Chip Selects And Address Bus - Renesas M16C Series User Manual

M30245 Group

4.2.2 Chip Selects and Address Bus

Chip selects (P4
memory space into four. To use the chip select, the chip select output must be enabled by setting the
chip select control register. Figure 4.2.2 shows addresses in which chip selects become active ("L").
Since the extent of the internal area and the external area in memory expansion mode is different from
those in microprocessor mode, there is a difference between areas for which CS0 is output. When an
internal ROM/RAM area is being accessed, no chip select is output, and the address bus does not
change (the address of the external area that was accessed previously is held).
www.DataSheet4U.com
0 0 0 0 0
1 6
0 0 3 F F
1 6
0 0 4 0 0
1 6
X X X X X
1 6
0 3 F F F
1 6
04000
16
0 7 F F F
1 6
0 8 0 0 0
1 6
2 7 F F F
1 6
28000
16
2FFFF
16
3 0 0 0 0
1 6
C F F F F
1 6
D0000
16
Y Y Y Y Y
1 6
F F F F F
1 6
Figure 4.2.2. Addresses in which chip selects turn active ("L")
Rev.2.00 Oct 16, 2006
REJ09B0340-0200
______ ______
/CS0 through P4 /CS3) are output in areas resulting from dividing a 1-M byte
4 7
S F R a r e a
I n t e r n a l R A M a r e a
I n t e r n a l r e s e r v e d a r e a
I n t e r n a l r e s e r v e d a r e a
I n t e r n a l R O M a r e a
M e m o r y e x p a n s i o n m o d e
page 332 of 354
P a r t n u m b e r A d d r e s s X X X X X
M 3 0 2 4 5 F C G P
M 3 0 2 4 5 M C - X X X G P
M 3 0 2 4 5 M 8 - X X X G P
CS3
04000 to 07FFF (16K)
16 16
C S 2
0 8 0 0 0 t o 2 7 F F F ( 1 2 8 K )
1 6 1 6
C S 1
2 8 0 0 0 t o 2 F F F F ( 3 2 K )
1 6 1 6
C S 0
3 0 0 0 0 t o C F F F F ( 6 4 0 K )
1 6 1 6
4. External Buses
_______
A d d r e s s Y Y Y Y Y
1 6 1 6
02BFF E0000
16 16
0 2 B F F E 0 0 0 0
1 6 1 6
0 1 7 F F F 0 0 0 0
1 6 1 6
CS3
04000 to 07FFF (16K)
16 16
C S 2
0 8 0 0 0 t o 2 7 F F F ( 1 2 8 K )
1 6 1 6
C S 1
2 8 0 0 0 t o 2 F F F F ( 3 2 K )
1 6 1 6
C S 0
3 0 0 0 0 t o F F F F F ( 8 3 2 K )
1 6 1 6
M e m o r y e x p a n s i o n m o d e