Section 6 Bus Controller
Rev. 3.00 Jan 25, 2006 page 122 of 872
REJ09B0286-0300
6.4.3
Normal Mode
The external address space is initialized as the basic bus interface and a 3-state access space. In
mode 3 (normal mode), the address space other than on-chip ROM, on-chip RAM, internal I/O
registers, and their reserved areas is specified as the external address space. The on-chip RAM
area is enabled when the 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
I/O Select Signals
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.
Bus cycle
T
1
T
2
Address bus
φ
IOS
T
3
External addresses selected by IOS
Figure 6.2
IOS
IOS
IOS
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 9, 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 6.8.
Table 6.8
Address Range for
IOS
IOS
IOS
IOS
Signal Output
IOS1
IOS0
IOS
IOS
IOS
IOS
Signal Output Range
0
H'(FF)F000 to H'(FF)F03F
0
1
H'(FF)F000 to H'(FF)F0FF
0
H'(FF)F000 to H'(FF)F3FF
1
1
H'(FF)F000 to H'(FF)F7FF
(Initial value)
Summary of Contents for H8S/2158
Page 10: ...Rev 3 00 Jan 25 2006 page viii of lii...
Page 36: ...Rev 3 00 Jan 25 2006 page xxxiv of lii B Product Lineup 863 C Package Dimensions 864 Index 865...
Page 47: ...Rev 3 00 Jan 25 2006 page xlv of lii Appendix Figure C 1 Package Dimensions TBP 112A 864...
Page 54: ...Rev 3 00 Jan 25 2006 page lii of lii...
Page 70: ...Section 1 Overview Rev 3 00 Jan 25 2006 page 16 of 872 REJ09B0286 0300...
Page 118: ...Section 3 MCU Operating Modes Rev 3 00 Jan 25 2006 page 64 of 872 REJ09B0286 0300...
Page 126: ...Section 4 Exception Handling Rev 3 00 Jan 25 2006 page 72 of 872 REJ09B0286 0300...
Page 198: ...Section 6 Bus Controller Rev 3 00 Jan 25 2006 page 144 of 872 REJ09B0286 0300...
Page 326: ...Section 10 8 Bit PWM Timer PWM Rev 3 00 Jan 25 2006 page 272 of 872 REJ09B0286 0300...
Page 440: ...Section 15 Watchdog Timer WDT Rev 3 00 Jan 25 2006 page 386 of 872 REJ09B0286 0300...
Page 606: ...Section 17 I 2 C Bus Interface IIC Rev 3 00 Jan 25 2006 page 552 of 872 REJ09B0286 0300...
Page 742: ...Section 19 Multimedia Card Interface MCIF Rev 3 00 Jan 25 2006 page 688 of 872 REJ09B0286 0300...
Page 750: ...Section 21 D A Converter Rev 3 00 Jan 25 2006 page 696 of 872 REJ09B0286 0300...
Page 768: ...Section 22 A D Converter Rev 3 00 Jan 25 2006 page 714 of 872 REJ09B0286 0300...
Page 770: ...Section 23 RAM Rev 3 00 Jan 25 2006 page 716 of 872 REJ09B0286 0300...
Page 824: ...Section 26 Clock Pulse Generator Rev 3 00 Jan 25 2006 page 770 of 872 REJ09B0286 0300...
Page 844: ...Section 27 Power Down Modes Rev 3 00 Jan 25 2006 page 790 of 872 REJ09B0286 0300...
Page 878: ...Section 28 List of Registers Rev 3 00 Jan 25 2006 page 824 of 872 REJ09B0286 0300...
Page 926: ...Index Rev 3 00 Jan 25 2006 page 872 of 872 REJ09B0286 0300...