CHAPTER 6 BUS CONTROL
User’s Manual U14272EJ3V0UM
111
6.2.1 BCUCNTREG1 (0x0A00 0000)
Bit
15
14
13
12
11
10
9
8
Name
ROMs1
ROMs0
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
R/W
R/W
R/W
R
R
R
R
R
R
At reset
1
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
Name
Reserved
Reserved
Reserved
ROMWEN0
Reserved
Rtype1
Rtype0
RSTOUT
R/W
R
R
R
R/W
R
R/W
R/W
R/W
At reset
0
0
0
0
0
0
0
0
Bit
Name
Function
15, 14
ROMs(1:0)
Defines ROM size to be used (for all banks)
00 : Reserved
01 : 32 Mbit
10 : 64 Mbit
11 : Reserved
13 to 5
Reserved
0 is returned when read
4
ROMWEN0
Enables flash memory write (for all banks). Write strobe can be generated when
this bit is set to 1.
0 : Disabled
1 : Enabled
3
Reserved
0 is returned when read
2, 1
Rtype(1:0)
ROM type (for all banks)
00 : Ordinary ROM
01 : Flash memory
10 : Page ROM
11 : Reserved
0
RSTOUT
RESET# output control. This bit does not affect GPIO21/RESET# pin’s state when
this pin is not defined as RESET# output.
0 : RESET# is active (low level)
1 : RESET# is inactive (high level)
This register is used to set ROM type and capacity of ROM Bank 0, 1, 2 and 3.
Caution
When writing to flash memory, be sure to set Rtype(1:0) bits to 01 in addition to a setting of
ROMWEN0 bit to 1.
Remark
When a ROM type other than flash memory is selected (Rtype(1:0) bits are set to other than 01), the
operation of the V
R
4181 is undefined if a write to the ROM space is performed.