
7. Processor Mode
Figure 7.1
PM0 Register
b7 b6 b5 b4
b1
b2
b3
Processor Mode Register 0(1)
Symbol
PM0
Address
0004h
Bit Symbol
Bit Name
RW
After Reset
1000 0000b
b0
Function
0
PM00
RW
b1 b0
0 0: Single-chip mode
0 1: Memory expansion mode(8)
1 0: Do not set to this value
1 1: Do not set to this value
Processor mode bits(2, 3)
PM01
PM02
R/W mode select bit
0: RD/BHE/WR
1: RD/WRH/WRL
PM03
Software reset bit
The MCU is reset when this bit is set to 1.
When read, the content is 0
PM04
Multiplex bus space
select bits(4)
b5 b4
0 0: Multiplex bus is not used
0 1: Access the CS2 area using the bus
1 0: Access the CS1 area using the bus
1 1: Access all CS areas using the bus(5)
PM05
(b6)
Reserved bit
BCLK output disable bit(6)
Set to 0
PM07
0: BCLK output(7)
1: No BCLK output
Bits CM01 and CM00 in the CM0 register
determine pin functions
RW
NOTES:
1. Set the PM0 register after the PRC1 bit in the PRCR register is set to 1 (write enable).
2. Bits PM01 and PM00 maintain values set before reset, even after software reset or watchdog timer reset has been performed.
3. Do not set bits PM07 to PM02 at the same time as setting bits PM01 and PM00 to 01b. Set bits PM07 to PM02 before bits
PM01 and PM00 are set.
4. The following settings are enabled in memory expansion mode.
Set bits PM05 and PM04 to "00b" in external memory space mode 0.
Do not set bits PM05 and PM04 to 01b in external memory space mode 2.
5. When bits PM05 and PM04 are set to "11b" in memory expansion mode, the accessible space for each chip select is selected
from either 64 Kbytes or 256 bytes using the PM30 in the PM3 register. The multiplex bus is not available in mode 0. The MCU
accesses the CS0 to CS2 in mode 1, CS0 and CS1 in mode 2 and CS0 to CS3 in mode 3.
6. No BCLK is output in single-chip mode even if the PM07 bit is set to 0.
To abort a clock output in memory expansion mode, set the PM07 bit to 1 and bits CM01 and CM00 in the CM0 register to "00b"
(P5_3 as I/O port). P5_3 outputs "L".
7. When the PM07 bit is set to 0, set bits CM01 and CM00 to 00b.
8. High-reliability version cannot be used in memory expansion mode.