Fujitsu F2 MC-8FX Family, Hardware Manual

Page: 234 / 602

220
CHAPTER 15 WILD REGISTER
15.1 Overview of Wild Register
The wild register function can be used to patch the program which has the bugs by
specifying the addresses and substitute data in internal registers. The primary purpose
of this register is to substitute ROM code in the ROM space. The wild register consists
of 3-byte data setting registers, 3-byte upper address setting registers, 3-byte lower
address setting registers, a 1-byte address compare enable register, and a 1-byte data
test register. The wild register function is described below.
■
Wild Register Function
The wild register consists of three data setting registers, three upper address setting registers, three lower
address setting registers, a 1-byte address compare enable register, and a 1-byte data test register. You can
substitute new data at specific addresses by specifying the addresses and data in these registers. Up to three
bytes of data can be set in the three data setting registers. Similarly, up to three different addresses can be
set
in the three upper and lower address setting registers.
You can use the wild register function to substitute ROM code anywhere in the ROM space. This can be
used for program debugging after creating the mask or to patch bugs in the program. This is done by setting
up the wild registers from an external device via the communication bus.