DF2211NP24V Renesas Technology / Hitachi Semiconductor, DF2211NP24V Datasheet - Page 182

• Manufacturer Part Number: DF2211NP24V
• Description: H8S/2200 Series, 2212 Group, USB, RTC, HSS TNP-64B; Vcc= 2.7 to 3.6 volts, Temp= -20 to 75 C; Package: PVQN0064LB-A
• Manufacturer: Renesas Technology / Hitachi Semiconductor

Section 6 Bus Controller
6.4.2
Bus Specifications
The external space bus specifications consist of three elements: bus width, number of access states,
and number of program wait states.
The bus width and number of access states for memory and internal I/O registers except for the on-
chip USB and RTC are fixed, and are not affected by the bus controller.
Bus Width: A bus width of 8 or 16 bits can be selected with ABWCR. An area for which an 8-bit
bus is selected functions as an 8-bit access space, and an area for which a 16-bit bus is selected
functions as a16-bit access space.
If all areas are designated for 8-bit access, 8-bit bus mode is set; if any area is designated for 16-bit
access, 16-bit bus mode is set. When the burst ROM interface is designated, 16-bit bus mode is
always set. 8-bit bus mode should be set for area 6 and area 7 in this LSI.
Number of Access States: Two or three access states can be selected with ASTCR.
An area for which 2-state access is selected functions as a 2-state access space, and an area for
which 3-state access is selected functions as a 3-state access space.
With the burst ROM interface, the number of access states may be determined without regard to
ASTCR.
When 2-state access space is designated, wait insertion is disabled.
Area 6 and area 7 should be set to function as a 3-state access space in this LSI.
Number of Program Wait States: When 3-state access space is designated by ASTCR, the
number of program wait states to be inserted automatically is selected with WCRH and WCRL.
From 0 to 3 program wait states can be selected.
The number of program wait states in area 6 and area 7 should be set to 0 in this LSI.
Rev.7.00 Dec. 24, 2008 Page 128 of 698
REJ09B0074-0700