HD6412332 RENESAS [Renesas Technology Corp], HD6412332 Datasheet - Page 202

• Manufacturer Part Number: HD6412332
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 6 Bus Controller
6.5.8
Wait Control
There are two ways of inserting wait states in a DRAM access cycle: program wait insertion and
pin wait insertion using the WAIT pin.
Program Wait Insertion: When the bit in ASTCR corresponding to an area designated as DRAM
space is set to 1, from 0 to 3 wait states can be inserted automatically between the T
state and T
c1
c2
state, according to the settings of WCRH and WCRL.
Pin Wait Insertion: When the WAITE bit in BCRH is set to 1, wait input by means of the WAIT
pin is enabled. When DRAM space is accessed in this state, a program wait is first inserted. If the
WAIT pin is low at the falling edge of φ in the last T
or T
state, another T
state is inserted. If
c1
w
w
the WAIT pin is held low, T
states are inserted until it goes high.
w
Figure 6.17 shows an example of wait state insertion timing.
Rev.4.00 Sep. 07, 2007 Page 172 of 1210
REJ09B0245-0400