R01UH0092EJ0110 Rev.1.10
Page 142 of 807
Jul 31, 2012
M16C/64C Group
11. Bus
11.3.2
Internal Bus
The internal bus is used to access the internal area in the MCU.
11.3.2.1
Software Wait States of the Internal Bus
The PM17 bit in the PM1 register, which is a software-wait-related bit, affects both the internal
memory and the external area. Table 11.3 lists Bits and Bus Cycles Related to Software Wait States
(SFR and Internal Memory).
The data flash of the internal ROM is affected by both the PM17 bit in the PM1 register and the
FMR17 bit in the FMR1 register.
Table 11.3
Bits and Bus Cycles Related to Software Wait States (SFR and Internal Memory)
Area
Setting of Software-Wait-Related Bits
Software Wait
States
Bus Cycle
FMR1 register
FMR17 bit
PM1 register
PM17 bit
SFR
0 or 1
0 or 1
1
2 BCLK cycles
(1)
Internal RAM
0 or 1
0
None
1 BCLK cycle
(1)
1
1
2 BCLK cycles
Internal
ROM
Program ROM 1
Program ROM 2
0 or 1
0
None
1 BCLK cycle
(1)
1
1
2 BCLK cycles
Data flash
0
0 or 1
1
2 BCLK cycles
(1)
1
0
None
1 BCLK cycle
1
1
2 BCLK cycle
Note:
1.
Status after reset.
Summary of Contents for M16C Series
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