CS0 bus width.
Set CS0 to the external ROM that stores the R_eit area
(addresses 400FFC00 to 400FFFFF
H
All address areas are accessed as CS0 until bus setting
by _csinit.
The startup routine must therefore be located always in
CS0.
) from actual addresses 400FFFF8
H
and 400FFFFC
H H
, 05 , or 06 depending on
H H H
).
H
to 400FFFFF are mandatory
H H
and
H
in the
and
H