h8s-2172 Renesas Electronics Corporation., h8s-2172 Datasheet - Page 144

• Manufacturer Part Number: h8s-2172
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family H8s-2100 Series
• Manufacturer: Renesas Electronics Corporation.

8-Bit, 3-State Access Space: Figure 6.12 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.
When all areas are designated as 8-bit space, the LWR pin can be used as the I/O port. However,
when all areas are designated as 16-bit space, the LWR pin is always fixed high. Wait states can
be inserted.
Rev. 2.00, 03/04, page 112 of 534
Notes: 1. n = 3 to 0
Read
Write
2. When RDNn = 0
φ
Address bus
D15 to D8
D7 to D0
D15 to D8
D7 to D0
Figure 6.12 Bus Timing for 8-Bit, 3-State Access Space
T
1
High impedance
Bus cycle
High
T
2
Valid
T
3
Invalid
Valid