H8S2138 Datasheet, PDF (627/1061 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2100 Series

Section 20 RAM
Section 20 RAM
20.1 Overview
The H8S/2138, H8S/2134, and H8S/2133 have 4 kbytes of on-chip high-speed static RAM, and
the H8S/2137, H8S/2132, and H8S/2130 have 2 kbytes. The on-chip RAM is connected to the
CPU by a 16-bit data bus, enabling both byte data and word data to be accessed in one state. 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).
20.1.1 Block Diagram
Figure 20.1 shows a block diagram of the on-chip RAM.
Internal data bus (upper 8 bits)
Internal data bus (lower 8 bits)
H'FFE080
H'FFE082
H'FFE084
H'FFE081
H'FFE083
H'FFE085
H'FFEFFE
H'FFFF00
H'FFEFFF
H'FFFF01
H'FFFF7E
H'FFFF7F
Figure 20.1 Block Diagram of RAM (H8S/2138, H8S/2134, H8S/2133)
Rev. 4.00 Jun 06, 2006 page 573 of 1004
REJ09B0301-0400