h8s-2646 Renesas Electronics Corporation., h8s-2646 Datasheet - Page 96

• Manufacturer Part Number: h8s-2646
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 2 CPU
2.9
2.9.1
The H8S/2600 CPU is driven by a system clock, denoted by the symbol φ. The period from one
rising edge of φ to the next is referred to as a "state." The memory cycle or bus cycle consists of
one, two, or three states. Different methods are used to access on-chip memory, on-chip
supporting modules, and the external address space.
2.9.2
On-chip memory is accessed in one state. The data bus is 16 bits wide, permitting both byte and
word transfer instruction. Figure 2.17 shows the on-chip memory access cycle. Figure 2.18 shows
the pin states.
Rev. 5.00 Sep 22, 2005 page 70 of 1136
REJ09B0257-0500
Basic Timing
Overview
On-Chip Memory (ROM, RAM)
Internal address bus
Read
access
Write
access
Internal read signal
Internal data bus
Internal write signal
Internal data bus
Figure 2.17 On-Chip Memory Access Cycle
Bus cycle
Address
T1
Read data
Write data