HD6412240 RENESAS [Renesas Technology Corp], HD6412240 Datasheet - Page 104

• Manufacturer Part Number: HD6412240
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family / H8S/2200 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 2 CPU
2.9
2.9.1
The H8S/2000 CPU is driven by a system clock, denoted by the symbol . The period from one
rising edge of 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.3.00 Mar. 26, 2007 Page 62 of 772
REJ09B0355-0300
Overview
On-Chip Memory (ROM, RAM)
Basic Timing
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