M16C6NK Datasheet, PDF (65/404 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/60 SERIES

Under development
This document is under development and its contents are subject to change.
M16C/6N Group (M16C/6NK, M16C/6NM)
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.
Access to the external Access to the external
area indicated by CSi area indicated by CSj
Example 2
To access the internal ROM or internal RAM in the next cycle
after accessing the external area indicated by CSi.
The chip s elect s ignal c hanges state but the address bus
does not change state.
Access to the external Access to the internal
area indicated by CSi ROM or internal RAM
BCLK
Read signal
Data bus
Address bus
CSi
CSj
Data Data
Address Address
BCLK
Read signal
Data bus
Address bus
CSi
Data
Address
Example 3
To a ccess the external area indicated by CSi in the next cycle
after accessing the external area indicated by the same CSi.
The address bus changes state but t he c hip select signal
does not change state.
Example 4
Not to access any area (nor instruction prefetch generated)
in the next cycle after accessing the external area indicated
by CSi.
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
NOTE:
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)
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Figure 7.2 Example of Address Bus and CSi Signal Output
Rev.2.00 Nov 28, 2005 page 47 of 378
REJ09B0124-0200