h8s-2161b Renesas Electronics Corporation., h8s-2161b Datasheet - Page 182

• Manufacturer Part Number: h8s-2161b
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 6 Bus Controller (BSC)
RAME bit in SYSCR is set to 1, and disabled and specified as the external address space when the
RAME bit is cleared to 0.
6.4.4
The LSI can output I/O select signals (IOS); the signal is driven low when the corresponding
external address space is accessed. Figure 6.2 shows an example of IOS signal output timing.
Enabling or disabling IOS signal output is performed by the IOSE bit in SYSCR. In extended
mode, the IOS pin functions as an AS pin by a reset. To use this pin as an IOS pin, set the IOSE
bit to 1. For details, refer to section 8, I/O Ports.
The address ranges of the IOS signal output can be specified by the IOS1 and IOS0 bits in BCR,
as shown in table 6.3.
Table 6.3
IOS1
0
1
Rev. 3.00 Mar 21, 2006 page 128 of 788
REJ09B0300-0300
I/O Select Signals
Address Range for IOS
IOS0
0
1
0
1
Address bus
IOS
Figure 6.2 IOS
IOS
IOS
IOS
IOS Signal Output Range
H'(FF)F000 to H'(FF)F03F
H'(FF)F000 to H'(FF)F0FF
H'(FF)F000 to H'(FF)F3FF
H'(FF)F000 to H'(FF)F7FF
IOS Signal Output
IOS
IOS
T
1
IOS
IOS
IOS Signal Output Timing
External addresses selected by IOS
Bus cycle
T
2
T
3
(Initial value)