M16C30P_07 Datasheet, PDF (52/317 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/30 SERIES

M16C/30P Group
7. Bus
Example 1
To access the external area indicated by CSj in the next cycle after
accessing the external area indicated by CSi
The address bus and the chip select signal both change state between
these two cycles.
Example 2
To access the internal ROM or internal RAM in the next cycle after
accessing the external area indicated by CSi
The chip select signal changes state but the address bus does not
change state
Access to the external Access to the external
area indicated by CSi area indicated by CSj
BCLK
Read signal
Data bus
Address bus
CSi
CSj
Data Data
Address Address
Access to the external Access to the internal
area indicated by CSi ROM or internal RAM
BCLK
Read signal
Data bus
Address bus
CSi
Data
Address
Example 3
To access the external area indicated by CSi in the next cycle after
accessing the external area indicated by the same CSi
Example 4
Not to access any area (nor instruction prefetch generated) in the next cycle after
accessing the external area indicated by CSi
The address bus changes state but the chip select signal does not
change state
Neither the address bus nor the chip select signal changes state between
these two cycles
Access to the external Access to the same
area indicated by CSi external area
Access to the external No access
area indicated by CSi
BCLK
Read signal
Data bus
Address bus
CSi
Data Data
Address Address
BCLK
Read signal
Data bus
Address bus
CSi
Data
Address
NOTES :
1. These examples show the address bus and chip select signal when accessing areas in two successive cycles. The chip select bus cycle
may be extended more than two cycles depending on a combination of these examples.
Shown above is the case where separate bus is selected and the area is accessed for read without wait states. i = 0 to 3, j = 0 to 3
(not including i, however)
Figure 7.2 Example of Address Bus and CSi Signal Output in 1-Mbyte mode
Rev.1.22 Mar 29, 2007 Page 36 of 291
REJ09B0179-0122