Mitsubishi microcomputers
M16C / 62T Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
29
Processor Mode
Figure 1.9.1. Processor mode register 0 and 1
Processor mode register 0 (Note 1)
Symbol
Address
When reset
PM0
000416
0016 (Note 2)
Bit name
Function
Bit symbol
W
R
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 P40 to P43 function
select bit (Note 3)
0 : Address output
1 : Port function
(Address is not output)
BCLK output disable bit
0 : BCLK is output
1 : BCLK is not output
(Pin is left floating)
Processor mode register 1 (Note 1)
Symbol
Address
When reset
PM1
000516
00000XX02
Bit name
Function
Bit symbol
W
R
b7
b6
b5
b4
b3
b2
b1
b0
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”
0
PM17
Wait bit
0 : No wait state
1 : Wait state inserted
Memory area
expansion bit (Note 2)
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
Reserved bit
Must always be set to “0”
0
Note 1: Set bit 1 of the protect register (address 000A16) to “1” when writing new values to this register.
Note 2: If the VCC voltage is applied to the CNVSS, the value of this register when reset is 0316.
(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.
Note 5: The M16C/62T group is not guaranteed to operate in memory expansion and microprocessor modes.
Note 1: Set bit 1 of the protect register (address 000A16) to “1” when writing new values to this register.
Note 2: 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”.
Note 3: The M16C/62T group is not guaranteed to operate in memory expansion and microprocessor modes.
Reserved bit
Must always be set to “0”
Reserved bit
Must always be set to “0”