Mitsubishi microcomputers
M16C / 62 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Processor Mode
28
Figure 1.9.1. Processor mode register 0 and 1
Processor mode register 0 (Note 1)
Symbol
PM0
Address
0004
16
When reset
00
16
(Note 2)
Bit name
Function
Bit symbol
b7
b6
b5
b4
b3
b2
b1
b0
0 0: Single-chip mode
0 1: Memory expansion mode
1 0: Inhibited
1 1: Microprocessor mode
b1 b0
PM03
PM01
PM00
Processor mode bit
PM02
R/W mode select bit
0 : RD,BHE,WR
1 : RD,WRH,WRL
Software reset bit
The device is reset when this bit is set
to “1”. The value of this bit is “0” when
read.
PM04
0 0 : Multiplexed bus is not used
0 1 : Allocated to CS2 space
1 0 : Allocated to CS1 space
1 1 : Allocated to entire space (Note4)
b5 b4
Multiplexed bus space
select bit
PM05
PM06
PM07
Port P4
0
to P4
3
function
select bit (Note 3)
0 : Address output
1 : Port function
(Address is not output)
0 : BCLK is output
1 : BCLK is not output
(Pin is left floating)
BCLK output disable bit
Note 1: Set bit 1 of the protect register (address 000A
16
) to “1” when writing new
values to this register.
Note 2: If the V
CC
voltage is applied to the CNV
SS
, the value of this register when
reset is 03
16
. (PM00 and PM01 both are set to “1”.)
Note 3: Valid in microprocessor and memory expansion modes.
Note 4: If the entire space is of multiplexed bus in memory expansion mode, choose an 8-
bit width.The processor operates using the separate bus after reset is revoked, so the entire
space multiplexed bus cannot be chosen in microprocessor mode.
The higher-order address becomes a port if the entire space multiplexed bus is chosen, so
only 256 bytes can be used in each chip select.
Processor mode register 1 (Note 1)
Symbol
PM1
Address
0005
16
When reset
00000XX0
2
Bit name
Function
Bit symbol
W
R
b7
b6
0
b5
b4
b3
b2
b1
b0
0
Nothing is assigned.
In an attempt to write to these bits, write “0”. The value, if read, turns
out to be
indeterminate.
Reserved bit
Must always be set to “0”
Note 1: Set bit 1 of the protect register (address 000A
16
) to “1” when writing new values to this register.
Note 2: Be sure to set this bit to 0 except products whose RAM size and ROM size exceed 15K bytes
and 192K bytes respectively.
In using M30624MG/FG, a product having a RAM of more than 15K bytes and a ROM of more
than 192K bytes, set this bit to 1 at the beginning of user program.
Specify D0000
16
or a subsequent address, which becomes an internal ROM area if PM13 is set
to “0” at the time reset is revoked, for the reset vector table of user program.
Note 3: With the processor running in memory expansion mode or in microprocessor mode, setting this
bit provides the means of expanding the external memory area. (Normal mode: up to 1M byte,
expansion mode 1: up to 1.2 M bytes, expansion mode 2: up to 4M bytes)
For details, see “Memory space expansion functions”.
AA
AA
AA
A
A
A
AA
AA
A
A
A
AA
PM17
Wait bit
0 : No wait state
1 : Wait state inserted
AA
AA
AA
Memory area
expansion bit (Note 3)
0 0 : Normal mode
(Do not expand)
0 1 : Inhibited
1 0 : Memory area expansion
mode 1
1 1 : Memory area expansion
mode 2
b5 b4
PM15
PM14
A
A
Reserved bit
Must always be set to “0”
Internal reserved area
expansion bit (Note 2)
PM13
0: The same internal reserved
area as that of M16C/60 and
M16C/61 group
1: Expands the internal RAM area
and internal ROM area to 23 K
bytes and to 256K bytes
respectively. (Note 2)