105
Chapter 3
CPU Function
Preliminary User’s Manual U15839EE1V0UM00
3.6.2 Peripheral Command Register (PHCMD)
This command register (PHCMD) is to protect the registers that may have a significant influence on the
application system (CKC, WCC, PCC) from an inadvertent write access, so that the system does not
stop in case of a program hang-up.
This register can be only written in 8-bit units (undefined data is used when this register is read).
Only the first write access to a specific on-chip register (hereafter referred to as a “specific register”)
after data has been written to the PHCMD register is valid.
In this way, the value of the specific register can be rewritten only in a specified sequence, and an illegal
write access is inhibited.
Figure 3-18:
Peripheral Command Register (PHCMD) Format
REG7-0: registration code (any 8-bit data)
Caution:
The register must be written with store instruction execution by CPU. DMA transfer is
prohibited.
If an illegal store operation takes place, it can be checked by the PRERR flag of the peripheral status
register (PHS).
Caution:
Write to this register by DMA transfer is prohibited!
7
6
5
4
3
2
1
0
Address
R/W
At Reset
PHCMD
REG7
REG6
REG5
REG4
REG3
REG2
REG1
REG0
FFFFF800H
R/W
xxH
Summary of Contents for mPD703128
Page 6: ...6 Preliminary User s Manual U15839EE1V0UM00 ...
Page 20: ...20 Preliminary User s Manual U15839EE1V0UM00 ...
Page 32: ...32 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 154: ...154 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 238: ...238 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 356: ...356 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 522: ...522 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 600: ...600 Preliminary User s Manual U15839EE1V0UM00 MEMO ...
Page 610: ...610 Preliminary User s Manual U15839EE1V0UM00 ...
Page 612: ......