7.1
Overview
The H8/3842R, H8/3843R, H8/38342, H8/38343, H8/38442, and H8/38443 have 1 Kbytes of
high-speed static RAM, and H8/3844R, H8/3844S, H8/38344, H8/38444, H8/3845R, H8/3845S,
H8/38345, H8/38445, H8/3846R, H8/3846S, H8/38346, H8/38446, H8/3847R, H8/3847S,
H8/38347, and H8/38447 have 2 Kbytes of high-speed static RAM on-chip. The RAM is
connected to the CPU by a 16-bit data bus, allowing high-speed 2-state access for both byte data
and word data.
7.1.1
Block Diagram
Figure 7.1 shows a block diagram of the on-chip RAM.
H'F780
H'F782
H'FF7E
Figure 7.1 RAM Block Diagram (H8/3844R, H8/3844S, H8/38344 and H8/38444)
Section 7 RAM
Internal data bus (upper 8 bits)
Internal data bus (lower 8 bits)
H'F780
H'F782
On-chip RAM
H'FF7E
Even-numbered
address
H'F781
H'F783
H'FF7F
Odd-numbered
address
Rev. 6.00 Aug 04, 2006 page 201 of 680
Section 7 RAM
REJ09B0145-0600