HD6473032F16 Datasheet, PDF (164/847 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

Section 6 Bus Controller
• Pin Auto-Wait Mode
If the WAIT pin is low, the number of wait states (T_W) selected by bits WC1 and WC0 are
inserted.
In pin auto-wait mode, if the WAIT pin is low at the fall of the system clock (φ) in the T₂ state,
the number of wait states (T_W) selected by bits WC1 and WC0 are inserted. No additional wait
states are inserted even if the WAIT pin remains low. Pin auto-wait mode can be used for an
easy interface to low-speed memory, simply by routing the chip select signal to the WAIT pin.
Figure 6.14 shows the timing when the wait count is 1.
T₁
T₂
T₃
T₁
T₂
T_W
T₃
φ
*
*
WAIT
Address bus
External address
External address
AS
Read
access
RD
Data bus
Read data
Read data
Write
access
HWR, LWR
Data bus
Write data
Write data
Note: * Arrows indicate time of sampling of the WAIT pin.
Figure 6.14 Pin Auto-Wait Mode
Rev. 3.00 Mar 21, 2006 page 134 of 814
REJ09B0302-0300