h8s-2138 Renesas Electronics Corporation., h8s-2138 Datasheet - Page 204

• Manufacturer Part Number: h8s-2138
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 6 Bus Controller
8-Bit 3-State Access Space: Figure 6.6 shows the bus timing for an 8-bit 3-state access space.
When an 8-bit access space is accessed, the upper half (D15 to D8) of the data bus is used.
Wait states can be inserted.
These group have no lower data bus (D7 to D0) pins or LWR pin. In these group, the upper data
bus (D15 to D8) pins are designated D7 to D0, and the HWR signal pin is designated WR.
Rev. 4.00 Jun 06, 2006 page 150 of 1004
REJ09B0301-0400
Read
Write
AS/IOS (IOSE = 1)
AS/IOS (IOSE = 0)
Address bus
D15 to D8
D15 to D8
D7 to D0
HWR
RD
Figure 6.6 Bus Timing for 8-Bit 3-State Access Space
T
1
Bus cycle
T
2
Valid
T
3
Invalid
Valid