
CHAPTER 3 CPU FUNCTION
User’s Manual U16541EJ5V1UD
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3.4.7
Programmable peripheral I/O registers
The BPC register is used for programmable peripheral I/O register area selection.
(1) Peripheral I/O area select control register (BPC)
The BPC register can be read or written in 16-bit units.
Reset sets this register to 0000H.
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Address
Default value
BPC PA15
0
PA13 PA12 PA11 PA10 PA09 PA08 PA07 PA06 PA05 PA04 PA03 PA02 PA01 PA00 FFFFF064H
0000H
Bit position
Bit name
Function
Enables/disables usage of programmable peripheral I/O area.
PA15
Usage of programmable peripheral I/O area
0
Usage of programmable peripheral I/O area disabled
1
Usage of programmable peripheral I/O area enabled
15
PA15
13 to 0
PA13 to PA00
Specify an address in programmable peripheral I/O area (corresponding to A27 to A14,
respectively).
Caution
When setting the PA15 bit to 1, be sure to set the BPC register to 8FFBH.
When clearing the PA15 bit to 0, be sure to set the BPC register to 0000H.
For a list of the programmable peripheral I/O register areas, see Table 19-16 Register Access Types.
3.4.8
Special registers
Special registers are registers that are protected from being written with illegal data due to a program hang-up. The
V850ES/SG2 and V850ES/SG2-H have eight and seven special registers, respectively.
Power save control register (PSC)
Clock control register (CKC)
Processor clock control register (PCC)
Clock monitor mode register (CLM)
Reset source flag register (RESF)
Low voltage detection register (LVIM)Note
Internal RAM data status register (RAMS)
On-chip debug mode register (OCDM)
Note
V850ES/SG2 only
In addition, the PRCDM register is provided to protect against a write access to the special registers so that the
application system does not inadvertently stop due to a program hang-up. A write access to the special registers is
made in a specific sequence, and an illegal store operation is reported to the SYS register.
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