RL78/F13, F14 CHAPTER 27 SAFETY FUNCTIONS
R01UH0368EJ0210 Rev.2.10 1601
Dec 10, 2015
27.3.7 SFR guard function
This SFR guard function is used to protect data in the control registers used by the port function, interrupt function, clock
control function, and voltage detector.
If the SFR guard function is specified, writing to the specified SFRs is disabled, but reading from the SFRs can be carried
out as usual.
<Control register>
(1) Invalid memory access detection control register (IAWCTL)
This register is used to control the detection of invalid memory access and RAM/SFR guard function.
GPORT, GINT and GCSC bits are used in SFR guard function.
The IAWCTL register can be set by an 8-bit memory manipulation instruction.
Reset signal generation clears this register to 00H.
Figure 27-20. Format of Invalid Memory Access Detection Control Register (IAWCTL)
Address: F0078H After reset: 00H R/W
Symbol 7 6 5 4 3 2 1 0
IAWCTL IAWEN 0 GRAM1 GRAM0 0 GPORT GINT GCSC
GPORT Control registers of port function guard
0 Disabled. Control registers of port function can be read or written to.
1 Enabled. Writing to control registers of port function is disabled. Reading is enabled.
[Guarded SFR] PMxx, PUxx, PIMxx, POMxx, PMCxx, PITHLxx, ADPC, PIOR
Note
GINT Registers of interrupt function guard
0 Disabled. Registers of interrupt function can be read or written to.
1 Enabled. Writing to registers of interrupt function is disabled. Reading is enabled.
[Guarded SFR] IFxx, MKxx, PRxx, EGPx, EGNx
GCSC
Control registers of clock control function and voltage detector guard
0 Disabled. Control registers of clock control function and voltage detector can be read or written to.
1
Enabled. Writing to control registers of clock control function and voltage detector is disabled. Reading
is enabled.
[Guarded SFR] CMC, CSC, OSTS, CKC, PERx, OSMC, LVIM, LVIS, CANCKSEL, LINCKSEL,
CKSEL, PLLCTL, MDIV, RTCCL, POCRES, STPSTC
Note Pxx (Port register) is not guarded.
<R>
To Next Page
Loading...
Need help?
General
