M16C6K9 Datasheet, PDF (27/292 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

M16C/6K9 Group
Software Reset
Software Reset
Writing “1” to bit 3 of the processor mode register 0 (address 000416) applies a (software) reset to the
microcomputer. A software reset has almost the same effect as a hardware reset. The contents of internal
RAM are retained.
Processor Mode
(1) Types of Processor Mode
The single-chip mode is supported in processor mode.
• Single-chip mode
In single-chip mode, only internal memory space (SFR, internal RAM, and internal ROM) can be accessed.
Ports P0 to P16 can be used as programmable I/O ports or as I/O ports for the internal peripheral functions.
Fig. BG-1 shows the structure of processor mode register 0 and processor mode register 1.
Processor mode register 0 (Note 1)
b7 b6 b5 b4 b3 b2 b1 b0
0000
0
Symbol
PM0
Address
000416
When reset
0016 (Note 2)
Bit symbol
Bit name
PM00
Processor mode bit
PM01
Reserved bit
PM03
Software reset bit
Reserved bit
Function
b1 b0
0 0: Single-chip mode
0 1: Inhibited
1 0: Inhibited
1 1: Inhibited
Must always be set to “0”
RW
The device is reset when this bit is set
to “1”. The value of this bit is “0” when
read.
Must always be set to “0”
Note 1: Set bit 1 of the protect register (address 000A16) to “1” when writing new
values to this register.
Processor mode register 1 (Note 1)
b7 b6 b5 b4 b3 b2 b1 b0
0 00 0
0
Symbol
PM1
Address
000516
When reset
00000XX02
Bit symbol
Bit name
Function
RW
Reserved bit
Must always be set to “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”
PM17
Wait bit
0 : No wait state
1 : Wait state inserted
Note 1: Set bit 1 of the protect register (address 000A16) to “1” when writing new
values to this register.
Fig.BG-1 Processor mode register 0 and 1
Rev.1.00 Jun 06, 2003 page 27 of 290