
CHAPTER 5 BUS CONTROL FUNCTION
User’s Manual U15905EJ2V1UD
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5.3.1
Chip select control function
Of the 64 MB (linear) address space, the lower 16 MB (0000000H to 0FFFFFFH) include four chip select functions,
CS0 to CS3. The areas that can be selected by CS0 to CS3 are fixed.
By using these chip select functions, the memory block can be divided to enable effective use of the memory
space. The allocation of the memory blocks is shown in the table below.
V850ES/SA2
V850ES/SA3
CS0
0000000H to 01FFFFFH (2 MB)
CS1
0200000H to 03FFFFFH (2 MB)
CS2
0400000H to 07FFFFFH (4 MB)
CS3
0800000H to 0BFFFFFH (4 MB)
0800000H to 0FFFFFFH (8 MB)
5.4
External Bus Interface Mode Control Function
The V850ES/SA2 and V850ES/SA3 include the following two external bus interface modes.
Multiplexed bus mode
Separate bus mode
These two modes can be selected by using the external bus interface mode control register (EXIMC).
(1) External bus interface mode control register (EXIMC)
This register can be read or written in 8-bit or 1-bit units.
This register is cleared to 00H after reset.
0
Multiplexed bus mode
Separate bus mode
SMSEL
0
1
Mode selection
EXIMC
0
SMSEL
After reset: 00H
R/W
Address: FFFFFFBEH