Operating Description Of Wild Register - Fujitsu F2MC-8FX Hardware Manual

15.4

Operating Description of Wild Register

This section describes the setup procedure for the wild register.
Setup Procedure for Wild Register
Prepare a special program that can read the value to be set in the wild register from external memory (e.g.
2
E PROM or FRAM) in the user program before executing the program. The setup method for the wild
register is shown below. It should be noted that this section does not explain how to communicate between
the external memory and the device.
• Write the address of the built-in ROM code that will be modified to the wild register address setup
register (WRAR0 to WRAR2).
• Write a new code into the corresponding wild register data setup register (WRDR0 to WRDR2).
• Write to the corresponding bits in the wild register address compare enable register (WREN) to enable
the wild register function.
Table 15.4-1 shows the register setup procedure for the wild register.
Table 15.4-1 Register Setup Procedure for Wild Register
Operating step
Read replacement data from outside through its
1
specific communication method.
Write the replacement address into the wild register
2
address setup register (WRAR0 to WRAR2).
Write a new ROM code (replacement for the built-in
3 ROM code) to the wild register data setup register
(WRDR0 to WRDR2).
When substituting more than one internal ROM
4 code, repeat this for wild registers 1 to 3. Data can
be modified for a maximum of three addresses
Enable the corresponding bits in the wild register
5
address compare enable register (WREN).
Wild Register Applicable Addresses
The wild register is applicable to all addresses in the address space except "0078
As address "0078
address cannot be patched.
Operation
" is used as a mirror address for the register bank pointer and direct bank pointer, this
H
CHAPTER 15 WILD REGISTER
Example operation
Set the built-in ROM code to be modified is in the address
F011 and the data to be modified to B5
H
codes can be modified.
Set wild register address setup registers (WRAR0 = F011
WRAR1 = ..., WRAR2 = ...).
Set the wild register data setup registers (WRDR0 = B5
WRDR1 =..., WRDR2 =...).
Repeat steps 1 to 3
Setting bit 0 of the address compare enable register (WREN) to
"1" enables the wild register function for the wild register
number 1. If the address matches the value set in the address
setup register (WRAR), the value of the data setup register
(WRDR) will replace the built-in ROM code. When replacing
more than one built-in ROM code, enable the corresponding
bits of the address compare enable register (WREN).
. Three built-in ROM
H
,
H
,
H
".
H
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