HD6432621 Hitachi, HD6432621 Datasheet - Page 655

• Manufacturer Part Number: HD6432621
• Description: (HD64F262x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

18.1
The H8S/2626 and H8S/2623 have 12 kbytes of on-chip high-speed static RAM, the H8S/2625
and H8S/2622 have 8 kbytes, and the H8S/2624 and H8S/2621 have 4 kbytes. The RAM is
connected to the CPU by a 16-bit data bus, enabling one-state access by the CPU to both byte data
and word data. This makes it possible to perform fast word data transfer.
The on-chip RAM can be enabled or disabled by means of the RAM enable bit (RAME) in the
system control register (SYSCR).
18.1.1
Figure 18-1 shows a block diagram of the on-chip RAM.
Overview
Block Diagram
Figure 18-1 Block Diagram of RAM (H8S/2623)
H'FFC000
H'FFC002
H'FFC004
H'FFEFBE
H'FFFFC0
H'FFFFFE
Section 18 RAM
Internal data bus (upper 8 bits)
Internal data bus (lower 8 bits)
H'FFEFBF
H'FFFFC1
H'FFC001
H'FFC003
H'FFC005
H'FFFFFF
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