Section 6 Bus Controller
Rev. 3.00 Jan 25, 2006 page 114 of 872
REJ09B0286-0300
Wait Mode and Number of Program Wait States:
When a 3-state access space is designated by
the AST bit in WSCR, the wait mode and the number of program wait states to be inserted
automatically is selected by the WMS1, WMS0, WC1, and WC0 bits in WSCR. From 0 to 3
program wait states can be selected.
When the 256-kbyte expansion area is specified as a 3-state access space by the AST256 bit in
WSCR, the wait mode and the number of program wait states to be inserted automatically is
selected by the WMS10, WC11, and WC10 bits in WSCR2. From 0 to 3 program wait states can
be selected.
When the CP/CF expansion area is specified as a 3-state access space by the ASTCP bit in BCR2,
the wait mode and the number of program wait states to be inserted automatically is selected by
the WMS21, WMS20, WC21, and WC20 bits in WSCR2. From 0 to 3 program wait states can be
selected.
When the CP expansion area is set to the CF expansion area (memory card mode) by the CFE bit
in BCR, the wait mode and the number of program wait states to be inserted automatically is
selected by the WMS21, WMS20, WC22, WC21, and WC20 bits in WSCR2. From 0 to 4, 6, 8, or
10 program wait states can be selected.
The wait function for external expansion is effective for connecting low-speed devices to the
external address space. However, this wait function may cause some problems when bus masters
other than the CPU, such as the DTC and RFU are to be delayed. The RFU is mostly used for data
transmission and reception of interface peripheral modules. In this case, the wait function for
external expansion may cause difficulty in making data transfer satisfy the communication rate of
transmit/receive data of the interface peripheral modules. To prevent such a problem, it is
recommended that when using the RFT, the external address space should be designated as a 2-
state or 3-state access space with no wait state.
Tables 6.2 to 6.7 show each bit setting and external address space division in the address ranges of
the external address space, and the bus specifications for the basic bus interface of each area.
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...