Renesas H8S Family Hardware Manual page 180

Section 6 Bus Controller (BSC)
Address bus
IOS (IOSE = 1)
CS256 (CS256E = 1)
AS (IOSE = 0)
*
Read
Write
Note: * For external address space access, this signal is not output when the 256-Kbyte extended area
is accessed with CS256E = 1.
Figure 6.8 Bus Timing for 16-Bit, 2-State Access Space (Odd Byte Access)
Rev. 1.00 Mar. 12, 2008 Page 132 of 1178
REJ09B0403-0100
φ
RD
D15 to D8
D7 to D0
HWR
LWR
D15 to D8
D7 to D0
Bus cycle
T T
1 2
Invalid
Valid
High level
Undefined
Valid