Section 16 Ram; Overview; Block Diagram; System Control Register (Syscr) - Hitachi H8S/2338 Series Hardware Manual

16.1

Overview

The H8S/2338 Series, H8S/2328 Series, and H8S/2318 Series have on-chip high-speed static
RAM. 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).

The amount of on-chip RAM differs from model to model; please check the reference manual for
the relevant model for confirmation.
16.1.1

Block Diagram

Figure 16-1 shows a block diagram of 8 kbytes of on-chip RAM.

Section 16 RAM

Internal data bus (upper 8 bits)
Internal data bus (lower 8 bits)
H'FFDC00
H'FFDC02
H'FFDC04
H'FFFBFE
Figure 16-1 Block Diagram of RAM (8 kbytes)
H'FFDC01
H'FFDC03
H'FFDC05
H'FFFBFF
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