YR0K42378FC000BA Renesas Electronics America, YR0K42378FC000BA Datasheet - Page 255

• Manufacturer Part Number: YR0K42378FC000BA
• Description: KIT EVAL FOR H8S/2378
• Manufacturer: Renesas Electronics America
• Series: H8®r
• Type: MCUr

Specifications of YR0K42378FC000BA

• Contents: Board
• For Use With/related Products: H8S/2378
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Section 6 Bus Controller (BSC)
6.5.4
Wait Control
When accessing external space, this LSI can extend the bus cycle by inserting one or more wait
states (T
). There are two ways of inserting wait states: program wait insertion and pin wait
w
insertion using the WAIT pin.
Program Wait Insertion: From 0 to 7 wait states can be inserted automatically between the T
2
state and T
state on an individual area basis in 3-state access space, according to the settings in
3
WTCRA and WTCRB.
Pin Wait Insertion: Setting the WAITE bit to 1 in BCR enables wait input by means of the
WAIT pin. When external space is accessed in this state, a program wait is first inserted in
accordance with the settings in WTCRA and WTCRB. If the WAIT pin is low at the falling edge
state is inserted. If the WAIT pin is held low, T
of φ in the last T
or T
state, another T
states
2
w
w
w
are inserted until it goes high. This is useful when inserting seven or more T
states, or when
w
changing the number of T
states to be inserted for different external devices. The WAITE bit
w
setting applies to all areas. Figure 6.18 shows an example of wait state insertion timing.
The settings after a reset are: 3-state access, insertion of 7 program wait states, and WAIT input
disabled.
Rev.7.00 Mar. 18, 2009 page 187 of 1136
REJ09B0109-0700